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Sample records for organischen stoffgruppen pak

  1. Mouse models of PAK function.

    PubMed

    Kelly, Mollie L; Chernoff, Jonathan

    2012-04-01

    p21-activated kinases are a family of highly conserved protein serine/threonine kinases that are increasingly recognized as playing essential roles in a variety of key signaling processes. Genetic analyses in mice, using constitutive or regulated gene disruption, have provided important new insights into PAK function. In this paper, we review the genetic analysis of all six PAK genes in mice. These data address the singular and redundant functions of the various PAK genes and suggest therapeutic possibilities for small molecule PAK inhibitors or activators. PMID:23162740

  2. Pyrolysis of the tetra pak

    SciTech Connect

    Korkmaz, Ahmet; Yanik, Jale Brebu, Mihai; Vasile, Cornelia

    2009-11-15

    This study deals with pyrolysis of tetra pak which is widely used as an aseptic beverage packaging material. Pyrolysis experiments were carried out under inert atmosphere in a batch reactor at different temperatures and by different pyrolysis modes (one- and two-step). The yields of char, liquid and gas were quantified. Pyrolysis liquids produced were collected as three separate phases; aqueous phase, tar and polyethylene wax. Characterization of wax and the determination of the total amount of phenols in aqueous phase were performed. Chemical compositions of gas and char products relevant to fuel applications were determined. Pure aluminum can be also recovered by pyrolysis.

  3. Crystal Structures of the p21-Activated Kinases PAK4, PAK5, and PAK6 Reveal Catalytic Domain Plasticity of Active Group II PAKs

    PubMed Central

    Eswaran, Jeyanthy; Lee, Wen Hwa; Debreczeni, Judit É.; Filippakopoulos, Panagis; Turnbull, Andrew; Fedorov, Oleg; Deacon, Sean W.; Peterson, Jeffrey R.; Knapp, Stefan

    2007-01-01

    Summary p21-activated kinases have been classified into two groups based on their domain architecture. Group II PAKs (PAK4–6) regulate a wide variety of cellular functions, and PAK deregulation has been linked to tumor development. Structural comparison of five high-resolution structures comprising all active, monophosphorylated group II catalytic domains revealed a surprising degree of domain plasticity, including a number of catalytically productive and nonproductive conformers. Rearrangements of helix αC, a key regulatory element of kinase function, resulted in an additional helical turn at the αC N terminus and a distortion of its C terminus, a movement hitherto unseen in protein kinases. The observed structural changes led to the formation of interactions between conserved residues that structurally link the glycine-rich loop, αC, and the activation segment and firmly anchor αC in an active conformation. Inhibitor screening identified six potent PAK inhibitors from which a tri-substituted purine inhibitor was cocrystallized with PAK4 and PAK5. PMID:17292838

  4. Republished: Tracing PAKs from GI inflammation to cancer

    PubMed Central

    Dammann, Kyle; Khare, Vineeta; Gasche, Christoph

    2014-01-01

    P-21 activated kinases (PAKs) are effectors of Rac1/Cdc42 which coordinate signals from the cell membrane to the nucleus. Activation of PAKs drive important signalling pathways including mitogen activated protein kinase, phospoinositide 3-kinase (PI3K/AKT), NF-κB and Wnt/β-catenin. Intestinal PAK1 expression increases with inflammation and malignant transformation, although the biological relevance of PAKs in the development and progression of GI disease is only incompletely understood. This review highlights the importance of altered PAK activation within GI inflammation, emphasises its effect on oncogenic signalling and discusses PAKs as therapeutic targets of chemoprevention. PMID:25335797

  5. PAK in pathogen-host interactions

    PubMed Central

    Semblat, Jean-Philippe; Doerig, Christian

    2012-01-01

    Eukaryotic, prokaryotic and viral pathogens are known to interfere with signaling pathways of their host to promote their own survival and proliferation. Here, we present selected examples of modulation of PAK activity in human cells by both intracellular and extracellular pathogens, focusing on one eukaryotic pathogen, the human malaria parasite Plasmodium falciparum, two Gram-negative bacteria (Helicobacter pylori and Pseudomonas aeruginosa), and two viruses belonging to distinct groups, the lentivirus HIV and the orthomyxovirus Influenza virus A. PMID:23125952

  6. Pak Signaling in the Development and Progression of Cancer

    PubMed Central

    Radu, Maria; Semenova, Galina; Kosoff, Rachelle; Chernoff, Jonathan

    2014-01-01

    p21-activated kinases (Paks) are positioned at the nexus of several oncogenic signaling pathways. Overexpression or mutational activation of Pak isoforms is frequently seen in various human tumors, and recent data suggests that excessive Pak activity drives many cellular processes that are the hallmarks of cancer. In this review, we discuss the mechanisms of Pak activation in cancer, the key substrates for this family of kinases that mediate their developmental and oncogenic effects, and how small molecule inhibitors of these enzymes might best be developed and deployed in the treatment of cancer. PMID:24505617

  7. PAK5 is auto-activated by a central domain that promotes kinase oligomerization.

    PubMed

    Tabanifar, Bahareh; Zhao, Zhuoshen; Manser, Ed

    2016-06-15

    PAKs (p21 activated kinases) are an important class of Rho effectors. These contain a Cdc42-Rac1 interaction and binding (CRIB) domain and a flanking auto-inhibitory domain (AID) which binds the C-terminal catalytic domain. The group II kinases PAK4 and PAK5 are considered significant therapeutic targets in cancer. Among human cancer cell lines we tested, PAK5 protein levels are much lower than those of PAK4, even in NCI-H446 which has the highest PAK5 mRNA expression. Although these two kinases are evolutionarily and structurally related, it has never been established why PAK4 is inactive whereas PAK5 has high basal activity. The AID of PAK5 is functionally indistinguishable from that of PAK4, pointing to other regions being responsible for higher activity of PAK5. Gel filtration indicates PAK4 is a monomer but PAK5 is dimeric. The central region of PAK5 (residues 109-420) is shown here to promote self-association, and an elevated activity, but has no effect on activation loop Ser(602) phosphorylation. These residues allow PAK5 to form characteristic puncta in cells, and removing sequences involved in oligomerization suppresses kinase activity. Our model suggests PAK5 self-association interferes with AID binding to the catalytic domain, thus maintaining its high activity. Further, our model explains the observation that PAK5 (1-180) inhibits PAK5 in vitro. PMID:27095851

  8. Herbal therapeutics that block the oncogenic kinase PAK1: a practical approach towards PAK1-dependent diseases and longevity.

    PubMed

    Maruta, Hiroshi

    2014-05-01

    Over 35 years research on PAKs, RAC/CDC42(p21)-activated kinases, comes of age, and in particular PAK1 has been well known to be responsible for a variety of diseases such as cancer (mainly solid tumors), Alzheimer's disease, acquired immune deficiency syndrome and other viral/bacterial infections, inflammatory diseases (asthma and arthritis), diabetes (type 2), neurofibromatosis, tuberous sclerosis, epilepsy, depression, schizophrenia, learning disability, autism, etc. Although several distinct synthetic PAK1-blockers have been recently developed, no FDA-approved PAK1 blockers are available on the market as yet. Thus, patients suffering from these PAK1-dependent diseases have to rely on solely a variety of herbal therapeutics such as propolis and curcumin that block PAK1 without affecting normal cell growth. Furthermore, several recent studies revealed that some of these herbal therapeutics significantly extend the lifespan of nematodes (C. elegans) and fruit flies (Drosophila), and PAK1-deficient worm lives longer than the wild type. Here, I outline mainly pathological phenotypes of hyper-activated PAK1 and a list of herbal therapeutics that block PAK1, but cause no side (harmful) effect on healthy people or animals. PMID:23943274

  9. PAKS--Arbeitsbericht Nr. 5. Juli 1970. [PAKS--Working Paper No. 5. July 1970.

    ERIC Educational Resources Information Center

    Stuttgart Univ. (Germany).

    This report, the fifth in a series of working papers issued by the Project on Applied Contrastive Linguistics (PAKS) at the University of Stuttgart, is dedicated to a consideration of error analysis in language learning, here seen as relevant not only for the teacher but for the text book writer and the curriculum planner as well. An introduction…

  10. Substrate and Inhibitor Specificity of the Type II p21-Activated Kinase, PAK6

    PubMed Central

    Gao, Jia; Ha, Byung Hak; Lou, Hua Jane; Morse, Elizabeth M.; Zhang, Rong; Calderwood, David A.; Turk, Benjamin E.; Boggon, Titus J.

    2013-01-01

    The p21-activated kinases (PAKs) are important effectors of Rho-family small GTPases. The PAK family consists of two groups, type I and type II, which have different modes of regulation and signaling. PAK6, a type II PAK, influences behavior and locomotor function in mice and has an ascribed role in androgen receptor signaling. Here we show that PAK6 has a peptide substrate specificity very similar to the other type II PAKs, PAK4 and PAK5 (PAK7). We find that PAK6 catalytic activity is inhibited by a peptide corresponding to its N-terminal pseudosubstrate. Introduction of a melanoma-associated mutation, P52L, into this peptide reduces pseudosubstrate autoinhibition of PAK6, and increases phosphorylation of its substrate PACSIN1 (Syndapin I) in cells. Finally we determine two co-crystal structures of PAK6 catalytic domain in complex with ATP-competitive inhibitors. We determined the 1.4 Å co-crystal structure of PAK6 with the type II PAK inhibitor PF-3758309, and the 1.95 Å co-crystal structure of PAK6 with sunitinib. These findings provide new insights into the structure-function relationships of PAK6 and may facilitate development of PAK6 targeted therapies. PMID:24204982

  11. Pak2 restrains endomitosis during megakaryopoiesis and alters cytoskeleton organization

    PubMed Central

    Kosoff, Rachelle E.; Aslan, Joseph E.; Kostyak, John C.; Dulaimi, Essel; Chow, Hoi Yee; Prudnikova, Tatiana Y.; Radu, Maria; Kunapuli, Satya P.; McCarty, Owen J. T.

    2015-01-01

    Megakaryocyte maturation and polyploidization are critical for platelet production; abnormalities in these processes are associated with myeloproliferative disorders, including thrombocytopenia. Megakaryocyte maturation signals through cascades that involve p21-activated kinase (Pak) function; however, the specific role for Pak kinases in megakaryocyte biology remains elusive. Here, we identify Pak2 as an essential effector of megakaryocyte maturation, polyploidization, and proplatelet formation. Genetic deletion of Pak2 in murine bone marrow is associated with macrothrombocytopenia, altered megakaryocyte ultrastructure, increased bone marrow megakaryocyte precursors, and an elevation of mature CD41+ megakaryocytes, as well as an increased number of polyploid cells. In Pak2−/− mice, platelet clearance rate was increased, as was production of newly synthesized, reticulated platelets. In vitro, Pak2−/− megakaryocytes demonstrate increased polyploidization associated with alterations in β1-tubulin expression and organization, decreased proplatelet extensions, and reduced phosphorylation of the endomitosis regulators LIM domain kinase 1, cofilin, and Aurora A/B/C. Together, these data establish a novel role for Pak2 as an important regulator of megakaryopoiesis, polyploidization, and cytoskeletal dynamics in developing megakaryocytes. PMID:25824689

  12. The Retinoblastoma Tumor Suppressor Transcriptionally Represses Pak1 in Osteoblasts

    PubMed Central

    Sosa-García, Bernadette; Vázquez-Rivera, Viviana; González-Flores, Jonathan N.; Engel, Brienne E.; Cress, W. Douglas; Santiago-Cardona, Pedro G.

    2015-01-01

    We previously characterized the retinoblastoma tumor suppressor protein (Rb) as a regulator of adherens junction assembly and cell-to-cell adhesion in osteoblasts. This is a novel function since Rb is predominantly known as a cell cycle repressor. Herein, we characterized the molecular mechanisms by which Rb performs this function, hypothesizing that Rb controls the activity of known regulators of adherens junction assembly. We found that Rb represses the expression of the p21-activated protein kinase (Pak1), an effector of the small Rho GTPase Rac1. Rac1 is a well-known regulator of adherens junction assembly whose increased activity in cancer is linked to perturbations of intercellular adhesion. Using nuclear run-on and luciferase reporter transcription assays, we found that Pak1 repression by Rb is transcriptional, without affecting Pak1 mRNA and protein stability. Pak1 promoter bioinformatics showed multiple E2F1 binding sites within 155 base pairs of the transcriptional start site, and a Pak1-promoter region containing these E2F sites is susceptible to transcriptional inhibition by Rb. Chromatin immunoprecipitations showed that an Rb-E2F complex binds to the region of the Pak1 promoter containing the E2F1 binding sites, suggesting that Pak1 is an E2F target and that the repressive effect of Rb on Pak1 involves blocking the trans-activating capacity of E2F. A bioinformatics analysis showed elevated Pak1 expression in several solid tumors relative to adjacent normal tissue, with both Pak1 and E2F increased relative to normal tissue in breast cancer, supporting a cancer etiology for Pak1 up-regulation. Therefore, we propose that by repressing Pak1 expression, Rb prevents Rac1 hyperactivity usually associated with cancer and related to cytoskeletal derangements that disrupt cell adhesion, consequently enhancing cancer cell migratory capacity. This de-regulation of cell adhesion due to Rb loss could be part of the molecular events associated with cancer progression

  13. PAK1 translocates into nucleus in response to prolactin but not to estrogen.

    PubMed

    Oladimeji, Peter; Diakonova, Maria

    2016-04-22

    Tyrosyl phosphorylation of the p21-activated serine-threonine kinase 1 (PAK1) has an essential role in regulating PAK1 functions in breast cancer cells. We previously demonstrated that PAK1 serves as a common node for estrogen (E2)- and prolactin (PRL)-dependent pathways. We hypothesize herein that intracellular localization of PAK1 is affected by PRL and E2 treatments differently. We demonstrate by immunocytochemical analysis that PAK1 nuclear translocation is ligand-dependent: only PRL but not E2 stimulated PAK1 nuclear translocation. Tyrosyl phosphorylation of PAK1 is essential for this nuclear translocation because phospho-tyrosyl-deficient PAK1 Y3F mutant is retained in the cytoplasm in response to PRL. We confirmed these data by Western blot analysis of subcellular fractions. In 30 min of PRL treatment, only 48% of pTyr-PAK1 is retained in the cytoplasm of PAK1 WT clone while 52% re-distributes into the nucleus and pTyr-PAK1 shuttles back to the cytoplasm by 60 min of PRL treatment. In contrast, PAK1 Y3F is retained in the cytoplasm. E2 treatment causes nuclear translocation of neither PAK1 WT nor PAK1 Y3F. Finally, we show by an in vitro kinase assay that PRL but not E2 stimulates PAK1 kinase activity in the nuclear fraction. Thus, PAK1 nuclear translocation is ligand-dependent: PRL activates PAK1 and induces translocation of activated pTyr-PAK1 into nucleus while E2 activates pTyr-PAK1 only in the cytoplasm. PMID:27003261

  14. Modular vault dry storage at Paks NPP technology and experience

    SciTech Connect

    Bower, C.C.F.; Szabo, B.

    1995-12-31

    Paks NPP in Hungary, with its four VVER440 reactors, generates 50% of Hungary`s electricity. In 1990, it was faced with an uncertain future due to the changing political situation in Eastern Europe. The fuel storage ponds were rapidly filling up, with no secure route for disposal. The paper outlines the Paks approach to resolving the problem and the background to its chosen solution, concluding with a review of the experience of other applications of the system.

  15. Clathrin-independent endocytosis used by the IL-2 receptor is regulated by Rac1, Pak1 and Pak2

    PubMed Central

    Grassart, Alexandre; Dujeancourt, Annick; Lazarow, Paul B; Dautry-Varsat, Alice; Sauvonnet, Nathalie

    2008-01-01

    There are several endocytic pathways, which are either dependent on or independent of clathrin. This study focuses on a poorly characterized mechanism—clathrin- and caveolae-independent endocytosis—used by the interleukin-2 receptor β (IL-2Rβ). We address the question of its regulation in comparison with the clathrin-dependent pathway. First, we show that Ras-related C3 botulinum toxin substrate 1 (Rac1) is specifically required for IL-2Rβ entry, and we identify p21-activated kinases (Paks) as downstream targets. By RNA interference, we show that Pak1 and Pak2 are both necessary for IL-2Rβ uptake, in contrast to the clathrin-dependent route. We observe that cortactin, a partner of actin and dynamin—two essential endocytic factors—is required for IL-2Rβ uptake. Furthermore, we find that cortactin acts downstream from Paks, suggesting control of its function by these kinases. Thus, we describe a cascade composed of Rac1, Paks and cortactin specifically regulating IL-2Rβ internalization. This study indicates Paks as the first specific regulators of the clathrin-independent endocytosis pathway. PMID:18344974

  16. Clathrin-independent endocytosis used by the IL-2 receptor is regulated by Rac1, Pak1 and Pak2.

    PubMed

    Grassart, Alexandre; Dujeancourt, Annick; Lazarow, Paul B; Dautry-Varsat, Alice; Sauvonnet, Nathalie

    2008-04-01

    There are several endocytic pathways, which are either dependent on or independent of clathrin. This study focuses on a poorly characterized mechanism-clathrin- and caveolae-independent endocytosis-used by the interleukin-2 receptor beta (IL-2R beta). We address the question of its regulation in comparison with the clathrin-dependent pathway. First, we show that Ras-related C3 botulinum toxin substrate 1 (Rac1) is specifically required for IL-2R beta entry, and we identify p21-activated kinases (Paks) as downstream targets. By RNA interference, we show that Pak1 and Pak2 are both necessary for IL-2R beta uptake, in contrast to the clathrin-dependent route. We observe that cortactin, a partner of actin and dynamin-two essential endocytic factors-is required for IL-2R beta uptake. Furthermore, we find that cortactin acts downstream from Paks, suggesting control of its function by these kinases. Thus, we describe a cascade composed of Rac1, Paks and cortactin specifically regulating IL-2R beta internalization. This study indicates Paks as the first specific regulators of the clathrin-independent endocytosis pathway. PMID:18344974

  17. 3D structure analysis of PAKs: A clue to the rational design for affinity reagents and blockers.

    PubMed

    Jha, Ramesh K; Strauss, Charlie E M

    2012-04-01

    The p21-activated kinase (PAK) family plays a versatile role in cell signaling by forming a hub of interactions. PAKs bind the GTPases like RAC and CDC42. Their proline-rich motifs bind SH3 adaptor proteins such as PIX and NCK. PAKs display nuclear localization signal sites and a potential Integrin binding site. No fully complete structure of the PAKs has been published; partial 3D structures of the PAK family kinases include portions of the auto-inhibited PAK1, GTPase bound to small peptides from PAKs, and the kinase domains from PAK1 and PAK4-6 (with small ligands in a few cases). This review focuses on exploring the intermolecular interaction regions in these 3D structures and we offer insights on the missing regions in crystal structure of the auto-inhibited PAK1. Understanding and modulation of PAK intermolecular interactions can pave the way for PAK blockers and biosensors. PMID:23162739

  18. Development of a Hydronic Rooftop Unit-HyPak-MA

    SciTech Connect

    Lee, Eric; Berman, Mark

    2009-11-14

    The majority of U.S. commercial floor space is cooled by rooftop HVAC units (RTUs). RTU popularity derives chiefly from their low initial cost and relative ease of service access without disturbing building occupants. Unfortunately, current RTUs are inherently inefficient due to a combination of characteristics that unnecessarily increase cooling loads and energy use. 36% percent of annual U.S. energy, and two-thirds of electricity, is consumed in and by buildings. Commercial buildings consume approximately 4.2 quads of energy each year at a cost of $230 billion per year, with HVAC equipment consuming 1.2 quads of electricity. More than half of all U.S. commercial floor space is cooled by packaged HVAC units, most of which are rooftop units (RTUs). Inefficient RTUs create an estimated 3.5% of U.S. CO{sub 2} emissions, thus contributing significantly to global warming5. Also, RTUs often fail to maintain adequate ventilation air and air filtration, reducing indoor air quality. This is the second HyPak project to be supported by DOE through NETL. The prior project, referred to as HyPak-1 in this report, had two rounds of prototype fabrication and testing as well as computer modeling and market research. The HyPak-1 prototypes demonstrated the high performance capabilities of the HyPak concept, but made it clear that further development was required to reduce heat exchanger cost and improve system reliability before HyPak commercialization can commence. The HyPak-1 prototypes were limited to about 25% ventilation air fraction, limiting performance and marketability. The current project is intended to develop a 'mixed-air' product that is capable of full 0-100% modulation in ventilation air fraction, hence it was referred to as HyPak-MA in the proposal. (For simplicity, the -MA has been dropped when referencing the current project.) The objective of the HyPak Project is to design, develop and test a hydronic RTU that provides a quantum improvement over conventional RTU

  19. PAK4 promotes kinase-independent stabilization of RhoU to modulate cell adhesion

    PubMed Central

    Dart, Anna E.; Box, Gary M.; Court, William; Gale, Madeline E.; Brown, John P.; Pinder, Sarah E.; Eccles, Suzanne A.

    2015-01-01

    P21-activated kinase 4 (PAK4) is a Cdc42 effector protein thought to regulate cell adhesion disassembly in a kinase-dependent manner. We found that PAK4 expression is significantly higher in high-grade human breast cancer patient samples, whereas depletion of PAK4 modifies cell adhesion dynamics of breast cancer cells. Surprisingly, systematic analysis of PAK4 functionality revealed that PAK4-driven adhesion turnover is neither dependent on Cdc42 binding nor kinase activity. Rather, reduced expression of PAK4 leads to a concomitant loss of RhoU expression. We report that RhoU is targeted for ubiquitination by the Rab40A–Cullin 5 complex and demonstrate that PAK4 protects RhoU from ubiquitination in a kinase-independent manner. Overexpression of RhoU rescues the PAK4 depletion phenotype, whereas loss of RhoU expression reduces cell adhesion turnover and migration. These data support a new kinase-independent mechanism for PAK4 function, where an important role of PAK4 in cellular adhesions is to stabilize RhoU protein levels. Thus, PAK4 and RhoU cooperate to drive adhesion turnover and promote cell migration. PMID:26598620

  20. Zip Pak for Pre-Primer Reading Level (Teacher's Manual).

    ERIC Educational Resources Information Center

    Scott, Norval C., Comp.

    The Zip Pak for the pre-primer reading level was developed for use with migrant Mexican American children with reading deficiencies. Its goals are to: (1) increase and widen the child's ability to be selective in choosing his information and selecting information pertinent to a purpose; and (2) improve the child's ability to make decisions,…

  1. Zip Pak for Pre-Primer Reading Level.

    ERIC Educational Resources Information Center

    Scott, Norval C., Comp.

    The Zip Pak for the pre-primer reading level was developed for use with migrant Mexican American children who have reading deficiencies. The area of failure with these children has not been with the visual discrimination involved in decoding, but with the interpretation of the material to be decoded. Therefore, the 5 lessons in this student…

  2. Zip Pak for Second Reader Level (Teacher's Manual).

    ERIC Educational Resources Information Center

    Scott, Norval C., Comp.

    Developed for use with migrant children between the ages of 8 and 12 years, working at a second grade level, this Zip Pak was created to give additional aid in reading and vocabulary building. Since the speaking vocabulary of these children tends to be normal while their reading and writing vocabulary tends to be low, an attempt was made to…

  3. Pak1 as a Novel Therapeutic Target for Anti-Hypertrophic Treatment in the Heart

    PubMed Central

    Liu, Wei; Zi, Min; Naumann, Ronald; Ulm, Susanne; Jin, Jiawei; Taglieri, Domenico M.; Prehar, Sukhpal; Gui, Junhong; Tsui, Hoyee; Xiao, Rui-Ping; Neyses, Ludwig; Solaro, R. John; Ke, Yunbo; Cartwright, Elizabeth J.; Lei, Ming; Wang, Xin

    2011-01-01

    Background Stress-induced hypertrophic remodeling is a critical pathogenetic process leading to heart failure. While many signal transduction cascades are demonstrated as important regulators to facilitate the induction of cardiac hypertrophy, the signaling pathways for suppressing hypertrophic remodeling remain largely unexplored. In this study, we identified p21-activated kinase 1 (Pak1) as a novel signaling regulator which antagonizes cardiac hypertrophy. Methods and Results Hypertrophic stress applied to primary neonatal rat cardiomyocytes (NRCMs), or murine hearts caused the activation of Pak1. Analysis of NRCMs expressing constitutively active Pak1 or in which Pak1 was silenced disclosed that Pak1 played an anti-hypertrophic role. To investigate the in vivo role of Pak1 in the heart, we generated mice with a cardiomyocyte-specific deletion of Pak1 (Pak1cko). When subject to 2 weeks of pressure overload, Pak1cko mice compared to controls, developed greater cardiac hypertrophy with attendant blunting of JNK activation, and these knockout mice underwent the transition into heart failure when prolonged stress was applied. In addition, chronic angiotensin II infusion also caused increased cardiac hypertrophy in Pak1cko mice. Moreover, we discovered that the Pak1 activator FTY720, a sphingosine-like analogue, was able to prevent pressure overload-induced hypertrophy in wild-type mice, without compromising their cardiac functions. Meanwhile FTY720 failed to exert such an effect on Pak1cko mice, suggesting that the anti-hypertrophic effect of FTY720 likely acts through Pak1 activation. Conclusions These results, for the first time, establish Pak1 as a novel anti-hypertrophic regulator and suggest that it may be a potential therapeutic target for the treatment of cardiac hypertrophy and heart failure. PMID:22082674

  4. P21-activated kinase 2 (PAK2) regulates glucose uptake and insulin sensitivity in neuronal cells.

    PubMed

    Varshney, Pallavi; Dey, Chinmoy Sankar

    2016-07-01

    P21-activated kinases (PAKs) are recently reported as important players of insulin signaling and glucose homeostasis in tissues like muscle, pancreas and liver. However, their role in neuronal insulin signaling is still unknown. Present study reports the involvement of PAK2 in neuronal insulin signaling, glucose uptake and insulin resistance. Irrespective of insulin sensitivity, insulin stimulation decreased PAK2 activity. PAK2 downregulation displayed marked enhancement of GLUT4 translocation with increase in glucose uptake whereas PAK2 over-expression showed its reduction. Treatment with Akti-1/2 and wortmannin suggested that Akt and PI3K are mediators of insulin effect on PAK2 and glucose uptake. Rac1 inhibition demonstrated decreased PAK2 activity while inhibition of PP2A resulted in increased PAK2 activity, with corresponding changes in glucose uptake. Taken together, present study demonstrates an inhibitory role of insulin signaling (via PI3K-Akt) and PP2A on PAK2 activity and establishes PAK2 as a Rac1-dependent negative regulator of neuronal glucose uptake and insulin sensitivity. PMID:27040307

  5. Lethality of PAK3 and SGK2 shRNAs to Human Papillomavirus Positive Cervical Cancer Cells Is Independent of PAK3 and SGK2 Knockdown

    PubMed Central

    Zhou, Nannan; Ding, Bo; Agler, Michele; Cockett, Mark; McPhee, Fiona

    2015-01-01

    The p21-activated kinase 3 (PAK3) and the serum and glucocorticoid-induced kinase 2 (SGK2) have been previously proposed as essential kinases for human papillomavirus positive (HPV+) cervical cancer cell survival. This was established using a shRNA knockdown approach. To validate PAK3 and SGK2 as potential targets for HPV+ cervical cancer therapy, the relationship between shRNA-induced phenotypes in HPV+ cervical cancer cells and PAK3 or SGK2 knockdown was carefully examined. We observed that the phenotypes of HPV+ cervical cancer cells induced by various PAK3 and SGK2 shRNAs could not be rescued by complement expression of respective cDNA constructs. A knockdown-deficient PAK3 shRNA with a single mismatch was sufficient to inhibit HeLa cell growth to a similar extent as wild-type PAK3 shRNA. The HPV+ cervical cancer cells were also susceptible to several non-human target shRNAs. The discrepancy between PAK3 and SGK2 shRNA-induced apoptosis and gene expression knockdown, as well as cell death stimulation, suggested that these shRNAs killed HeLa cells through different pathways that may not be target-specific. These data demonstrated that HPV+ cervical cancer cell death was not associated with RNAi-induced PAK3 and SGK2 knockdown but likely through off-target effects. PMID:25615606

  6. Gene Expression Analysis of Pak Choi in Response to Vernalization

    PubMed Central

    Sun, Mengxia; Qi, Xianhui; Hou, Leiping; Xu, Xiaoyong; Zhu, Zhujun; Li, Meilan

    2015-01-01

    Pak choi is a seed vernalization-type plant whose vernalization mechanism is currently unclear. Therefore, it is critical to discover genes related to vernalization and research its functions during vernalization in pak choi. Here, the gene expression profiles in the shoot apex were analyzed after low temperature treatment using high-throughput RNA sequencing technology. The results showed that there are 1,664 and 1,192 differentially expressed genes (DEGs) in pak choi in cold treatment ending and before flower bud differentiation, respectively, including 42 genes that exhibited similar expression trend at both stages. Detailed annotation revealed that the proteins encoded by the DEGs are located in the extracellular region, cell junction and extracellular matrix. These proteins exhibit activity such as antioxidant activity and binding protein/transcription factor activity, and they are involved in signal transduction and the immune system/biological processes. Among the DEGs, Bra014527 was up-regulated in low temperature treatment ending, Bra024097 was up-regulated before flower bud differentiation and Bra035940 was down-regulated at both stages in low temperature-treated shoot apices. Homologues of these genes in A. thaliana, AT3G59790, AT4G30200 and AT5G61150, are involved in flowering and vernalization, suggesting that they take part in the vernalization process in pak choi. Further pathway enrichment analysis revealed that most genes were enriched in the tryptophan metabolism and glucosinolate biosynthesis pathways. However, the functions of tryptophan and glucosinolate in vernalization are not yet clear and require further analysis. PMID:26517271

  7. Optimization of a Dibenzodiazepine Hit to a Potent and Selective Allosteric PAK1 Inhibitor

    PubMed Central

    2015-01-01

    The discovery of inhibitors targeting novel allosteric kinase sites is very challenging. Such compounds, however, once identified could offer exquisite levels of selectivity across the kinome. Herein we report our structure-based optimization strategy of a dibenzodiazepine hit 1, discovered in a fragment-based screen, yielding highly potent and selective inhibitors of PAK1 such as 2 and 3. Compound 2 was cocrystallized with PAK1 to confirm binding to an allosteric site and to reveal novel key interactions. Compound 3 modulated PAK1 at the cellular level and due to its selectivity enabled valuable research to interrogate biological functions of the PAK1 kinase. PMID:26191365

  8. PAK-PIX interactions regulate adhesion dynamics and membrane protrusion to control neurite outgrowth.

    PubMed

    Santiago-Medina, Miguel; Gregus, Kelly A; Gomez, Timothy M

    2013-03-01

    The roles of P21-activated kinase (PAK) in the regulation of axon outgrowth downstream of extracellular matrix (ECM) proteins are poorly understood. Here we show that PAK1-3 and PIX are expressed in the developing spinal cord and differentially localize to point contacts and filopodial tips within motile growth cones. Using a specific interfering peptide called PAK18, we found that axon outgrowth is robustly stimulated on laminin by partial inhibition of PAK-PIX interactions and PAK function, whereas complete inhibition of PAK function stalls axon outgrowth. Furthermore, modest inhibition of PAK-PIX stimulates the assembly and turnover of growth cone point contacts, whereas strong inhibition over-stabilizes adhesions. Point mutations within PAK confirm the importance of PIX binding. Together our data suggest that regulation of PAK-PIX interactions in growth cones controls neurite outgrowth by influencing the activity of several important mediators of actin filament polymerization and retrograde flow, as well as integrin-dependent adhesion to laminin. PMID:23321640

  9. A School Improvement-Accountability Process Kit. PAK No. 3.1--Writing Student Objectives.

    ERIC Educational Resources Information Center

    Colorado State Dept. of Education, Denver. District Planning and Accountability Services.

    The purpose of this Personalized Activity Kit (PAK) is to provide a general introduction to the writing of student objectives. Ways are identified to write objectives that clearly describe the knowledge, skills, and attitudes that a school district believes its students ought to learn. The PAK further identifies ways to categorize objectives…

  10. Several herbal compounds in Okinawa plants directly inhibit the oncogenic/aging kinase PAK1.

    PubMed

    Nguyen, Binh Cao Quan; Taira, Nozomi; Tawata, Shinkichi

    2014-12-01

    The p21-activated kinase 1 (PAK1) is emerging as a promising therapeutic target, and the search for blockers of this oncogenic/aging kinase would be potentially useful for the treatment of various diseases/disorders in the future. Here, we report for the first time the anti-PAK1 activity of compounds derived from three distinct Okinawa plants. 5,6-Dehydrokawain (DK) and dihydro-5,6-dehydrokawain (DDK) from alpinia inhibited directly PAK1 more strongly than mimosine and mimosinol from leucaena. Cucurbitacin I isolated from bitter gourd/melon also exhibited a moderate anti-PAK1 activity. Hispidin, a metabolite of DK, strongly inhibited PAK1 with the IC50 = 5.7 μM. The IC50 of three hispidin derivatives (H1-3) for PAK1 inhibition ranges from 1.2 to 2.0 μM, while mimosine tetrapeptides [mimosine-Phe-Phe-Tyr (MFFY) and mimosine-Phe-Trp-Tyr (MFWY)] inhibit PAK1 at nanomolar level (IC50 of 0.13 and 0.60 μM, respectively). Thus, we hope these derivatives of hispidin and mimosine could be used as potential leading compounds for developing far more potent anti-PAK1 drugs which would be useful for clinical application in the future. PMID:25639302

  11. Type II p21-activated kinases (PAKs) are regulated by an autoinhibitory pseudosubstrate.

    PubMed

    Ha, Byung Hak; Davis, Matthew J; Chen, Catherine; Lou, Hua Jane; Gao, Jia; Zhang, Rong; Krauthammer, Michael; Halaban, Ruth; Schlessinger, Joseph; Turk, Benjamin E; Boggon, Titus J

    2012-10-01

    The type II p21-activated kinases (PAKs) are key effectors of RHO-family GTPases involved in cell motility, survival, and proliferation. Using a structure-guided approach, we discovered that type II PAKs are regulated by an N-terminal autoinhibitory pseudosubstrate motif centered on a critical proline residue, and that this regulation occurs independently of activation loop phosphorylation. We determined six X-ray crystal structures of either full-length PAK4 or its catalytic domain, that demonstrate the molecular basis for pseudosubstrate binding to the active state with phosphorylated activation loop. We show that full-length PAK4 is constitutively autoinhibited, but mutation of the pseudosubstrate releases this inhibition and causes increased phosphorylation of the apoptotic regulation protein Bcl-2/Bcl-X(L) antagonist causing cell death and cellular morphological changes. We also find that PAK6 is regulated by the pseudosubstrate region, indicating a common type II PAK autoregulatory mechanism. Finally, we find Src SH3, but not β-PIX SH3, can activate PAK4. We provide a unique understanding for type II PAK regulation. PMID:22988085

  12. PAK1 is a breast cancer oncogene that coordinately activates MAPK and MET signaling

    PubMed Central

    Shrestha, Yashaswi; Schafer, Eric J.; Boehm, Jesse S.; Thomas, Sapana R.; He, Frank; Du, Jinyan; Wang, Shumei; Barretina, Jordi; Weir, Barbara A.; Zhao, Jean J.; Polyak, Kornelia; Golub, Todd R.; Beroukhim, Rameen; Hahn, William C.

    2011-01-01

    Activating mutations in the RAS family or BRAF frequently occur in many types of human cancers but are rarely detected in breast tumors. However, activation of the RAS-RAF-MEK-ERK Mitogen-Activated Protein Kinase (MAPK) pathway is commonly observed in human breast cancers, suggesting that other genetic alterations lead to activation of this signaling pathway. To identify breast cancer oncogenes that activate the MAPK pathway, we screened a library of human kinases for their ability to induce anchorage-independent growth in a derivative of immortalized human mammary epithelial cells (HMLE). We identified PAK1 as a kinase that permitted HMLE cells to form anchorage-independent colonies. PAK1 is amplified in several human cancer types, including 33% of breast tumor samples and cancer cell lines. The kinase activity of PAK1 is necessary for PAK1-induced transformation. Moreover, we show that PAK1 simultaneously activates MAPK and MET signaling; the latter via inhibition of Merlin. Disruption of these activities inhibits PAK1-driven anchorage-independent growth. These observations establish PAK1 amplification as an alternative mechanism for MAPK activation in human breast cancer and credential PAK1 as a breast cancer oncogene that coordinately regulates multiple signaling pathways, the cooperation of which leads to malignant transformation. PMID:22105362

  13. P21-activated kinase 4 (PAK4) is required for metaphase spindle positioning and anchoring.

    PubMed

    Bompard, G; Rabeharivelo, G; Cau, J; Abrieu, A; Delsert, C; Morin, N

    2013-02-14

    The oncogenic kinase PAK4 was recently found to be involved in the regulation of the G1 phase and the G2/M transition of the cell cycle. We have also identified that PAK4 regulates Ran GTPase activity during mitosis. Here, we show that after entering mitosis, PAK4-depleted cells maintain a prolonged metaphase-like state. In these cells, chromosome congression to the metaphase plate occurs with normal kinetics but is followed by an extended period during which membrane blebbing and spindle rotation are observed. These bipolar PAK4-depleted metaphase-like spindles have a defective astral microtubule (MT) network and are not centered in the cell but are in close contact with the cell cortex. As the metaphase-like state persists, centrosome fragmentation occurs, chromosomes scatter from the metaphase plate and move toward the spindle poles with an active spindle assembly checkpoint, a phenotype that is reminiscent of cohesion fatigue. PAK4 also regulates the acto-myosin cytoskeleton and we report that PAK4 depletion results in the induction of cortical membrane blebbing during prometaphase arrest. However, we show that membrane blebs, which are strongly enriched in phospho-cofilin, are not responsible for the poor anchoring of the spindle. As PAK4 depletion interferes with the localization of components of the dynein/dynactin complexes at the kinetochores and on the astral MTs, we propose that loss of PAK4 could induce a change in the activities of motor proteins. PMID:22450748

  14. Association with PAK2 Enables Functional Interactions of Lentiviral Nef Proteins with the Exocyst Complex

    PubMed Central

    Imle, Andrea; Abraham, Libin; Tsopoulidis, Nikolaos; Hoflack, Bernard; Saksela, Kalle

    2015-01-01

    ABSTRACT Human immunodeficiency virus type 1 (HIV-1) Nef enhances virus replication and contributes to immune evasion in vivo, but the underlying molecular mechanisms remain incompletely defined. Nef interferes with host cell actin dynamics to restrict T lymphocyte responses to chemokine stimulation and T cell receptor engagement. This relies on the assembly of a labile multiprotein complex including the host kinase PAK2 that Nef usurps to phosphorylate and inactivate the actin-severing factor cofilin. Components of the exocyst complex (EXOC), an octameric protein complex involved in vesicular transport and actin remodeling, were recently reported to interact with Nef via the same molecular surface that mediates PAK2 association. Exploring the functional relevance of EXOC in Nef-PAK2 complex assembly/function, we found Nef-EXOC interactions to be specifically mediated by the PAK2 interface of Nef, to occur in infected human T lymphocytes, and to be conserved among lentiviral Nef proteins. In turn, EXOC was dispensable for direct downstream effector functions of Nef-associated PAK2. Surprisingly, PAK2 was essential for Nef-EXOC association, which required a functional Rac1/Cdc42 binding site but not the catalytic activity of PAK2. EXOC was dispensable for Nef functions in vesicular transport but critical for inhibition of actin remodeling and proximal signaling upon T cell receptor engagement. Thus, Nef exploits PAK2 in a stepwise mechanism in which its kinase activity cooperates with an adaptor function for EXOC to inhibit host cell actin dynamics. PMID:26350970

  15. ERK activation of p21 activated kinase-1 (Pak1) is critical for medulloblastoma cell migration.

    PubMed

    Yuan, Liangping; Santi, Mariarita; Rushing, Elisabeth J; Cornelison, Robert; MacDonald, Tobey J

    2010-10-01

    We previously identified that overexpression of the platelet-derived growth factor receptor (PDGFR) is associated with metastatic medulloblastoma (MB) and showed that PDGF treatment increases ERK activity and promotes MB cell migration. In this study, we investigated whether ERK regulates Rac1/Pak1 signaling and is critically linked to MB cell migration. Herein we demonstrate that PDGF-BB treatment of MB cells induces concomitant activation of PDGFRβ, MEK1/ERK, Rac1 and Pak1, but suppresses Rho activity, which together significantly promotes cell migration. Conversely, cells transfected with either PDGFRβ or Pak1 siRNA or treated with an inhibitor of Rac1 (NSC23766) or N-myristoyltransferase-1 (Tris-dipalladium) are unable to activate Rac1 or Pak1 in response to PDGF, and consequently, are unable to undergo PDGF-mediated cell migration. Furthermore, we also demonstrate that either chemical inhibition of MEK/ERK (U0126) or stable downregulation of PDGFRβ by shRNA similarly results in the loss of PDGF-induced ERK phosphorylation and abolishes Rac1/Pak1 activation and cell migration in response to PDGF. However, specific depletion of Pak1 by siRNA has no effect on PDGF-induced ERK phosphorylation, indicating that in MB cells ERK signaling is Pak1-independent, but PDGF-induced migration is dependent on ERK-mediated activation of Pak1. Finally, using tissue microarrays, we detect phosphorylated Pak1 in 53% of medulloblastomas and show that immunopositivity is associated with unfavorable outcome. We conclude that Rac1/Pak1 signaling is critical to MB cell migration and is functionally dependent on PDGFRβ/ERK activity. PMID:20526801

  16. ERK activation of p21 activated kinase-1 (Pak1) is critical for medulloblastoma cell migration

    PubMed Central

    Yuan, Liangping; Santi, Mariarita; Rushing, Elisabeth J.; Cornelison, Robert

    2010-01-01

    We previously identified that overexpression of the platelet-derived growth factor receptor (PDGFR) is associated with metastatic medulloblastoma (MB) and showed that PDGF treatment increases ERK activity and promotes MB cell migration. In this study, we investigated whether ERK regulates Rac1/Pak1 signaling and is critically linked to MB cell migration. Herein we demonstrate that PDGF-BB treatment of MB cells induces concomitant activation of PDGFRβ, MEK1/ERK, Rac1 and Pak1, but suppresses Rho activity, which together significantly promotes cell migration. Conversely, cells transfected with either PDGFRβ or Pak1 siRNA or treated with an inhibitor of Rac1 (NSC23766) or N-myristoyltransferase-1 (Tris-dipalladium) are unable to activate Rac1 or Pak1 in response to PDGF, and consequently, are unable to undergo PDGF-mediated cell migration. Furthermore, we also demonstrate that either chemical inhibition of MEK/ ERK (U0126) or stable downregulation of PDGFRβ by shRNA similarly results in the loss of PDGF-induced ERK phosphorylation and abolishes Rac1/Pak1 activation and cell migration in response to PDGF. However, specific depletion of Pak1 by siRNA has no effect on PDGF-induced ERK phosphorylation, indicating that in MB cells ERK signaling is Pak1-independent, but PDGF-induced migration is dependent on ERK-mediated activation of Pak1. Finally, using tissue microarrays, we detect phosphorylated Pak1 in 53% of medulloblastomas and show that immunopositivity is associated with unfavorable outcome. We conclude that Rac1/Pak1 signaling is critical to MB cell migration and is functionally dependent on PDGFRβ/ERK activity. PMID:20526801

  17. PAK1 is a therapeutic target in acute myeloid leukemia and myelodysplastic syndrome

    PubMed Central

    Pandolfi, Ashley; Stanley, Robert F.; Yu, Yiting; Bartholdy, Boris; Pendurti, Gopichand; Gritsman, Kira; Boultwood, Jacqueline; Chernoff, Jonathan; Verma, Amit

    2015-01-01

    Poor clinical outcome of acute myeloid leukemia (AML) and myelodysplastic syndrome (MDS) has been attributed to failure of current chemotherapeutic regimens to target leukemic stem cells. We recently identified p21-activated kinase (PAK1) as a downstream effector molecule of H2.0-like homeobox (HLX), a gene functionally relevant for AML pathogenesis. In this study, we find that inhibition of PAK1 activity by small molecule inhibitors or by RNA interference leads to profound leukemia inhibitory effects both in vitro and in vivo. Inhibition of PAK1 induces differentiation and apoptosis of AML cells through downregulation of the MYC oncogene and a core network of MYC target genes. Importantly, we find that inhibition of PAK1 inhibits primary human leukemic cells including immature leukemic stem cell-enriched populations. Moreover, we find that PAK1 upregulation occurs during disease progression and is relevant for patient survival in MDS. Our studies highlight PAK1 as a novel target in AML and MDS and support the use of PAK1 inhibitors as a therapeutic strategy in these diseases. PMID:26170031

  18. An in cellulo-derived structure of PAK4 in complex with its inhibitor Inka1.

    PubMed

    Baskaran, Yohendran; Ang, Khay C; Anekal, Praju V; Chan, Wee L; Grimes, Jonathan M; Manser, Ed; Robinson, Robert C

    2015-01-01

    PAK4 is a metazoan-specific kinase acting downstream of Cdc42. Here we describe the structure of human PAK4 in complex with Inka1, a potent endogenous kinase inhibitor. Using single mammalian cells containing crystals 50 μm in length, we have determined the in cellulo crystal structure at 2.95 Å resolution, which reveals the details of how the PAK4 catalytic domain binds cellular ATP and the Inka1 inhibitor. The crystal lattice consists only of PAK4-PAK4 contacts, which form a hexagonal array with channels of 80 Å in diameter that run the length of the crystal. The crystal accommodates a variety of other proteins when fused to the kinase inhibitor. Inka1-GFP was used to monitor the process crystal formation in living cells. Similar derivatives of Inka1 will allow us to study the effects of PAK4 inhibition in cells and model organisms, to allow better validation of therapeutic agents targeting PAK4. PMID:26607847

  19. An in cellulo-derived structure of PAK4 in complex with its inhibitor Inka1

    PubMed Central

    Baskaran, Yohendran; Ang, Khay C.; Anekal, Praju V.; Chan, Wee L.; Grimes, Jonathan M.; Manser, Ed; Robinson, Robert C.

    2015-01-01

    PAK4 is a metazoan-specific kinase acting downstream of Cdc42. Here we describe the structure of human PAK4 in complex with Inka1, a potent endogenous kinase inhibitor. Using single mammalian cells containing crystals 50 μm in length, we have determined the in cellulo crystal structure at 2.95 Å resolution, which reveals the details of how the PAK4 catalytic domain binds cellular ATP and the Inka1 inhibitor. The crystal lattice consists only of PAK4–PAK4 contacts, which form a hexagonal array with channels of 80 Å in diameter that run the length of the crystal. The crystal accommodates a variety of other proteins when fused to the kinase inhibitor. Inka1–GFP was used to monitor the process crystal formation in living cells. Similar derivatives of Inka1 will allow us to study the effects of PAK4 inhibition in cells and model organisms, to allow better validation of therapeutic agents targeting PAK4. PMID:26607847

  20. p21-activated kinase1 (Pak1) is a negative regulator of NADPH-oxidase 2 in ventricular myocytes

    PubMed Central

    DeSantiago, Jaime; Bare, Dan J; Xiao, Lei; Ke, Yunbo; Solaro, R. John; Banach, Kathrin

    2014-01-01

    Ischemic conditions reduce the activity of the p21-activated kinase (Pak1) resulting in increased arrhythmic activity. Triggered arrhythmic activity during ischemia is based on changes in cellular ionic balance and the cells Ca2+ handling properties. In the current study we used isolated mouse ventricular myocytes (VMs) deficient for the expression of Pak1 (Pak1-/-) to determine the mechanism by which Pak1 influences the generation of arrhythmic activity during simulated ischemia. The Ca2+ transient amplitude and kinetics did not significantly change in wild type (WT) and Pak1-/- VMs during 15 min of simulated ischemia. However, Pak1-/- VMs exhibited an exaggerated increase in [Ca2+]i, which resulted in spontaneous Ca2+ release events and waves. The Ca2+ overload in Pak1-/- VMs could be suppressed with a reverse mode blocker (KB-R7943) of the sodium calcium exchanger (NCX), a cytoplasmic scavenger of reactive oxygen species (ROS; TEMPOL) or a RAC1 inhibitor (NSC23766). Measurements of the cytoplasmic ROS levels revealed that decreased Pak1 activity in Pak1-/- VMs or VMs treated with the Pak1 inhibitor (IPA3) enhanced cellular ROS production. The Pak1 dependent increase in ROS was attenuated in VMs deficient for NADPH oxidase 2 (NOX2; p47phox-/-) or in VMs where NOX2 was inhibited (gp91ds-tat). Voltage clamp recordings showed increased NCX activity in Pak1-/- VMs that depended on enhanced NOX2 induced ROS production. The exaggerated Ca2+ overload in Pak1-/- VMs could be mimicked by low concentrations of ouabain. Overall our data show that Pak1 is a critical negative regulator of NOX2 dependent ROS production and that a latent ROS dependent stimulation of NCX activity can predispose VMs to Ca2+ overload under conditions where no significant changes in excitation-contraction coupling are yet evident. PMID:24380729

  1. Tuning PAK Activity to Rescue Abnormal Myelin Permeability in HNPP.

    PubMed

    Hu, Bo; Arpag, Sezgi; Zhang, Xuebao; Möbius, Wiebke; Werner, Hauke; Sosinsky, Gina; Ellisman, Mark; Zhang, Yang; Hamilton, Audra; Chernoff, Jonathan; Li, Jun

    2016-09-01

    Schwann cells in the peripheral nervous systems extend their membranes to wrap axons concentrically and form the insulating sheath, called myelin. The spaces between layers of myelin are sealed by myelin junctions. This tight insulation enables rapid conduction of electric impulses (action potentials) through axons. Demyelination (stripping off the insulating sheath) has been widely regarded as one of the most important mechanisms altering the action potential propagation in many neurological diseases. However, the effective nerve conduction is also thought to require a proper myelin seal through myelin junctions such as tight junctions and adherens junctions. In the present study, we have demonstrated the disruption of myelin junctions in a mouse model (Pmp22+/-) of hereditary neuropathy with liability to pressure palsies (HNPP) with heterozygous deletion of Pmp22 gene. We observed a robust increase of F-actin in Pmp22+/- nerve regions where myelin junctions were disrupted, leading to increased myelin permeability. These abnormalities were present long before segmental demyelination at the late phase of Pmp22+/- mice. Moreover, the increase of F-actin levels correlated with an enhanced activity of p21-activated kinase (PAK1), a molecule known to regulate actin polymerization. Pharmacological inhibition of PAK normalized levels of F-actin, and completely prevented the progression of the myelin junction disruption and nerve conduction failure in Pmp22+/- mice. Our findings explain how abnormal myelin permeability is caused in HNPP, leading to impaired action potential propagation in the absence of demyelination. We call it "functional demyelination", a novel mechanism upstream to the actual stripping of myelin that is relevant to many demyelinating diseases. This observation also provides a potential therapeutic approach for HNPP. PMID:27583434

  2. Chemically Diverse Group I p21-Activated Kinase (PAK) Inhibitors Impart Acute Cardiovascular Toxicity with a Narrow Therapeutic Window.

    PubMed

    Rudolph, Joachim; Murray, Lesley J; Ndubaku, Chudi O; O'Brien, Thomas; Blackwood, Elizabeth; Wang, Weiru; Aliagas, Ignacio; Gazzard, Lewis; Crawford, James J; Drobnick, Joy; Lee, Wendy; Zhao, Xianrui; Hoeflich, Klaus P; Favor, David A; Dong, Ping; Zhang, Haiming; Heise, Christopher E; Oh, Angela; Ong, Christy C; La, Hank; Chakravarty, Paroma; Chan, Connie; Jakubiak, Diana; Epler, Jennifer; Ramaswamy, Sreemathy; Vega, Roxanne; Cain, Gary; Diaz, Dolores; Zhong, Yu

    2016-06-01

    p21-activated kinase 1 (PAK1) has an important role in transducing signals in several oncogenic pathways. The concept of inhibiting this kinase has garnered significant interest over the past decade, particularly for targeting cancers associated with PAK1 amplification. Animal studies with the selective group I PAK (pan-PAK1, 2, 3) inhibitor G-5555 from the pyrido[2,3-d]pyrimidin-7-one class uncovered acute toxicity with a narrow therapeutic window. To attempt mitigating the toxicity, we introduced significant structural changes, culminating in the discovery of the potent pyridone side chain analogue G-9791. Mouse tolerability studies with this compound, other members of this series, and compounds from two structurally distinct classes revealed persistent toxicity and a correlation of minimum toxic concentrations and PAK1/2 mediated cellular potencies. Broad screening of selected PAK inhibitors revealed PAK1, 2, and 3 as the only overlapping targets. Our data suggest acute cardiovascular toxicity resulting from the inhibition of PAK2, which may be enhanced by PAK1 inhibition, and cautions against continued pursuit of pan-group I PAK inhibitors in drug discovery. PMID:27167326

  3. GIT1/βPIX signaling proteins and PAK1 kinase regulate microtubule nucleation.

    PubMed

    Černohorská, Markéta; Sulimenko, Vadym; Hájková, Zuzana; Sulimenko, Tetyana; Sládková, Vladimíra; Vinopal, Stanislav; Dráberová, Eduarda; Dráber, Pavel

    2016-06-01

    Microtubule nucleation from γ-tubulin complexes, located at the centrosome, is an essential step in the formation of the microtubule cytoskeleton. However, the signaling mechanisms that regulate microtubule nucleation in interphase cells are largely unknown. In this study, we report that γ-tubulin is in complexes containing G protein-coupled receptor kinase-interacting protein 1 (GIT1), p21-activated kinase interacting exchange factor (βPIX), and p21 protein (Cdc42/Rac)-activated kinase 1 (PAK1) in various cell lines. Immunofluorescence microscopy revealed association of GIT1, βPIX and activated PAK1 with centrosomes. Microtubule regrowth experiments showed that depletion of βPIX stimulated microtubule nucleation, while depletion of GIT1 or PAK1 resulted in decreased nucleation in the interphase cells. These data were confirmed for GIT1 and βPIX by phenotypic rescue experiments, and counting of new microtubules emanating from centrosomes during the microtubule regrowth. The importance of PAK1 for microtubule nucleation was corroborated by the inhibition of its kinase activity with IPA-3 inhibitor. GIT1 with PAK1 thus represent positive regulators, and βPIX is a negative regulator of microtubule nucleation from the interphase centrosomes. The regulatory roles of GIT1, βPIX and PAK1 in microtubule nucleation correlated with recruitment of γ-tubulin to the centrosome. Furthermore, in vitro kinase assays showed that GIT1 and βPIX, but not γ-tubulin, serve as substrates for PAK1. Finally, direct interaction of γ-tubulin with the C-terminal domain of βPIX and the N-terminal domain of GIT1, which targets this protein to the centrosome, was determined by pull-down experiments. We propose that GIT1/βPIX signaling proteins with PAK1 kinase represent a novel regulatory mechanism of microtubule nucleation in interphase cells. PMID:27012601

  4. PAK1 is involved in sensing the orientation of collagen stiffness gradients in mouse fibroblasts.

    PubMed

    Pinto, V I; Mohammadi, H; Lee, W S; Cheung, A H; McCulloch, C A

    2015-10-01

    Migrating cells sense variations of stiffness in connective tissue matrices but how cells detect and respond to stiffness orientation is not defined. We examined cell extension formation on collagen with underlying support (vertical stiffness gradient) or on collagen laterally supported by nylon (lateral stiffness gradient). At 6 h after plating, cells plated on laterally-supported collagen exhibited >2-fold more abundant and ~2-fold longer cell extensions than cells plated on collagen with underlying support. We examined whether p21-activated kinase 1 (PAK1) influences extension formation that is dependent on the orientation of support. At 6 h after plating on collagen with underlying support, wild-type cell extensions were 40% shorter than PAK1 knockdown cells. In contrast, on laterally-supported collagen, wild-type cell extensions were 2-fold longer than PAK1 knockdown cells. In cells plated on laterally-supported collagen, there were ~2-fold reductions of collagen fiber alignment and compaction in PAK1 knockdown cells compared with wild-type cells. PAK1 knockdown did not affect collagen fiber alignment or compaction by cells plated on collagen with underlying support. Wild-type cells with lateral support of collagen exhibited 3-fold increases of phospho-myosin staining at 6h, which was 2-fold lower in PAK1 knockdown cells. In contrast, cells on collagen with underlying support showed no increase of phospho-myosin staining at any times. PAK1 knockdown did not affect α2 or β1 integrin expression or function. We conclude that PAK1 is involved in the ability of cells to sense the orientation of stiffness in collagen substrates and generate contractile forces that affect cell extension formation. PMID:26025676

  5. Group I Paks as therapeutic targets in NF2-deficient meningioma

    PubMed Central

    Duron, Sergio G.; Campbell, David A.; Ong, Christy C.; Hoeflich, Klaus P.; Chang, Long-Sheng; Welling, D. Bradley; Yang, Zeng-jie; Chernoff, Jonathan

    2015-01-01

    Neurofibromatosis type 2 (NF2) is an autosomal dominant disorder characterized by the development of multiple tumors in the central nervous system, most notably schwannomas and meningiomas. Mutational inactivation of NF2 is found in 40–60% of sporadic meningiomas, but the molecular mechanisms underlying malignant changes of meningioma cells remain unclear. Because group I p21-activated kinases (Paks) bind to and are inhibited by the NF2-encoded protein Merlin, we assessed the signaling and anti-tumor effects of three group-I specific Pak inhibitors - Frax597, 716 and 1036 - in NF2−/− meningiomas in vitro and in an orthotopic mouse model. We found that these Pak inhibitors suppressed the proliferation and motility of both benign (Ben-Men1) and malignant (KT21-MG1) meningiomas cells. In addition, we found a strong reduction in phosphorylation of Mek and S6, and decreased cyclin D1 expression in both cell lines after treatment with Pak inhibitors. Using intracranial xenografts of luciferase-expressing KT21-MG1 cells, we found that treated mice showed significant tumor suppression for all three Pak inhibitors. Similar effects were observed in Ben-Men1 cells. Tumors dissected from treated animals exhibited an increase in apoptosis without notable change in proliferation. Collectively, these results suggest that Pak inhibitors might be useful agents in treating NF2-deficient meningiomas. PMID:25596744

  6. Artepillin C and Other Herbal PAK1-blockers: Effects on Hair Cell Proliferation and Related PAK1-dependent Biological Function in Cell Culture.

    PubMed

    Nguyen, Binh Cao Quan; Taira, Nozomi; Maruta, Hiroshi; Tawata, Shinkichi

    2016-01-01

    PAK1 (RAC/CDC42-activated kinase 1) is the major oncogenic kinase, and a number of herbal PAK1-blockers such as propolis and curcumin have been shown to be anti-oncogenic and anti-melanogenic as well as anti-alopecia (promoting hair growth). Previously, we found several distinct PAK1-inhibitors in Okinawa plants including Alpinia zerumbet (alpinia). Thus, here, we tested the effects of these herbal compounds and their derivatives on the growth of cancer or normal hair cells, and melanogenesis in cell culture of A549 lung cancer, hair follicle dermal papilla cell, and B16F10 melanoma. Among these herbal PAK1-inhibitors, cucurbitacin I from bitter melon (Goya) turned out to be the most potent to inhibit the growth of human lung cancer cells with the IC50 around 140 nM and to promote the growth of hair cells with the effective dose around 10 nM. Hispidin, a metabolite of 5,6-dehydrokawain from alpinia, inhibited the growth of cancer cells with the IC50 of 25 μM as does artepillin C, the major anti-cancer ingredient in Brazilian green propolis. Mimosine tetrapeptides (MFWY, MFYY, and MFFY) and hispidin derivatives (H1-3) also exhibited a strong anti-cancer activity with the IC50 ranging from 16 to 30 μM. Mimosine tetrapeptides and hispidin derivatives strongly suppressed the melanogenesis in melanoma cells. PMID:26537230

  7. Comparison of the SidePak personal monitor with the Aerosol Particle Sizer (APS).

    PubMed

    Sánchez Jiménez, Araceli; van Tongeren, Martie; Galea, Karen S; Steinsvåg, Kjersti; MacCalman, Laura; Cherrie, John W

    2011-06-01

    The aim of this study was to compare the performance of the TSI Aerodynamic Particle Sizer (APS) and the TSI portable photometer SidePak to measure airborne oil mist particulate matter (PM) with aerodynamic diameters below 10 μm, 2.5 μm and 1 μm (PM(10), PM(2.5) and PM(1)). Three SidePaks each fitted with either a PM(10), PM(2.5) or a PM(1) impactor and an APS were run side by side in a controlled chamber. Oil mist from two different mineral oils and two different drilling fluid systems commonly used in offshore drilling technologies were generated using a nebulizer. Compared to the APS, the SidePaks overestimated the concentration of PM(10) and PM(2.5) by one order of magnitude and PM(1) concentrations by two orders of magnitude after exposure to oil mist for 3.3-6.5 min at concentrations ranging from 0.003 to 18.1 mg m(-3) for PM(10), 0.002 to 3.96 mg m(-3) for PM(2.5) and 0.001 to 0.418 mg m(-3) for PM(1) (as measured by the APS). In a second experiment a SidePak monitor previously exposed to oil mist overestimated PM(10) concentrations by 27% compared to measurements from another SidePak never exposed to oil mist. This could be a result of condensation of oil mist droplets in the optical system of the SidePak. The SidePak is a very useful instrument for personal monitoring in occupational hygiene due to its light weight and quiet pump. However, it may not be suitable for the measurement of particle concentrations from oil mist. PMID:21528134

  8. Synergistic Activation of ERα by Estrogen and Prolactin in Breast Cancer Cells Requires Tyrosyl Phosphorylation of PAK1.

    PubMed

    Oladimeji, Peter; Skerl, Rebekah; Rusch, Courtney; Diakonova, Maria

    2016-05-01

    Serine/threonine kinase PAK1 is activated by estrogen and plays an important role in breast cancer. However, the integration of PAK1 into the estrogen response is not fully understood. In this study, we investigated the mechanisms underlying the hormone-induced activation of estrogen receptor (ERα, ESR1). We show that estrogen activated PAK1 through both the ERα and GPER1 membrane receptors. Estrogen-dependent activation of PAK1 required the phosphorylation of tyrosine residues by Etk/Bmx and protein kinase A (PKA) within an assembled signaling complex comprising pTyr-PAK1, Etk/Bmx, the heterotrimer G-protein subunits Gβ1, Gγ2, and/or Gγ5, PAK-associated guanine nucleotide exchange factor (βPIX, ARHGEF7), and PKA. Moreover, the PKA RIIβ subunit is a direct target of PAK1, and thus in response to estrogen, the activated pTyr-PAK1 complex reciprocally potentiated PKA activity, suggesting a positive feedback mechanism. We also demonstrate that PKA phosphorylated Ser305-ERα in response to estrogen, but pTyr-PAK1 phosphorylated Ser305-ERα in response to prolactin (PRL), implying that maximal ERα phosphorylation is achieved when cells are exposed to both PRL and estrogen. Furthermore, S305-ERα activation led to enhanced phosphorylation of Ser118-ERα and promoted cell proliferation and tumor growth. Together, these data strongly support a critical interplay between PRL and estrogen via PAK1 and suggest that ligand-independent activation of ERα through PRL/PAK1 may impart resistance to anti-estrogen therapies. Cancer Res; 76(9); 2600-11. ©2016 AACR. PMID:26944939

  9. New realism in north Korean propaganda: The death of Pak Chong-ch`ol. Final report

    SciTech Connect

    Shaw, W.

    1987-04-01

    North Korea`s Voice of National Salvation (VNS) broadcasts to South Korea in January and February gave considerable attention to the 13 January 1987 death under police torture of Seoul National University student Pak Chong-ch`ol. VNS commentary emphasized the routine nature of police torture in South Korea and sharply criticized the South Korean Government for blocking attendance at memorial services on 7 February and 3 March. Many VNS comments on the Pak case closely paralleled reactions of the South Korean press and parliamentary opposition, demonstrating close North Korean attention to opinion trends in the South. In a new mood of realism, P`yongyang also used the Pak case to urge South Korean radical students to drop their `avant-gardism`, including excessively leftist slogans and violent tactics that alienate the general populace. P` yongyang clearly wants students to take advantage of issues that have wide public appeal and to broaden resistance to the Chon Tu-hwan Government to include social groups beyond the student population. In P`yongyang`s view, such issues include the Pak case and the signature campaign for constitutional revision in early 1986. If South Korea`s radical students take P`yonyyang`s advice, and if the Republic of Korea Government fails to curb and punish abuses like the Pak killing, this shift in tactics could have significant influence during the coming spring demonstration season.

  10. Pak1 phosphorylation enhances cortactin-N-WASP interaction in clathrin-caveolin-independent endocytosis.

    PubMed

    Grassart, Alexandre; Meas-Yedid, Vannary; Dufour, Alexandre; Olivo-Marin, Jean-Christophe; Dautry-Varsat, Alice; Sauvonnet, Nathalie

    2010-08-01

    Growing evidence indicates that kinases are central to the regulation of endocytic pathways. Previously, we identified p21-activated kinase 1 (Pak1) as the first specific regulator of clathrin- and caveolae-independent endocytosis used by the interleukin 2 receptor subunit (IL-2R). Here, we address the mechanism by which Pak1 regulates IL-2Rbeta endocytosis. First, we show that Pak1 phosphorylates an activator of actin polymerization, cortactin, on its serine residues 405 and 418. Consistently, we observe a specific inhibition of IL-2Rbeta endocytosis when cells overexpress a cortactin, wherein these serine residues have been mutated. In addition, we show that the actin polymerization enhancer, neuronal Wiskott-Aldrich syndrome protein (N-WASP), is involved in IL-2Rbeta endocytosis. Strikingly, we find that Pak1 phosphorylation of cortactin on serine residues 405 and 418 increases its association with N-WASP. Thus, Pak1, by controlling the interaction between cortactin and N-WASP, could regulate the polymerization of actin during clathrin-independent endocytosis. PMID:20444238

  11. Inhibition of Nischarin Expression Promotes Neurite Outgrowth through Regulation of PAK Activity

    PubMed Central

    Ding, Yuemin; Li, Yuying; Lu, Lingchao; Zhang, Ruyi; Zeng, Linghui; Wang, Linlin; Zhang, Xiong

    2015-01-01

    Nischarin is a cytoplasmic protein expressed in various organs that plays an inhibitory role in cell migration and invasion and the carcinogenesis of breast cancer cells. We previously reported that Nischarin is highly expressed in neuronal cell lines and is differentially expressed in the brain tissue of adult rats. However, the physiological function of Nischarin in neural cells remains unknown. Here, we show that Nischarin is expressed in rat primary cortical neurons but not in astrocytes. Nischarin is localized around the nucleus and dendrites. Using shRNA to knockdown the expression of endogenous Nischarin significantly increases the percentage of neurite-bearing cells, remarkably increases neurite length, and accelerates neurite extension in neuronal cells. Silencing Nischarin expression also promotes dendrite elongation in rat cortical neurons where Nischarin interacts with p21-activated kinase 1/2 (PAK1/2) and negatively regulates phosphorylation of both PAK1 and PAK2. The stimulation of neurite growth observed in cells with decreased levels of Nischarin is partially abolished by IPA3-mediated inhibition of PAK1 activity. Our findings indicate that endogenous Nischarin inhibits neurite outgrowth by blocking PAK1 activation in neurons. PMID:26670864

  12. The Cdc42 Effector Kinase PAK4 Localizes to Cell-Cell Junctions and Contributes to Establishing Cell Polarity

    PubMed Central

    Selamat, Widyawilis; Tay, Pei-Ling Felicia; Baskaran, Yohendran; Manser, Ed

    2015-01-01

    The serine/threonine kinase PAK4 is a Cdc42 effector whose role is not well understood; overexpression of PAK4 has been associated with some cancers, and there are reports that correlate kinase level with increased cell migration in vitro. Here we report that PAK4 is primarily associated with cell-cell junctions in all the cell lines we tested, and fails to accumulate at focal adhesions or at the leading edge of migrating cells. In U2OS osteosarcoma and MCF-7 breast cancer cell lines, PAK4 depletion did not affect collective cell migration, but affected cell polarization. By contrast, Cdc42 depletion (as reported by many studies) caused a strong defect in junctional assembly in multiple cells lines. We also report that the depletion of PAK4 protein or treatment of cells with the PAK4 inhibitor PF-3758309 can lead to defects in centrosome reorientation (polarization) after cell monolayer wounding. These experiments are consistent with PAK4 forming part of a conserved cell-cell junctional polarity Cdc42 complex. We also confirm β-catenin as a target for PAK4 in these cells. Treatment of cells with PF-3758309 caused inhibition of β-catenin Ser-675 phosphorylation, which is located predominantly at cell-cell junctions. PMID:26068882

  13. (-)-β-hydrastine suppresses the proliferation and invasion of human lung adenocarcinoma cells by inhibiting PAK4 kinase activity.

    PubMed

    Guo, Bingyu; Li, Xiaodong; Song, Shuai; Chen, Meng; Cheng, Maosheng; Zhao, Dongmei; Li, Feng

    2016-04-01

    (-)-β-hydrastine is one of the main active components of the medicinal plant, Hydrastis canadensis, which is used in many dietary supplements intended to enhance the immune system. However, whether (-)-β-hydrastine affects the tumor signaling pathway remains unexplored. In the present study, we found that (-)-β-hydrastine inhibited the kinase activity of p21-activated kinase 4 (PAK4), which is involved in the regulation of cytoskeletal reorganization, cell proliferation, gene transcription, oncogenic transformation and cell invasion. In the present study, (-)-β-hydrastine suppressed lung adenocarcinoma cell proliferation by inhibiting expression of cyclin D1/D3 and CDK2/4/6, leading to cell cycle arrest at the G1 phase, in a PAK4 kinase-dependent manner. Moreover, inhibition of PAK4 kinase activity by (-)-β-hydrastine also promoted the early apoptosis of lung adenocarcinoma cells through the mitochondrial apoptosis pathway. In addition, (-)-β-hydrastine significantly suppressed the migration and invasion of human lung adenocarcinoma cells in conjunction with concomitant blockage of the PAK4/LIMK1/cofilin, PAK4/SCG10 and PAK4/MMP2 pathways. All of these data indicate that (-)-β-hydrastine, as a novel PAK4 inhibitor, suppresses the proliferation and invasion of lung adenocarcinoma cells. Taken together, these results provide novel insight into the development of a PAK4 kinase inhibitor and a potential therapeutic strategy for lung cancer. PMID:26821251

  14. The Cdc42 Effector Kinase PAK4 Localizes to Cell-Cell Junctions and Contributes to Establishing Cell Polarity.

    PubMed

    Selamat, Widyawilis; Tay, Pei-Ling Felicia; Baskaran, Yohendran; Manser, Ed

    2015-01-01

    The serine/threonine kinase PAK4 is a Cdc42 effector whose role is not well understood; overexpression of PAK4 has been associated with some cancers, and there are reports that correlate kinase level with increased cell migration in vitro. Here we report that PAK4 is primarily associated with cell-cell junctions in all the cell lines we tested, and fails to accumulate at focal adhesions or at the leading edge of migrating cells. In U2OS osteosarcoma and MCF-7 breast cancer cell lines, PAK4 depletion did not affect collective cell migration, but affected cell polarization. By contrast, Cdc42 depletion (as reported by many studies) caused a strong defect in junctional assembly in multiple cells lines. We also report that the depletion of PAK4 protein or treatment of cells with the PAK4 inhibitor PF-3758309 can lead to defects in centrosome reorientation (polarization) after cell monolayer wounding. These experiments are consistent with PAK4 forming part of a conserved cell-cell junctional polarity Cdc42 complex. We also confirm β-catenin as a target for PAK4 in these cells. Treatment of cells with PF-3758309 caused inhibition of β-catenin Ser-675 phosphorylation, which is located predominantly at cell-cell junctions. PMID:26068882

  15. Fission yeast pak1+ encodes a protein kinase that interacts with Cdc42p and is involved in the control of cell polarity and mating.

    PubMed Central

    Ottilie, S; Miller, P J; Johnson, D I; Creasy, C L; Sells, M A; Bagrodia, S; Forsburg, S L; Chernoff, J

    1995-01-01

    A STE20/p65pak homolog was isolated from fission yeast by PCR. The pak1+ gene encodes a 72 kDa protein containing a putative p21-binding domain near its amino-terminus and a serine/threonine kinase domain near its carboxyl-terminus. The Pak1 protein autophosphorylates on serine residues and preferentially binds to activated Cdc42p both in vitro and in vivo. This binding is mediated through the p21 binding domain on Pak1p and the effector domain on Cdc42p. Overexpression of an inactive mutant form of pak1 gives rise to cells with markedly abnormal shape with mislocalized actin staining. Pak1 overexpression does not, however, suppress lethality associated with cdc42-null cells or the morphologic defeat caused by overexpression of mutant cdc42 alleles. Gene disruption of pak1+ establishes that, like cdc42+, pak1+ function is required for cell viability. In budding yeast, pak1+ expression restores mating function to STE20-null cells and, in fission yeast, overexpression of an inactive form of Pak inhibits mating. These results indicate that the Pak1 protein is likely to be an effector for Cdc42p or a related GTPase, and suggest that Pak1p is involved in the maintenance of cell polarity and in mating. Images PMID:8846783

  16. GL-1196 Suppresses the Proliferation and Invasion of Gastric Cancer Cells via Targeting PAK4 and Inhibiting PAK4-Mediated Signaling Pathways

    PubMed Central

    Zhang, Jian; Zhang, Hong-Yan; Wang, Jian; You, Liang-Hao; Zhou, Rui-Zhi; Zhao, Dong-Mei; Cheng, Mao-Sheng; Li, Feng

    2016-01-01

    Gastric cancer, which is the most common malignant gastrointestinal tumor, has jumped to the third leading cause of cancer-related mortality worldwide. It is of great importance to identify novel and potent drugs for gastric cancer treatment. P21-activated kinase 4 (PAK4) has emerged as an attractive target for the development of anticancer drugs in consideration of its vital functions in tumorigenesis and progression. In this paper, we reported that GL-1196, as a small molecular compound, effectively suppressed the proliferation of human gastric cancer cells through downregulation of PAK4/c-Src/EGFR/cyclinD1 pathway and CDK4/6 expression. Moreover, GL-1196 prominently inhibited the invasion of human gastric cancer cells in parallel with blockage of the PAK4/LIMK1/cofilin pathway. Interestingly, GL-1196 also inhibited the formation of filopodia and induced cell elongation in SGC7901 and BGC823 cells. Taken together, these results provided novel insights into the potential therapeutic strategy for gastric cancer. PMID:27077843

  17. Group I p21-Activated Kinases (PAKs) Promote Tumor Cell Proliferation and Survival Through the AKT1 and Raf-MAPK Pathways

    PubMed Central

    Menges, Craig W.; Sementino, Eleonora; Talarchek, Jacqueline; Xu, Jinfei; Chernoff, Jonathan; Peterson, Jeffrey R.; Testa, Joseph R.

    2012-01-01

    Group I p21-activated kinases (PAKs) are important effectors of the small GTPases Rac and Cdc42, which regulate cell motility/migration, survival, proliferation and gene transcription. Hyperactivation of these kinases have been reported in many tumor types, making PAKs attractive targets for therapeutic intervention. PAKs are activated by growth factor-mediated signaling and are negatively regulated by the tumor suppressor NF2/Merlin. Thus, tumors characterized by NF2 inactivation would be expected to show hyperactivated PAK signaling. Based on this rationale, we evaluated the status of PAK signaling in malignant mesothelioma (MM), an aggressive neoplasm that is resistant to current therapies and shows frequent inactivation of NF2. We demonstrate that group I PAKs are activated in most MMs and MM cell lines and that genetic or pharmacological inhibition of PAKs is sufficient to inhibit MM cell proliferation and survival. We also identify downstream effectors and signaling pathways that may contribute mechanistically to PAK-related tumorigenesis. Specifically, we show that inhibition of PAK results in attenuation of AKT and Raf-MAPK signaling and decreased tumor cell viability. Collectively, these data suggest that pharmacological inhibition of group I PAKs may have therapeutic efficacy in tumors characterized by PAK activation. PMID:22798428

  18. Pak1 Regulates the Orientation of Apical Polarization and Lumen Formation by Distinct Pathways

    PubMed Central

    Smits, Jos; ter Beest, Martin B.; Zegers, Mirjam M.

    2012-01-01

    The development of the basic architecture of branching tubules enclosing a central lumen that characterizes most epithelial organs crucially depends on the apico-basolateral polarization of epithelial cells. Signals from the extracellular matrix control the orientation of the apical surface, so that it faces the lumen interior, opposite to cell-matrix adhesion sites. This orientation of the apical surface is thought to be intrinsically linked to the formation of single lumens. We previously demonstrated in three-dimensional cyst cultures of Madin-Darby canine kidney (MDCK) cells that signaling by β1 integrins regulates the orientation of the apical surface, via a mechanism that depends on the activity of the small GTPase Rac1. Here, we investigated whether the Rac1 effector Pak1 is a downstream effector in this pathway. Expression of constitutive active Pak1 phenocopies the effect of β1 integrin inhibition in that it misorients the apical surface and induces a multilumen phenotype. The misorientation of apical surfaces depends on the interaction of active Pak1 with PIX proteins and is linked to defects in basement membrane assembly. In contrast, the multilumen phenotype was independent of PIX and the basement membrane. Therefore, Pak1 likely regulates apical polarization and lumen formation by two distinct pathways. PMID:22815903

  19. Regulation of AMPA receptor subunit GluA1 surface expression by PAK3 phosphorylation

    PubMed Central

    Hussain, Natasha K.; Thomas, Gareth M.; Luo, Junjie; Huganir, Richard L.

    2015-01-01

    AMPA receptors (AMPARs) are the major excitatory receptors of the brain and are fundamental to synaptic plasticity, memory, and cognition. Dynamic recycling of AMPARs in neurons is regulated through several types of posttranslational modification, including phosphorylation. Here, we identify a previously unidentified signal transduction cascade that modulates phosphorylation of serine residue 863 (S863) in the GluA1 AMPAR subunit and controls surface trafficking of GluA1 in neurons. Activation of the EphR–Ephrin signal transduction pathway enhances S863 phosphorylation. Further, EphB2 can interact with Zizimin1, a guanine–nucleotide exchange factor that activates Cdc42 and stimulates S863 phosphorylation in neurons. Among the numerous targets downstream of Cdc42, we determined that the p21-activated kinase-3 (PAK3) phosphorylates S863 in vitro. Moreover, specific loss of PAK3 expression and pharmacological inhibition of PAK both disrupt activity-dependent phosphorylation of S863 in cortical neurons. EphB2, Cdc42, and PAKs are broadly capable of controlling dendritic spine formation and synaptic plasticity and are implicated in multiple cognitive disorders. Collectively, these data delineate a novel signal cascade regulating AMPAR trafficking that may contribute to the molecular mechanisms that govern learning and cognition. PMID:26460013

  20. Decontamination of the Shaft no.1 and cleaning container of 2. block NPP Paks

    SciTech Connect

    Bolcha, Jan; Mala, Zuzana; Tilky, Peter

    2007-07-01

    Available in abstract form only. Full text of publication follows: Meanwhile cleaning fuel assemblies on Paks NPP Unit 2. in 2003 year, the fuel assemblies were damaged, followed by contamination of cleaning container and operating shaft No. 1., in which was the container. As a part of the task - to restore operation NPP Paks, Unit 2, VUJE and.. realized decontamination of the wall of shaft prior to withdrawal of the defected fuel, decontamination of cleaning tank and in consequence decontamination of full shaft No. 1. Solution rest at finished conceptual decontamination proposal, fabrication of special purpose furnished, necessary documentation according to national legislative exigency. Real facilities on decontamination were examined on the stand and on shaft No. 1 in real conditions. This paper describes access method decontaminating procedure, applied facilities assigned on decontamination and present achievement results from decontamination shaft No. 1 realized in August 2006 and February 2007, respectively. Decontamination procedures were chosen on the base of experiments realized in laboratories VUJE and in Paks NPP. Laboratory experiments were realized on the sample of tube used for measurement of neutron flow, from NPP Paks, located in the shaft No.1 in time of event (INES-3). In NPP Paks were realized experiments on cover of cleaning container, which was in time of event situated on cleaning container. To compare decontaminated factors, the chemical and electrochemical procedures for decontamination were tested, and most effective practices were selected. Equipment ROS-740 can be used for the top part of the shaft decontamination. It allows high-pressure admission, rinse and chemical decontamination. Manipulator MAOS-170 is assigned for high-pressure admission of central part of the shaft. (authors)

  1. PAK6 increase chemoresistance and is a prognostic marker for stage II and III colon cancer patients undergoing 5-FU based chemotherapy

    PubMed Central

    Yan, Dongwang; Cui, Feifei; Wang, Xiaoliang; Yu, Fudong; Xue, Yingming; Feng, Xiaodong; Wang, Jingtao; Wang, Xiao; Jiang, Tao; Zhang, Meng; Zhao, Senlin; Yu, Yang; Tang, Huamei; Peng, Zhihai

    2015-01-01

    p21-Activated kinase 6 (PAK6) has been implicated in radiotherapy and docetaxel resistance. We have further evaluated PAK6 as a predictor of 5-fluorouracil (5-FU) treatment response in colon cancer. Here we report that in colon cancer PAK6 promotes tumor progression and chemoresistance both in vitro and in vivo. In the clinical analysis, PAK6 was overexpressed in 104 of 147 (70.75%) stage II and III patients who received 5-FU based chemotherapy after surgery. Multivariate Cox regression analysis indicated that PAK6 was an independent prognostic factor for overall survival (P < 0.001) and disease-free survival (P < 0.001). Colon cancer cell lines showed increased PAK6 expression upon 5-FU treatment. In PAK6-knockdown cells treated with 5-FU, cell viability and phosphorylation of BAD decreased, and the number of apoptotic cells, levels of cleaved caspase 3 and PARP increased compared to control cells. The opposite was observed in PAK6 overexpressing cells. Short hairpin RNA knockdown of PAK6 blocked cells in G2-M phase. Furthermore, Animal experiments results in vivo are consistent with outcomes in vitro. This study demonstrates that PAK6 is an independent prognostic factor for adjuvant 5-FU-based chemotherapy in patients with stage II and stage III colon cancer. PMID:25426562

  2. miR-129 suppresses tumor cell growth and invasion by targeting PAK5 in hepatocellular carcinoma

    SciTech Connect

    Zhai, Jian; Qu, Shuping; Li, Xiaowei; Zhong, Jiaming; Chen, Xiaoxia; Qu, Zengqiang; Wu, Dong

    2015-08-14

    Emerging evidence suggests that microRNAs (miRNAs) play important roles in regulating HCC development and progression; however, the mechanisms by which their specific functions and mechanisms remained to be further explored. miR-129 has been reported in gastric cancers, lung cancer and colon cancer. In this study, we disclosed a new tumor suppresser function of miR-129 in HCC. We also found the downregulation of miR-129 occurred in nearly 3/4 of the tumors examined (56/76) compared with adjacent nontumorous tissues, which was more importantly, correlated to the advanced stage and vascular invasion. We then demonstrated that miR-129 overexpression attenuated HCC cells proliferation and invasion, inducing apoptosis in vitro. Moreover, we used miR-129 antagonist and found that anti-miR-129 promoted HCC cells malignant phenotypes. Mechanistically, our further investigations revealed that miR-129 suppressed cell proliferation and invasion by targeting the 3’-untranslated region of PAK5, as well as miR-129 silencing up-regulated PAK5 expression. Moreover, miR-129 expression was inversely correlated with PAK5 expression in 76 cases of HCC samples. RNA interference of PAK5 attenuated anti-miR-129 mediated cell proliferation and invasion in HCC cells. Taken together, these results demonstrated that miR-129 suppressed tumorigenesis and progression by directly targeting PAK5, defining miR-129 as a potential treatment target for HCC. - Highlights: • Decreased of miR-129 is found in HCC and associated with advanced stage and metastasis. • miR-129 suppresses proliferation and invasion of HCC cells. • miR-129 directly targets the 3′ UTR of PAK5 and diminishes PAK5 expression. • PAK5 is involved in miR-129 mediated suppression functions.

  3. P21-activated protein kinase (PAK2)-mediated c-Jun phosphorylation at 5 threonine sites promotes cell transformation

    PubMed Central

    Li, Tingting; Zhang, Jishuai; Zhu, Feng; Wen, Weihong; Zykova, Tatyana; Li, Xiang; Liu, Kangdong; Peng, Cong; Ma, Weiya; Shi, Guozheng; Dong, Ziming; Bode, Ann M.; Dong, Zigang

    2011-01-01

    The oncoprotein c-Jun is one of the components of the activator protein-1 (AP-1) transcription factor complex. AP-1 regulates the expression of many genes and is involved in a variety of biological functions such as cell transformation, proliferation, differentiation and apoptosis. AP-1 activates a variety of tumor-related genes and therefore promotes tumorigenesis and malignant transformation. Here, we found that epidermal growth factor (EGF) induces phosphorylation of c-Jun by P21-activated kinase (PAK) 2. Our data showed that PAK2 binds and phosphorylates c-Jun at five threonine sites (Thr2, Thr8, Thr89, Thr93 and Thr286) in vitro and ex vivo. Knockdown of PAK2 in JB6 Cl41 (P+) cells had no effect on c-Jun phosphorylation at Ser63 or Ser73 but resulted in decreases in EGF-induced anchorage-independent cell transformation, proliferation and AP-1 activity. Mutation at all five c-Jun threonine sites phosphorylated by PAK2 decreased the transforming ability of JB6 cells. Knockdown of PAK2 in SK-MEL-5 melanoma cells also decreased colony formation, proliferation and AP-1 activity. These results indicated that PAK2/c-Jun signaling plays an important role in EGF-induced cell proliferation and transformation. PMID:21177766

  4. The Dynamic Growth Exhibition and Accumulation of Cadmium of Pak Choi (Brassica campestris L. ssp. chinensis) Grown in Contaminated Soils

    PubMed Central

    Lai, Hung-Yu; Chen, Bo-Ching

    2013-01-01

    The accumulation of heavy metals, especially cadmium (Cd), in leafy vegetables was compared with other vegetables. Pak choi (Brassica campestris L. ssp. chinensis) is a leafy vegetable consumed in Taiwan and its safety for consumption after growing in contaminated soils is a public concern. A pot experiment (50 days) was conducted to understand the dynamic accumulation of Cd by pak choi grown in artificially contaminated soils. The edible parts of pak choi were sampled and analyzed every 2–3 days. The dry weight (DW) of pak choi was an exponential function of leaf length, leaf width, and chlorophyll content. The accumulation of Cd increased when the soil Cd concentration was raised, but was kept at a constant level during different growth stages. Pak choi had a high bioconcentration factor (BCF = ratio of the concentration in the edible parts to that in the soils), at values of 3.5–4.0. The consumption of pak choi grown in soils contaminated at levels used in this study would result in the ingestion of impermissible amounts of Cd and could possibly have harmful effects on health. PMID:24284350

  5. Bistability in the Rac1, PAK, and RhoA Signaling Network Drives Actin Cytoskeleton Dynamics and Cell Motility Switches

    PubMed Central

    Byrne, Kate M.; Monsefi, Naser; Dawson, John C.; Degasperi, Andrea; Bukowski-Wills, Jimi-Carlo; Volinsky, Natalia; Dobrzyński, Maciej; Birtwistle, Marc R.; Tsyganov, Mikhail A.; Kiyatkin, Anatoly; Kida, Katarzyna; Finch, Andrew J.; Carragher, Neil O.; Kolch, Walter; Nguyen, Lan K.; von Kriegsheim, Alex; Kholodenko, Boris N.

    2016-01-01

    Summary Dynamic interactions between RhoA and Rac1, members of the Rho small GTPase family, play a vital role in the control of cell migration. Using predictive mathematical modeling, mass spectrometry-based quantitation of network components, and experimental validation in MDA-MB-231 mesenchymal breast cancer cells, we show that a network containing Rac1, RhoA, and PAK family kinases can produce bistable, switch-like responses to a graded PAK inhibition. Using a small chemical inhibitor of PAK, we demonstrate that cellular RhoA and Rac1 activation levels respond in a history-dependent, bistable manner to PAK inhibition. Consequently, we show that downstream signaling, actin dynamics, and cell migration also behave in a bistable fashion, displaying switches and hysteresis in response to PAK inhibition. Our results demonstrate that PAK is a critical component in the Rac1-RhoA inhibitory crosstalk that governs bistable GTPase activity, cell morphology, and cell migration switches. PMID:27136688

  6. Bistability in the Rac1, PAK, and RhoA Signaling Network Drives Actin Cytoskeleton Dynamics and Cell Motility Switches.

    PubMed

    Byrne, Kate M; Monsefi, Naser; Dawson, John C; Degasperi, Andrea; Bukowski-Wills, Jimi-Carlo; Volinsky, Natalia; Dobrzyński, Maciej; Birtwistle, Marc R; Tsyganov, Mikhail A; Kiyatkin, Anatoly; Kida, Katarzyna; Finch, Andrew J; Carragher, Neil O; Kolch, Walter; Nguyen, Lan K; von Kriegsheim, Alex; Kholodenko, Boris N

    2016-01-27

    Dynamic interactions between RhoA and Rac1, members of the Rho small GTPase family, play a vital role in the control of cell migration. Using predictive mathematical modeling, mass spectrometry-based quantitation of network components, and experimental validation in MDA-MB-231 mesenchymal breast cancer cells, we show that a network containing Rac1, RhoA, and PAK family kinases can produce bistable, switch-like responses to a graded PAK inhibition. Using a small chemical inhibitor of PAK, we demonstrate that cellular RhoA and Rac1 activation levels respond in a history-dependent, bistable manner to PAK inhibition. Consequently, we show that downstream signaling, actin dynamics, and cell migration also behave in a bistable fashion, displaying switches and hysteresis in response to PAK inhibition. Our results demonstrate that PAK is a critical component in the Rac1-RhoA inhibitory crosstalk that governs bistable GTPase activity, cell morphology, and cell migration switches. PMID:27136688

  7. Effect of Okinawa Propolis on PAK1 Activity, Caenorhabditis elegans Longevity, Melanogenesis, and Growth of Cancer Cells.

    PubMed

    Taira, Nozomi; Nguyen, Binh Cao Quan; Be Tu, Pham Thi; Tawata, Shinkichi

    2016-07-13

    Propolis from different areas has been reported to inhibit oncogenic/aging kinase PAK1, which is responsible for a variety of conditions, including cancer, longevity, and melanogenesis. Here, a crude extract of Okinawa propolis (OP) was tested against PAK1 activity, Caenorhabditis elegans (C. elegans) longevity, melanogenesis, and growth of cancer cells. We found that OP blocks PAK1 and exhibits anticancer activity in the A549 cell (human lung cancer cell) line with IC50 values of 6 μg/mL and 12 μg/mL, respectively. Most interestingly, OP (1 μg/mL) significantly reduces reproduction and prolongs the lifespan of C. elegans by activating the HSP-16.2 gene, as shown in the PAK1-deficient strain. Furthermore, OP inhibits melanogenesis in a melanoma cell line (B16F10) by downregulating intracellular tyrosinase activity with an IC50 of 30 μg/mL. Our results suggest that OP demonstrated a life span extending effect, C. elegans, anticancer, and antimelanogenic effects via PAK1 inactivation; therefore, this can be a potent natural medicinal supplement against PAK1-dependent diseases. PMID:27337169

  8. Actin cytoskeleton organization regulated by the PAK family of protein kinases.

    PubMed

    Eby, J J; Holly, S P; van Drogen, F; Grishin, A V; Peter, M; Drubin, D G; Blumer, K J

    1998-08-27

    Cdc42, Rac1 and other Rho-type GTPases regulate gene expression, cell proliferation and cytoskeletal architecture [1,2]. A challenge is to identify the effectors of Cdc42 and Rac1 that mediate these biological responses. Protein kinases of the p21-activated kinase (PAK) family bind activated Rac1 and Cdc42, and switch on mitogen-activated protein (MAP) kinase pathways; however, their roles in regulating actin cytoskeleton organization have not been clearly established [3-5]. Here, we show that mutants of the budding yeast Saccharomyces cerevisiae lacking the PAK homologs Ste20 and Cla4 exhibit actin cytoskeletal defects, in vivo and in vitro, that resemble those of cdc42-1 mutants. Moreover, STE20 overexpression suppresses cdc42-1 growth defects and cytoskeletal defects in vivo, and Ste20 kinase corrects the actin-assembly defects of permeabilized cdc42-1 cells in vitro. Thus, PAKs are effectors of Cdc42 in pathways that regulate the organization of the cortical actin cytoskeleton. PMID:9742399

  9. The p21-activated kinase, PAK2, is important in the activation of numerous pancreatic acinar cell signaling cascades and in the onset of early pancreatitis events.

    PubMed

    Nuche-Berenguer, Bernardo; Ramos-Álvarez, Irene; Jensen, R T

    2016-06-01

    In a recent study we explored Group-1-p21-activated kinases (GP.1-PAKs) in rat pancreatic acini. Only PAK2 was present; it was activated by gastrointestinal-hormones/neurotransmitters and growth factors in a PKC-, Src- and small-GTPase-mediated manner. PAK2 was required for enzyme-secretion and ERK/1-2-activation. In the present study we examined PAK2's role in CCK and TPA-activation of important distal signaling cascades mediating their physiological/pathophysiological effects and analyzed its role in pathophysiological processes important in early pancreatitis. In rat pancreatic acini, PAK2-inhibition by the specific, GP.1.PAK-inhibitor, IPA-3-suppressed cholecystokinin (CCK)/TPA-stimulated activation of focal-adhesion kinases and mitogen-activated protein-kinases. PAK2-inhibition reversed the dual stimulatory/inhibitory effect of CCK/TPA on the PI3K/Akt/GSK-3β pathway. However, its inhibition did not affect PKC activation. PAK2-inhibition protected acini from CCK-induced ROS-generation; caspase/trypsin-activation, important in early pancreatitis; as well as from cell-necrosis. Furthermore, PAK2-inhibition reduced proteolytic-activation of PAK-2p34, which is involved in programmed-cell-death. To ensure that the study did not only rely in the specificity of IPA-3 as a PAK inhibitor, we used two other approaches for PAK inhibition, FRAX597 a ATP-competitive-GP.1-PAKs-inhibitor and infection with a PAK2-dominant negative(DN)-Advirus. Those two approaches confirmed the results obtained with IPA-3. This study demonstrates that PAK2 is important in mediating CCK's effect on the activation of signaling-pathways known to mediate its physiological/pathophysiological responses including several cellular processes linked to the onset of pancreatitis. Our results suggest that PAK2 could be a new, important therapeutic target to consider for the treatment of diseases involving deregulation of pancreatic acinar cells. PMID:26912410

  10. Pak1, adjuvant tamoxifen therapy, and breast cancer recurrence risk in a Danish population-based study.

    PubMed

    Ahern, Thomas P; Cronin-Fenton, Deirdre P; Lash, Timothy L; Sørensen, Henrik Toft; Ording, Anne Gulbech; Hamilton-Dutoit, Stephen J; Hellberg, Ylva

    2016-06-01

    Background Adjuvant tamoxifen therapy approximately halves the risk of estrogen receptor-positive (ER+) breast cancer recurrence, but many women do not respond to therapy. Observational studies nested in clinical trial populations suggest that overexpression or nuclear localization of p21-activated kinase 1 (Pak1) in primary tumors predicts tamoxifen failure. Material and methods We measured the association between Pak1 expression and breast cancer recurrence in a Danish population-based case-control study. Pak1 cytoplasmic expression level and nuclear positivity were determined by immunohistochemical staining of primary breast tumors from recurrence cases and matched controls from two breast cancer populations; women diagnosed with ER-positive tumors who received at least one year of tamoxifen therapy (ER+/TAM+), and women diagnosed with ER-negative tumors who survived for at least one year (ER-/TAM-). Pak1 staining was assessed by a single, blinded pathologist, and associations were estimated with conditional logistic regression models. Results We included 541 recurrence cases and 1:1 matched controls from the ER+/TAM + group and 300 recurrence cases and 1:1 matched controls from the ER-/TAM - group. Pak1 cytoplasmic intensity was not associated with breast cancer recurrence in either group (ER+/TAM + ORadj for strong vs. no cytoplasmic staining = 0.91, 95% CI 0.57, 1.5; ER-/TAM - ORadj for strong vs. no cytoplasmic staining = 0.74, 95% CI 0.39, 1.4). Associations between Pak1 nuclear positivity and breast cancer recurrence were similarly near null in both groups. Conclusion Pak1 positivity in primary breast tumors was neither predictive nor prognostic in this prospective, population-based study. PMID:27056567

  11. A Mutation in Mouse Pak1ip1 Causes Orofacial Clefting while Human PAK1IP1 Maps to 6p24 Translocation Breaking Points Associated with Orofacial Clefting

    PubMed Central

    Helminski, Simon; Sturm, Richard; Maute, Roy L.; May, Scott R.; Hozyasz, Kamil K.; Wójcicki, Piotr; Mostowska, Adrianna; Davidson, Beth; Adamopoulos, Iannis E.; Pleasure, Samuel J.; Murray, Jeffrey C.; Zarbalis, Konstantinos S.

    2013-01-01

    Orofacial clefts are among the most common birth defects and result in an improper formation of the mouth or the roof of the mouth. Monosomy of the distal aspect of human chromosome 6p has been recognized as causative in congenital malformations affecting the brain and cranial skeleton including orofacial clefts. Among the genes located in this region is PAK1IP1, which encodes a nucleolar factor involved in ribosomal stress response. Here, we report the identification of a novel mouse line that carries a point mutation in the Pak1ip1 gene. Homozygous mutants show severe developmental defects of the brain and craniofacial skeleton, including a median orofacial cleft. We recovered this line of mice in a forward genetic screen and named the allele manta-ray (mray). Our findings prompted us to examine human cases of orofacial clefting for mutations in the PAK1IP1 gene or association with the locus. No deleterious variants in the PAK1IP1 gene coding region were recognized, however, we identified a borderline association effect for SNP rs494723 suggesting a possible role for the PAK1IP1 gene in human orofacial clefting. PMID:23935987

  12. Combination of immunoprecipitation (IP)-ATP_Glo kinase assay and melanogenesis for the assessment of potent and safe PAK1-blockers in cell culture.

    PubMed

    Nguyen, Binh Cao Quan; Be Tu, Pham Thi; Tawata, Shinkichi; Maruta, Hiroshi

    2015-08-01

    Cucurbitacin I (CBI) is a triterpene from a bitter melon called Goya grown in Okinawa, Japan, and directly inhibits both the Tyr-kinase JAK2 and the G protein RAC, leading to the inactivation of PAK1 (RAC/CDC42-activated kinase 1). Bio 30, a propolis produced in New Zealand, contains CAPE (caffeic acid phenethyl ester) as the major anti-cancer ingredient which directly down-regulates RAC, leading to the inactivation of PAK1. Since PAK1 is essential for the growth of RAS cancer cells such as A549 cell line which carry an oncogenic K-RAS mutant, and the melanogenesis in skin cells, here using these PAK1-blockers as model compounds, we introduce a new approach to the quick assessment of PAK1-blockers in cell culture. First, combining the immuno-precipitation (IP) of PAK1 from cell lysate and the in vitro ATP_Glo kinase assay kit (called "Macaroni-Western" assay), we confirmed that both CBI and Bio 30 inactivate PAK1 in A549 lung cancer cells in 24 h, and inhibit their PAK1-dependent growth in 72 h. Furthermore, we verified that CBI inhibits the PAK1/PAK4-dependent melanogenesis in melanoma cells by far more than 50%, while Bio 30 inhibits the melanogenesis only by 50%, with only a merginal effect on their growth per se. Since the "Macaroni-Western" kinase assay and melanogenesis are both rather simple and quick, the combination of these two cell culture assays would be highly useful for selecting both "potent" (highly cell-permeable) and "safe" (non-toxic) natural or synthetic PAK1-blockers. PMID:26370527

  13. Pak2 Controls Acquisition of NKT Cell Fate by Regulating Expression of the Transcription Factors PLZF and Egr2.

    PubMed

    O'Hagan, Kyle L; Zhao, Jie; Pryshchep, Olga; Wang, Chyung-Ru; Phee, Hyewon

    2015-12-01

    NKT cells constitute a small population of T cells developed in the thymus that produce large amounts of cytokines and chemokines in response to lipid Ags. Signaling through the Vα14-Jα18 TCR instructs commitment to the NKT cell lineage, but the precise signaling mechanisms that instruct their lineage choice are unclear. In this article, we report that the cytoskeletal remodeling protein, p21-activated kinase 2 (Pak2), was essential for NKT cell development. Loss of Pak2 in T cells reduced stage III NKT cells in the thymus and periphery. Among different NKT cell subsets, Pak2 was necessary for the generation and function of NKT1 and NKT2 cells, but not NKT17 cells. Mechanistically, expression of Egr2 and promyelocytic leukemia zinc finger (PLZF), two key transcription factors for acquiring the NKT cell fate, were markedly diminished in the absence of Pak2. Diminished expression of Egr2 and PLZF were not caused by aberrant TCR signaling, as determined using a Nur77-GFP reporter, but were likely due to impaired induction and maintenance of signaling lymphocyte activation molecule 6 expression, a TCR costimulatory receptor required for NKT cell development. These data suggest that Pak2 controls thymic NKT cell development by providing a signal that links Egr2 to induce PLZF, in part by regulating signaling lymphocyte activation molecule 6 expression. PMID:26519537

  14. PAK1IP1, a ribosomal stress-induced nucleolar protein, regulates cell proliferation via the p53–MDM2 loop

    PubMed Central

    Yu, Weishi; Qiu, Zhongwei; Gao, Na; Wang, Liren; Cui, Hengxiang; Qian, Yu; Jiang, Li; Luo, Jian; Yi, Zhengfang; Lu, Hua; Li, Dali; Liu, Mingyao

    2011-01-01

    Cell growth and proliferation are tightly controlled via the regulation of the p53–MDM2 feedback loop in response to various cellular stresses. In this study, we identified a nucleolar protein called PAK1IP1 as another regulator of this loop. PAK1IP1 was induced when cells were treated with chemicals that disturb ribosome biogenesis. Overexpression of PAK1IP1 inhibited cell proliferation by inducing p53-dependent G1 cell-cycle arrest. PAK1IP1 bound to MDM2 and inhibited its ability to ubiquitinate and to degrade p53, consequently leading to the accumulation of p53 levels. Interestingly, knockdown of PAK1IP1 in cells also inhibited cell proliferation and induced p53-dependent G1 arrest. Deficiency of PAK1IP1 increased free ribosomal protein L5 and L11 which were required for PAK1IP1 depletion-induced p53 activation. Taken together, our results reveal that PAK1IP1 is a new nucleolar protein that is crucial for rRNA processing and plays a regulatory role in cell proliferation via the p53–MDM2 loop. PMID:21097889

  15. Improvement of insulin signaling in myoblast cells by an addition of SKIP-binding peptide within Pak1 kinase domain.

    PubMed

    Ijuin, Takeshi; Takenawa, Tadaomi

    2015-01-01

    Abnormalities in insulin-induced glucose incorporation in skeletal muscle were observed in Type 2 diabetes. Our previous studies revealed that the binding between skeletal muscle and kidney-enriched inositol polyphosphate phosphatase (SKIP) and p21-activated protein kinase (Pak1) at the plasma membrane is induced insulin-dependently and that this binding mediated a rapid and efficient termination of insulin signaling and a subsequent glucose uptake into skeletal muscle cells. Here, we identified 11-amino-acids peptide within kinase domain of Pak1, necessary and sufficient for SKIP binding. Expression of this region in C2C12 cells resulted in an increase in insulin signaling. Supplementation of a synthetic peptide of this sequence increased insulin signaling and insulin-induced glucose uptake into skeletal muscle cell lines. These findings suggest the physiological role of Pak1-SKIP binding in the regulation of insulin signaling in skeletal muscle. PMID:25446075

  16. Digital safety I and C system in the Paks NPP (Hungary))

    SciTech Connect

    Eiler, J.

    2006-07-01

    The entire replacement of the original, Russian safety I and C system in the Paks NPP concluded successfully in 2003. The new, digital system was selected after a very thorough tendering process and installation was performed within the time-frame of normal refueling outages. The new system has shown very high reliability and flexibility in the past years. Several other nuclear power plants have initiated / completed the same replacement using the same type of equipment. This paper provides a summary on selected technical and organizational issues, as well as the main lessons learned in this very comprehensive and wide-scale project. (authors)

  17. MiR-145 regulates PAK4 via the MAPK pathway and exhibits an antitumor effect in human colon cells

    SciTech Connect

    Wang, Zhigang; Zhang, Xiaoping; Yang, Zhili; Du, Hangxiang; Wu, Zhenqian; Gong, Jianfeng; Yan, Jun; Zheng, Qi

    2012-10-26

    Highlights: Black-Right-Pointing-Pointer MiR-145 targets a putative binding site in the 3 Prime UTR of PAK4. Black-Right-Pointing-Pointer MiR-145 played an important role in inhibiting cell growth by directly targeting PAK4. Black-Right-Pointing-Pointer MiR-145 may function as tumor suppressors. -- Abstract: MicroRNAs (miRNAs) are regulators of numerous cellular events; accumulating evidence indicates that miRNAs play a key role in a wide range of biological functions, such as cellular proliferation, differentiation, and apoptosis in cancer. Down-regulated expression of miR-145 has been reported in colon cancer tissues and cell lines. The molecular mechanisms underlying miR-145 and the regulation of colon carcinogenesis remain unclear. In this study, we investigated the levels of miR-145 in human colon cancer cells using qRT-PCR and found markedly decreased levels compared to normal epithelial cells. We identified PAK4 as a novel target of miR-145 using informatics screening. Additionally, we demonstrated that miR-145 targets a putative binding site in the 3 Prime UTR of PAK4 and that its abundance is inversely associated with miR-145 expression in colon cancer cells; we confirmed this relationship using the luciferase reporter assay. Furthermore, restoration of miR-145 by mimics in SW620 cells significantly attenuated cell growth in vitro, in accordance with the inhibitory effects induced by siRNA mediated knockdown of PAK4. Taken together, these findings demonstrate that miR-145 downregulates P-ERK expression by targeting PAK4 and leads to inhibition of tumor growth.

  18. Crystal Structure of the SH3 Domain of beta PIX in Complex with a High Affinity Peptide from PAK2

    SciTech Connect

    Hoelz,A.; Janz, J.; Lawrie, S.; Corwin, B.; Lee, A.; Sakmar, T.

    2006-01-01

    The p21-activated kinases (PAKs) are important effector proteins of the small GTPases Cdc42 and Rac and control cytoskeletal rearrangements and cell proliferation. The direct interaction of PAKs with guanine nucleotide exchange factors from the PIX/Cool family, which is responsible for the localization of PAK kinases to focal complexes in the cell, is mediated by a 24-residue peptide segment in PAKs and an N-terminal src homology 3 (SH3) domain in PIX/Cool. The SH3-binding segment of PAK contains the atypical consensus-binding motif PxxxPR, which is required for unusually high affinity binding. In order to understand the structural basis for the high affinity and specificity of the PIX-PAK interaction, we solved crystal structures for the N-terminal SH3 domain of {beta}PIX and for the complex of the atypical binding segment of PAK2 with the N-terminal SH3 domain of {beta}PIX at 0.92 Angstroms and 1.3 Angstroms resolution, respectively. The asymmetric unit of the crystal contains two SH3 domains and two peptide ligands. The bound peptide adopts a conformation that allows for intimate contacts with three grooves on the surface of the SH3 domain that lie between the n-Src and RT-loops. Most notably, the arginine residue of the PxxxPR motif forms a salt-bridge and is tightly coordinated by a number of residues in the SH3 domain. This arginine-specific interaction appears to be the key determinant for the high affinity binding of PAK peptides. Furthermore, C-terminal residues of the peptide engage in additional interactions with the surface of the RT-loop, which significantly increases binding specificity. Compared to a recent NMR structure of a similar complex, our crystal structure reveals an alternate binding mode. Finally, we compare our crystal structure with the recently published {beta}PIX/Cbl-b complex structure, and suggest the existence of a molecular switch.

  19. The Serine-Threonine Protein Kinase PAK4 Is Dispensable in Zebrafish: Identification of a Morpholino-Generated Pseudophenotype

    PubMed Central

    Law, Sheran H. W.; Sargent, Thomas D.

    2014-01-01

    TALEN-based inactivation of the zebrafish pak4 gene resulted in embryos and adult fish that appear normal and fertile. This is in contrast to our previously published studies which were based on the use of antisense morpholino oligonucleotides (MOs). We have excluded potential explanations such as gene duplication, alternate splicing, cryptic initiation of translation, and translation-independent RNA function. Our conclusion is that pak4 is dispensable in zebrafish, and that even when corroborated by robust controls, such as RNA rescue, MOs may elicit misleading pseudophenotypes that do not correspond to results obtained by genetic mutations, and should thus be used with caution. PMID:24945275

  20. PAK1 regulates breast cancer cell invasion through secretion of matrix metalloproteinases in response to prolactin and three-dimensional collagen IV.

    PubMed

    Rider, Leah; Oladimeji, Peter; Diakonova, Maria

    2013-07-01

    p21-Activated serine-threonine kinase (PAK1) is implicated in breast cancer. We have shown previously that PAK1 is tyrosyl phosphorylated by prolactin (PRL)-activated Janus tyrosine kinase (JAK2). Although a role for both PRL and PAK1 in breast cancer is widely acknowledged, the mechanism remains poorly understood. In the present study, PRL-activated PAK1 stimulates the invasion of TMX2-28 human breast cancer cells through Matrigel. Three-dimensional (3D) collagen IV stimulates the secretion of the matrix proteases, metalloproteinase (MMP)-1 and -3 that is further enhanced by the PRL-dependent tyrosyl phosphorylation of PAK1. 3D collagen IV also stimulates the expression and secretion of MMP-2, but in contrast to MMP-1 and -3, PRL/PAK1 signaling down-regulates MMP-2 expression and secretion. In contrast, MMP-9 expression and secretion are stimulated by 3D collagen I, not collagen IV, and are not affected by PRL but are down-regulated by PAK1. MMP-1 and -3 are required and MMP-2 contributes to PRL-dependent invasion. ERK1/2 signaling appears to be required for the enhanced expression and secretion of MMP-1 and -3 and enhanced PRL-dependent invasion. p38 MAPK and c-Jun N-terminal kinase 1/2 pathways participate in production of MMP-1 and -3 as well as in PRL/PAK1-dependent cell invasion. Together, these data illustrate the complex interaction between the substratum and PRL/PAK1 signaling in human breast cancer cells and suggest a pivotal role for PRL-dependent PAK1 tyrosyl phosphorylation in MMP secretion. PMID:23744893

  1. PAK proteins and YAP-1 signalling downstream of integrin beta-1 in myofibroblasts promote liver fibrosis.

    PubMed

    Martin, Katherine; Pritchett, James; Llewellyn, Jessica; Mullan, Aoibheann F; Athwal, Varinder S; Dobie, Ross; Harvey, Emma; Zeef, Leo; Farrow, Stuart; Streuli, Charles; Henderson, Neil C; Friedman, Scott L; Hanley, Neil A; Piper Hanley, Karen

    2016-01-01

    Fibrosis due to extracellular matrix (ECM) secretion from myofibroblasts complicates many chronic liver diseases causing scarring and organ failure. Integrin-dependent interaction with scar ECM promotes pro-fibrotic features. However, the pathological intracellular mechanism in liver myofibroblasts is not completely understood, and further insight could enable therapeutic efforts to reverse fibrosis. Here, we show that integrin beta-1, capable of binding integrin alpha-11, regulates the pro-fibrotic phenotype of myofibroblasts. Integrin beta-1 expression is upregulated in pro-fibrotic myofibroblasts in vivo and is required in vitro for production of fibrotic ECM components, myofibroblast proliferation, migration and contraction. Serine/threonine-protein kinase proteins, also known as P21-activated kinase (PAK), and the mechanosensitive factor, Yes-associated protein 1 (YAP-1) are core mediators of pro-fibrotic integrin beta-1 signalling, with YAP-1 capable of perpetuating integrin beta-1 expression. Pharmacological inhibition of either pathway in vivo attenuates liver fibrosis. PAK protein inhibition, in particular, markedly inactivates the pro-fibrotic myofibroblast phenotype, limits scarring from different hepatic insults and represents a new tractable therapeutic target for treating liver fibrosis. PMID:27535340

  2. PAK proteins and YAP-1 signalling downstream of integrin beta-1 in myofibroblasts promote liver fibrosis

    PubMed Central

    Martin, Katherine; Pritchett, James; Llewellyn, Jessica; Mullan, Aoibheann F.; Athwal, Varinder S.; Dobie, Ross; Harvey, Emma; Zeef, Leo; Farrow, Stuart; Streuli, Charles; Henderson, Neil C.; Friedman, Scott L.; Hanley, Neil A.; Piper Hanley, Karen

    2016-01-01

    Fibrosis due to extracellular matrix (ECM) secretion from myofibroblasts complicates many chronic liver diseases causing scarring and organ failure. Integrin-dependent interaction with scar ECM promotes pro-fibrotic features. However, the pathological intracellular mechanism in liver myofibroblasts is not completely understood, and further insight could enable therapeutic efforts to reverse fibrosis. Here, we show that integrin beta-1, capable of binding integrin alpha-11, regulates the pro-fibrotic phenotype of myofibroblasts. Integrin beta-1 expression is upregulated in pro-fibrotic myofibroblasts in vivo and is required in vitro for production of fibrotic ECM components, myofibroblast proliferation, migration and contraction. Serine/threonine-protein kinase proteins, also known as P21-activated kinase (PAK), and the mechanosensitive factor, Yes-associated protein 1 (YAP-1) are core mediators of pro-fibrotic integrin beta-1 signalling, with YAP-1 capable of perpetuating integrin beta-1 expression. Pharmacological inhibition of either pathway in vivo attenuates liver fibrosis. PAK protein inhibition, in particular, markedly inactivates the pro-fibrotic myofibroblast phenotype, limits scarring from different hepatic insults and represents a new tractable therapeutic target for treating liver fibrosis. PMID:27535340

  3. Prenylated quinolinecarboxylic acid derivative suppresses immune response through inhibition of PAK2.

    PubMed

    Ogura, Masato; Kikuchi, Haruhisa; Suzuki, Toshiyuki; Yamaki, Junko; Homma, Miwako K; Oshima, Yoshiteru; Homma, Yoshimi

    2016-04-01

    Development of new immunosuppressing agents is necessary in organ transplantation or immune diseases. Because Ppc-1 exhibits a suppressing effect on interleukin-2 (IL2) production in Jurkat cells, we synthesized and screened Ppc-1 derivatives that preserve prenylated quinolinecarboxylic acid (PQA) structure, and identified compound 18 (PQA-18) as a novel molecule with immunosuppressing effect. PQA-18 suppressed not only IL2 but also IL4, IL6, and tumor necrosis factor-α production in human peripheral lymphocytes without affecting cell viability. Two-dimensional gel electrophoresis analysis and in vitro kinase assay revealed that PQA-18 inhibits kinase activity of p21-activated kinase 2 (PAK2). Administration of PQA-18 by intraperitoneal injection suppressed the population of a subset of regulatory T cells and the immunoglobulin (Ig) production against T cell-dependent antigens in mice. Treatment with the PQA-18 ointment on Nc/Nga mice, a model of human atopic dermatitis, improved skin lesions and serum IgE levels. These results suggest that PQA-18 is a unique PAK2 inhibitor with potent immunosuppressing effects in vitro and in vivo. PQA-18 may be a valuable lead for the development of novel immunosuppressants. PMID:26827943

  4. Comprehensive Community-Based Services for Offenders Information Pak. Part 3: A System for Delivering Comprehensive Services to Offenders.

    ERIC Educational Resources Information Center

    Schroeder, Paul E.

    This paper describing a system for delivering comprehensive services to offenders is the third of the five-part Comprehensive Community-Based Services for Offenders Information PAK that provides guidelines for developing a system to improve exoffender service delivery. (Parts 1 and 2, which also contain printed information, are available…

  5. Group I PAK inhibitor IPA-3 induces cell death and affects cell adhesivity to fibronectin in human hematopoietic cells.

    PubMed

    Kuželová, Kateřina; Grebeňová, Dana; Holoubek, Aleš; Röselová, Pavla; Obr, Adam

    2014-01-01

    P21-activated kinases (PAKs) are involved in the regulation of multiple processes including cell proliferation, adhesion and migration. However, the current knowledge about their function is mainly based on results obtained in adherent cell types. We investigated the effect of group I PAK inhibition using the compound IPA-3 in a variety of human leukemic cell lines (JURL-MK1, MOLM-7, K562, CML-T1, HL-60, Karpas-299, Jurkat, HEL) as well as in primary blood cells. IPA-3 induced cell death with EC50 ranging from 5 to more than 20 μM. Similar range was found for IPA-3-mediated dephosphorylation of a known PAK downstream effector, cofilin. The cell death was associated with caspase-3 activation, PARP cleavage and apoptotic DNA fragmentation. In parallel, 20 μM IPA-3 treatment induced rapid and marked decrease of the cell adhesivity to fibronectin. Per contra, partial reduction of PAK activity using lower dose IPA-3 or siRNA resulted in a slight increase in the cell adhesivity. The changes in the cell adhesivity were also studied using real-time microimpedance measurement and by interference reflection microscopy. Significant differences in the intracellular IPA-3 level among various cell lines were observed indicating that an active mechanism is involved in IPA-3 transport. PMID:24664099

  6. p-21 activated kinase 4 (PAK4) maintains stem cell-like phenotypes in pancreatic cancer cells through activation of STAT3 signaling.

    PubMed

    Tyagi, Nikhil; Marimuthu, Saravanakumar; Bhardwaj, Arun; Deshmukh, Sachin K; Srivastava, Sanjeev K; Singh, Ajay P; McClellan, Steven; Carter, James E; Singh, Seema

    2016-01-28

    Pancreatic cancer (PC) remains a highly lethal malignancy due to its unusual chemoresistance and high aggressiveness. A subpopulation of pancreatic tumor cells, known as cancer stem cells (CSCs), is considered responsible not only for tumor-maintenance, but also for its widespread metastasis and therapeutic failure. Here we investigated the role of p-21 activated kinase 4 (PAK4) in driving PC stemness properties. Our data demonstrate that triple-positive (CD24(+)/CD44(+)/EpCAM(+)) subpopulation of pancreatic CSCs exhibits greater level of PAK4 as compared to triple-negative (CD24(-)/CD44(-)/EpCAM(-)) cells. Moreover, PAK4 silencing in PC cells leads to diminished fraction of CD24, CD44, and EpCAM positive cells. Furthermore, we show that PAK4-silenced PC cells exhibit decreased sphere-forming ability and increased chemosensitivity to gemcitabine toxicity. PAK4 expression is also associated with enhanced levels of stemness-associated transcription factors (Oct4/Nanog/Sox2 and KLF4). Furthermore, our data show decreased nuclear accumulation and transcriptional activity of STAT3 in PAK4-silenced PC cells and restitution of its activity leads to restoration of stem cell phenotypes. Together, our findings deliver first experimental evidence for the involvement of PAK4 in PC stemness and support its clinical utility as a novel therapeutic target in PC. PMID:26546043

  7. microRNA-7 regulates cell growth, migration and invasion via direct targeting of PAK1 in thyroid cancer.

    PubMed

    Yue, Kai; Wang, Xudong; Wu, Yansheng; Zhou, Xuan; He, Qinghua; Duan, Yuansheng

    2016-09-01

    The expression and function of microRNA-7 (miR-7) has been studied in a variety of different cancer types. However, to date, no studies have investigated the expression of miR‑7 in human thyroid cancer. In the present study, the expression levels and biological function of miR‑7 were investigated in human thyroid cancer, with the aim of evaluating whether it may serve as a therapeutic biomarker. The expression levels of miR‑7 in human thyroid cancer tissues, matched, adjacent normal tissues, normal thyroid tissues and human thyroid cancer cell lines were determined using RT‑qPCR and western blot analysis. To explore the functional role of miR‑7 in human thyroid cancer cell lines, MTT assays, cell migration and invasion assays were employed. TargetScan software identified p21 activated kinase‑1 (PAK1) as a putative interacting partner of miR‑7. Therefore, functional assays were performed to explore the effects of endogenous PAK1 in thyroid cancer. In the present study, miR‑7 was significantly downregulated in thyroid cancer tissues and cells compared with normal thyroid tissue samples. A correlation between miR‑7 expression and thyroid tumor stage was also observed. Ectopic expression of miR‑7 was found to suppress the proliferation, migra-tion and invasion of thyroid cancer cells in vitro. Dual-luciferase reporter assays demonstrated that PAK1 was a direct target of miR-7 in vitro. RT-qPCR and western blot analysis demonstrated that miR‑7 negatively regulates PAK1 protein expression but has no effect on PAK1 mRNA expression. Knockdown of PAK1 expression markedly suppressed thyroid cancer cell proliferation, migration and invasion. These results suggest that miR‑7 functions as a tumor suppressor by targeting PAK1 directly and may therefore present a novel therapeutic target for the treatment of thyroid cancer. PMID:27430434

  8. A Rac-Pak signaling pathway is essential for ErbB2-mediated transformation of human breast epithelial cancer cells

    PubMed Central

    Arias-Romero, Luis E.; Villamar-Cruz, Olga; Pacheco, Almudena; Kosoff, Rachelle; Huang, Min; Muthuswamy, Senthil K.; Chernoff, Jonathan

    2010-01-01

    The activation of receptor tyrosine kinases, particularly ErbB2, plays an important role in the genesis of breast cancer. ErbB2 kinase activity promotes Ras-mediated stimulation of downstream protein kinase cascades, including the Ras/Raf-1/Mek/extracellular-signal regulated kinase (Erk) pathway, leading to tumor cell growth and migration. Signaling through the Ras-Erk pathway can be influenced by p21-activated kinase-1 (Pak1), an effector of the Rho family GTPases Rac and Cdc42. In this study, we asked if ErbB2 expression correlates with Pak1 and Erk activity in human breast cancer specimens, and if Pak1 signaling is required for ErbB2 transformation in a 3D in vitro setting and in xenografts. We found a correlation between ErbB2 expression and activation of Pak in estrogen-receptor positive human breast tumor samples and observed that in 3D cultures, activation of Rac-Pak1 pathway by ErbB2 homodimers induced growth factor independent proliferation and promoted disruption of three-dimensional mammary acinar-like structures through activation of the Erk and Akt pathways. Further, we found that inhibition of Pak1 by small molecules compromised activation of Erk and Akt, resulting in reversion of the malignant phenotype and restoration of normal acinar architecture. Finally, ErbB2-amplified breast cancer cells expressing a specific Pak inhibitor showed delayed tumor formation and down-regulation of Erk and Akt signaling in vivo. These data imply that the Rac-Pak pathway is vital to ErbB2-mediated transformation and that Pak inhibitors represent plausible drug targets in breast cancers in which ErbB2 signaling is activated. PMID:20711231

  9. High throughput screening of CO2-tolerating microalgae using GasPak bags

    PubMed Central

    2013-01-01

    Background Microalgae are diverse in terms of their speciation and function. More than 35,000 algal strains have been described, and thousands of algal cultures are maintained in different culture collection centers. The ability of CO2 uptake by microalgae varies dramatically among algal species. It becomes challenging to select suitable algal candidates that can proliferate under high CO2 concentration from a large collection of algal cultures. Results Here, we described a high throughput screening method to rapidly identify high CO2 affinity microalgae. The system integrates a CO2 mixer, GasPak bags and microplates. Microalgae on the microplates will be cultivated in GasPak bags charged with different CO2 concentrations. Using this method, we identified 17 algal strains whose growth rates were not influenced when the concentration of CO2 was increased from 2 to 20% (v/v). Most CO2 tolerant strains identified in this study were closely related to the species Scenedesmus and Chlorococcum. One of Scenedesmus strains (E7A) has been successfully tested in in the scale up photo bioreactors (500 L) bubbled with flue gas which contains 10-12% CO2. Conclusion Our high throughput CO2 testing system provides a rapid and reliable way for identifying microalgal candidate strains that can grow under high CO2 condition from a large pool of culture collection species. This high throughput system can also be modified for selecting algal strains that can tolerate other gases, such as NOx, SOx, or flue gas. PMID:24341988

  10. The Pakistan National Emergency Department Surveillance Study (Pak-NEDS): Introducing a pilot surveillance

    PubMed Central

    2015-01-01

    Background Evidence-based decision making is essential for appropriate prioritization and service provision by healthcare systems. Despite higher demands, data needs for this practice are not met in many cases in low- and middle-income countries because of underdeveloped sources, among other reasons. Emergency departments (EDs) provide an important channel for such information because of their strategic position within healthcare systems. This paper describes the design and pilot test of a national ED based surveillance system suitable for the Pakistani context. Methods The Pakistan National Emergency Department Surveillance Study (Pak-NEDS) was pilot tested in the emergency departments of seven major tertiary healthcare centres across the country. The Aga Khan University, Karachi, served as the coordinating centre. Key stakeholders and experts from all study institutes were involved in outlining data needs, development of the study questionnaire, and identification of appropriate surveillance mechanisms such as methods for data collection, monitoring, and quality assurance procedures. The surveillance system was operational between November 2010 and March 2011. Active surveillance was done 24 hours a day by data collectors hired and trained specifically for the study. All patients presenting to the study EDs were eligible participants. Over 270,000 cases were registered in the surveillance system over a period of four months. Coverage levels in the final month ranged from 91-100% and were highest in centres with the least volume of patients. Overall the coverage for the four months was 79% and crude operational costs were less than $0.20 per patient. Conclusions Pak-NEDS is the first multi-centre ED based surveillance system successfully piloted in a sample of major EDs having some of the highest patient volumes in Pakistan. Despite the challenges identified, our pilot shows that the system is flexible and scalable, and could potentially be adapted for many other

  11. Validation of the BrockTB Stat-Pak Assay for Detection of Tuberculosis in Eurasian Badgers (Meles meles) and Influence of Disease Severity on Diagnostic Accuracy▿

    PubMed Central

    Chambers, Mark A.; Crawshaw, Tim; Waterhouse, Sue; Delahay, Richard; Hewinson, R. Glyn; Lyashchenko, Konstantin P.

    2008-01-01

    A lateral-flow immunoassay (BrockTB Stat-Pak) for detecting tuberculosis in Eurasian badgers was 49% sensitive and 93% specific against culture for M. bovis (n = 1,464) at necropsy. However, the sensitivity was significantly higher (66 to 78%) in animals with more severe tuberculosis, indicating that the BrockTB Stat-Pak may be useful for the detection of badgers with the greatest risk of transmitting disease. PMID:18272706

  12. PAK1-deficiency/down-regulation reduces brood size, activates HSP16.2 gene and extends lifespan in Caenorhabditis elegans.

    PubMed

    Yanase, S; Luo, Y; Maruta, H

    2013-02-01

    There is an increasing evidence that the oncogenic kinase PAK1 is responsible not only for malignant transformation, but also for several other diseases such as inflammatory diseases (asthma and arthritis), infectious diseases including malaria, AIDS, and flu, as well as a series of neuronal diseases/disorders (neurofibromatosis, tuberous sclerosis, Alzheimer's diseases, Huntington's disease, epilepsy, depression, learning deficit, etc.) which often cause premature death. Interestingly, a few natural PAK1-blockers such as curcumin, caffeic acid (CA) and rosmarinic acid (RA) extend the lifespan of the nematode Caenorhabditis elegans or fruit flies. Here, to explore the possibility that C. elegans could provide us with a quick and inexpensive in vivo screening system for a series of more potent but safe (non-toxic) PAK1-blocking therapeutics, we examined the effects of PAK1-deficiency or down-regulation on a few selected functions of this worm, including reproduction, expression of HSP16.2 gene, and lifespan. In short, we found that PAK1 promotes reproduction, whereas it inactivates HSP16.2 gene and shortens lifespan, as do PI-3 kinase (AGE-1), TOR, and insulin-like signalling /ILS (Daf-2) in this worm. These findings not only support the "trade-off" theory on reproduction versus lifespan, but also suggest the possibility that the reduced reproduction (or HSP16.2 gene activation) of this worm could be used as the first indicator of extended lifespan for a quick in vivo screening for PAK1-blockers. PMID:23524941

  13. Pak4 Is Required during Epithelial Polarity Remodeling through Regulating AJ Stability and Bazooka Retention at the ZA

    PubMed Central

    Walther, Rhian F.; Nunes de Almeida, Francisca; Vlassaks, Evi; Burden, Jemima J.; Pichaud, Franck

    2016-01-01

    Summary The ability of epithelial cells to assemble into sheets relies on their zonula adherens (ZA), a circumferential belt of adherens junction (AJ) material, which can be remodeled during development to shape organs. Here, we show that during ZA remodeling in a model neuroepithelial cell, the Cdc42 effector P21-activated kinase 4 (Pak4/Mbt) regulates AJ morphogenesis and stability through β-catenin (β-cat/Arm) phosphorylation. We find that β-catenin phosphorylation by Mbt, and associated AJ morphogenesis, is needed for the retention of the apical determinant Par3/Bazooka at the remodeling ZA. Importantly, this retention mechanism functions together with Par1-dependent lateral exclusion of Par3/Bazooka to regulate apical membrane differentiation. Our results reveal an important functional link between Pak4, AJ material morphogenesis, and polarity remodeling during organogenesis downstream of Par3. PMID:27052178

  14. Oncogenic epithelial cell-derived exosomes containing Rac1 and PAK2 induce angiogenesis in recipient endothelial cells

    PubMed Central

    Gopal, Shashi K.; Greening, David W.; Hanssen, Eric G.; Zhu, Hong-Jian; Simpson, Richard J.; Mathias, Rommel A.

    2016-01-01

    The metastatic cascade describes the escape of primary tumour cells to distant secondary sites. Cells at the leading tumour edge are thought to undergo epithelial-mesenchymal transition (EMT), to enhance their motility and invasion for spreading. Whether EMT cells directly promote tumour angiogenesis, and the role of exosomes (30-150 nm extracellular vesicles) remains largely unknown. We examined the functional effects of exosomes from MDCK cells, MDCK cells stably expressing YBX1 (MDCKYBX1, intermediate EMT), and Ras-transformed MDCK cells (21D1 cells, complete EMT). 2F-2B cell motility and tube formation (length and branching) was significantly increased following supplementation with MDCKYBX1 or 21D1 exosomes, but not MDCK exosomes. Next, Matrigel™ plugs containing exosome-supplemented 2F-2B cells were subcutaneously injected into mice. Systemic perfusion was only observed for plugs supplemented with MDCKYBX1 or 21D1 exosomes. Comparative proteomics revealed that 21D1 exosomes contained VEGF-associated proteins, while MDCKYBX1 exosomes were enriched with activated Rac1 and PAK2. To validate, 2F-2B cells and HUVECs were pre-treated with PAK inhibitors prior to exosome supplementation. PAK inhibition nullified the effects of MDCKYBX1 exosomes by reducing the tube length and branching to baseline levels. By contrast, the effects of 21D1 exosomes were not significantly decreased. Our results demonstrate for the first time that oncogenic cells undergoing EMT can communicate with endothelial cells via exosomes, and establish exosomal Rac1/PAK2 as angiogenic promoters that may function from early stages of the metastatic cascade. PMID:26919098

  15. Towards the Seismic Hazard Reassessment of Paks NPP (Hungary) Site: Seismicity and Sensitivity Studies

    NASA Astrophysics Data System (ADS)

    Toth, Laszlo; Monus, Peter; Gyori, Erzsebet; Grenerczy, Gyula; Janos Katona, Tamas; Kiszely, Marta

    2015-04-01

    In context of extension of Paks Nuclear Power Plant by new units, a comprehensive site seismic hazard evaluation program has been developed that is already approved by the Hungarian Authorities. This includes a 3D seismic survey, drilling of several deep boreholes, extensive geological mapping, and geophysical investigations at the site and its vicinity, as well as on near regional, and regional scale. Furthermore, all relevant techniques of modern space geodesy (GPS, PSInSAR) will be also utilized to construct a new seismotectonic model. The implementation of the project is still in progress. In the presentation, some important elements of the new seismic hazard assessment are highlighted, and some results obtained in the preliminary phase of the program are presented and discussed. The first and most important component of the program is the compilation of the seismological database that is developed on different time scale zooming on different event recurrence rates such as paleo-earthquakes (10-1/a). In 1995, Paks NPP installed and started to operate a sensitive microseismic monitoring network capable for locating earthquakes as small as magnitude 2.0 within about 100 km of the NPP site. During the two decades of operation, the microseismic monitoring network located some 2,000 earthquakes within the region of latitude 45.5 - 49 N and longitude 16 - 23 E. Out of the total number of events, 130 earthquakes were reported as 'felt events'. The largest earthquake was an event of ML 4.8, causing significant damage in the epicenter area. The results of microseismic monitoring provide valuable data for seismotectonic modelling and results in more accurate earthquake recurrence equations. The first modern PSHA of Paks NPP site was carried out in 1995. Complex site characterization project was implemented and hazard curves had been evaluated for 10-3 - 10-5 annual frequency. As a follow-up, PSHA results have been reviewed and updated in the frame of periodic safety

  16. PAK1 and CtBP1 Regulate the Coupling of Neuronal Activity to Muscle Chromatin and Gene Expression

    PubMed Central

    Thomas, Jean-Luc; Ravel-Chapuis, Aymeric; Valente, Carmen; Corda, Daniela; Méjat, Alexandre

    2015-01-01

    Acetylcholine receptor (AChR) expression in innervated muscle is limited to the synaptic region. Neuron-induced electrical activity participates in this compartmentalization by promoting the repression of AChR expression in the extrasynaptic regions. Here, we show that the corepressor CtBP1 (C-terminal binding protein 1) is present on the myogenin promoter together with repressive histone marks. shRNA-mediated downregulation of CtBP1 expression is sufficient to derepress myogenin and AChR expression in innervated muscle. Upon denervation, CtBP1 is displaced from the myogenin promoter and relocates to the cytoplasm, while repressive histone marks are replaced by activating ones concomitantly to the activation of myogenin expression. We also observed that upon denervation the p21-activated kinase 1 (PAK1) expression is upregulated, suggesting that phosphorylation by PAK1 may be involved in the relocation of CtBP1. Indeed, preventing CtBP1 Ser158 phosphorylation induces CtBP1 accumulation in the nuclei and abrogates the activation of myogenin and AChR expression. Altogether, these findings reveal a molecular mechanism to account for the coordinated control of chromatin modifications and muscle gene expression by presynaptic neurons via a PAK1/CtBP1 pathway. PMID:26416879

  17. PAK1 and CtBP1 Regulate the Coupling of Neuronal Activity to Muscle Chromatin and Gene Expression.

    PubMed

    Thomas, Jean-Luc; Moncollin, Vincent; Ravel-Chapuis, Aymeric; Valente, Carmen; Corda, Daniela; Méjat, Alexandre; Schaeffer, Laurent

    2015-12-01

    Acetylcholine receptor (AChR) expression in innervated muscle is limited to the synaptic region. Neuron-induced electrical activity participates in this compartmentalization by promoting the repression of AChR expression in the extrasynaptic regions. Here, we show that the corepressor CtBP1 (C-terminal binding protein 1) is present on the myogenin promoter together with repressive histone marks. shRNA-mediated downregulation of CtBP1 expression is sufficient to derepress myogenin and AChR expression in innervated muscle. Upon denervation, CtBP1 is displaced from the myogenin promoter and relocates to the cytoplasm, while repressive histone marks are replaced by activating ones concomitantly to the activation of myogenin expression. We also observed that upon denervation the p21-activated kinase 1 (PAK1) expression is upregulated, suggesting that phosphorylation by PAK1 may be involved in the relocation of CtBP1. Indeed, preventing CtBP1 Ser158 phosphorylation induces CtBP1 accumulation in the nuclei and abrogates the activation of myogenin and AChR expression. Altogether, these findings reveal a molecular mechanism to account for the coordinated control of chromatin modifications and muscle gene expression by presynaptic neurons via a PAK1/CtBP1 pathway. PMID:26416879

  18. A p21-activated kinase (PAK1) signaling cascade coordinately regulates F-actin remodeling and insulin granule exocytosis in pancreatic β cells

    PubMed Central

    Kalwat, Michael A.; Yoder, Stephanie M.; Wang, Zhanxiang; Thurmond, Debbie C.

    2012-01-01

    Human islet studies implicate an important signaling role for the Cdc42 effector protein p21-activated kinase (PAK1) in the sustained/second-phase of insulin secretion. Because human islets from type 2 diabetic donors lack ~80% of normal PAK1 protein levels, the mechanistic requirement for PAK1 signaling in islet function was interrogated. Similar to MIN6 β cells, human islets elicited glucose-stimulated PAK1 activation that was sensitive to the PAK1 inhibitor, IPA3. Given that sustained insulin secretion has been correlated with glucose-induced filamentous actin (F-actin) remodeling, we tested the hypothesis that a Cdc42-activated PAK1 signaling cascade is required to elicit F-actin remodeling to mobilize granules to the cell surface. Live-cell imaging captured the glucose-induced cortical F-actin remodeling in MIN6 β cells; IPA3-mediated inhibition of PAK1 abolished this remodeling. IPA3 also ablated glucose-stimulated insulin granule accumulation at the plasma membrane, consistent with its role in sustained/second-phase insulin release. Both IPA3 and a selective inhibitor of the Cdc42 GTPase, ML-141, blunted the glucose-stimulated activation of Raf-1, suggesting Raf-1 to be downstream of Cdc42→PAK1. IPA3 also inhibited MEK1/2 activation, implicating the MEK1/2→ERK1/2 cascade to occur downstream of PAK1. Importantly, PD0325901, a new selective inhibitor of MEK1/2→ERK1/2 activation, impaired F-actin remodeling and the sustained/amplification pathway of insulin release. Taken together, these data suggest that glucose-mediated activation of Cdc42 leads to activation of PAK1 and prompts activation of its downstream targets Raf-1, MEK1/2 and ERK1/2 to elicit F-actin remodeling and recruitment of insulin granules to the plasma membrane to support the sustained phase of insulin release. PMID:23246867

  19. Mangrove Colonization: Mangrove Progression Over the Growing Pak Phanang (SE Thailand) Mud Flat

    NASA Astrophysics Data System (ADS)

    Panapitukkul, N.; Duarte, C. M.; Thampanya, U.; Kheowvongsri, P.; Srichai, N.; Geertz-Hansen, O.; Terrados, J.; Boromthanarath, S.

    1998-07-01

    A combination of remote sensing techniques and in situmeasurements along a chronosequence was used to elucidate the rate of progression of the mangrove forest in the Pak Phanang Bay (SE Thailand), a large bay with an extended and rapidly accreting mud flat. The examination of black and white aerial photographs of the forest in 1966, 1974, 1989 and 1995, and satellite images in 1985, 1990 and 1994 revealed that the mangrove forest located in the eastern bank of the bay was progressing over the mud flat. The rate of progression was estimated, from examination of changes in the position of the forest edge with time in the series of images, to average 38·6 m year -1over the 28-year interval encompassed by the images. Mangrove progression rates were fastest between 1966 and 1974 and slowest between 1974 and 1985, remaining uniform at about 30 m year -1thereafter. The in situexamination of vegetation along transects in the area of fastest mangrove progression showed an average progression rate of 53·12±5·86 m year -1, quite similar to the estimate (48·4 m year -1) derived from remote sensing techniques for the area where the transects were surveyed. Avicennia albawas found to dominate the vegetation at the progressing edge of the mangrove, followed by Sonneratia caseolaris, with Rhizophora apiculatabeing present only occasionally. The fast colonization of A. albaover the mud flat was supported by a large export flux of mangrove propagules from the channels draining the mangrove forest, which averaged 3715±920 and 1900±808 fruits day -1in each of the channels examined. Extrapolation of the long-term mean mangrove progression rate observed along the eastern bank of the Pak Phanang Bay suggested that this mangrove forest will increase by 33 ha year -1. These results provide evidence that natural mangrove colonization can be a rapid process if sufficient propagules of the pioneer species ( A. albaand S. caseolaris) are available, and point, therefore, to alternative

  20. Rac1/Pak1/p38/MMP-2 axis regulates angiogenesis in ovarian cancer

    PubMed Central

    Gonzalez-Villasana, Vianey; Fuentes-Mattei, Enrique; Ivan, Cristina; Dalton, Heather J.; Rodriguez-Aguayo, Cristian; Fernandez-de Thomas, Ricardo J.; Aslan, Burcu; Monroig, Paloma del C.; Velazquez-Torres, Guermarie; Previs, Rebecca A.; Pradeep, Sunila; Kahraman, Nermin; Wang, Huamin; Kanlikilicer, Pinar; Ozpolat, Bulent; Calin, George; Sood, Anil K.; Lopez-Berestein, Gabriel

    2015-01-01

    Purpose Zoledronic acid (ZA) is being increasingly recognized for its anti-tumor properties, but the underlying functions are not well understood. In this study, we hypothesized that ZA inhibits ovarian cancer (OC) angiogenesis preventing Rac1 activation. Experimental Design The biological effects of ZA were examined using a series of in vitro (cell invasion, cytokine production, Rac1 activation, reverse-phase protein array and in vivo (orthotopic mouse models) experiments. Results There was significant inhibition of OC (HeyA8-MDR and OVCAR-5) cell invasion as well as reduced production of pro-angiogenic cytokines in response to ZA treatment. Furthermore, ZA inactivated Rac1 and decreased the levels of Pak1/p-38/matrix metalloproteinase-2 in OC cells. In vivo, ZA reduced tumor growth, angiogenesis and cell proliferation and inactivated Rac1 in both HeyA8-MDR and OVCAR-5 models. These in vivo antitumor effects were enhanced in both models when ZA was combined with nab-paclitaxel. Conclusion ZA has robust anti-tumor and anti-angiogenic activity and merits further clinical development as OC treatment. PMID:25595279

  1. Industrial-hygiene walk-through survey report of Tetra Pak, Inc. , Denton, Texas

    SciTech Connect

    McCammon, C.S.; Krishnan, E.R.; Goodman, R.J.

    1987-06-05

    A walk-through industrial-hygiene survey was conducted at the Tetra Pak Denton facility in Denton, Texas to determine possible employee exposure to acrylates or methacrylates. Acrylated inks and coatings have been used at this facility since 1984 to produce aseptic flexible packaging material for the food industry. There were three offset printing press lines used at the company, each with five offset presses to apply different colored inks. As many as five separate wet-on-wet applications of acrylated ink formulations sometimes preceded the coating application. After the inks were applied they were passed through an offset blanket coater. Following this step an electron-beam-curing unit radiated the inks and coating. Environmental enclosures surrounded the offset-printing presses in order to cut down on noise and mist. Of the 176 employees at this company, 37 had potential contact with acrylates. No air monitoring has been conducted at this facility for acrylates. One case of dermatitis arose at the company since 1984 and possibly was related directly to skin contact with acrylates. There was a safety program in place at the company and personnel records were maintained for each employee.

  2. Tip Gap Flow Control of A Pak-B Turbine Blade

    NASA Astrophysics Data System (ADS)

    Stephens, Julia

    2005-11-01

    A high-speed linear cascade is used to investigate passive and active approaches for controlling the over-tip leakage flow associated with the turbine blades in the low-pressure stage of a gas turbine engine. The cascade consists of Pratt & Whitney ``PakB'' blades with varying gap sizes ranging from 0.5 to 5.0 percent of the blade axial chord. Reynolds numbers between 100K and 500K that correspond to tip relative Mach numbers of 0.04 to 0.21 were investigated. Pressure ports on the endwall as well as at the midspan and tip of the blade are used to evaluate the flow. Additionally, a five-hole probe that was traversed in the blade wakes was used to determine total pressure loss coefficients and local velocity vectors. Two types of flow control devices were investigated. One consisted of a passive partial ``squeeler'' tip that locally reduced the gap size. The other consisted of a plasma actuator located on the blade tip was designed to produce unsteady disturbances which were receptive to the over-tip flow jet and shear layers. The effects of both these approaches are contrasted.

  3. Reactor Dosimetry Aspects of the Service Life Extension of the Hungarian Paks NPP

    NASA Astrophysics Data System (ADS)

    Zsolnay, Eva M.; Czifrus, Szabolcs; Fehér, Sándor; Hordósy, Gábor; Keresztúri, András; Kresz, Norbert; Oszvald, Ferenc

    2016-02-01

    The service life of the Hungarian Paks Nuclear Power Plant (NPP) will be extended from the originally planned 30 years to 50 years. To improve the reliability of the results obtained in frame of the old reactor pressure vessel (RPV) surveillance programme, new methods have been developed, and based on them, the old exposition data have been re-evaluated for all the four reactor units. At the same time, a new RPV surveillance programme has been developed and introduced, and long term irradiations have been performed to determine the radiation damage of the surveillance specimens due to the high fast neutron exposition. Neutron transport calculations have been performed with a validated neutron transport code system to determine the fast neutron exposition of the RPVs during the extended service life. The cavity dosimetry is in the introductory phase. This paper presents the new developments in the field of the RPV surveillance dosimetry and summarises the results obtained. According to the results the service life of the NPP can safely be extended for the planned 50 years.

  4. Increased expression of microRNA-221 inhibits PAK1 in endothelial progenitor cells and impairs its function via c-Raf/MEK/ERK pathway

    SciTech Connect

    Zhang, Xiaoping; Mao, Haian; Chen, Jin-yuan; Wen, Shengjun; Li, Dan; Ye, Meng; Lv, Zhongwei

    2013-02-15

    Highlights: ► MicroRNA-221 is upregulated in the endothelial progenitor cells of atherosclerosis patients. ► PAK1 is a direct target of microRNA-221. ► MicroRNA-221 inhibits EPCs proliferation through c-Raf/MEK/ERK pathway. -- Abstract: Coronary artery disease (CAD) is associated with high mortality and occurs via endothelial injury. Endothelial progenitor cells (EPCs) restore the integrity of the endothelium and protect it from atherosclerosis. In this study, we compared the expression of microRNAs (miRNAs) in EPCs in atherosclerosis patients and normal controls. We found that miR-221 expression was significantly up-regulated in patients compared with controls. We predicted and identified p21/Cdc42/Rac1-activated kinase 1 (PAK1) as a novel target of miR-221 in EPCs. We also demonstrated that miR-221 targeted a putative binding site in the 3′UTR of PAK1, and absence of this site was inversely associated with miR-221 expression in EPCs. We confirmed this relationship using a luciferase reporter assay. Furthermore, overexpression of miR-221 in EPCs significantly decreased EPC proliferation, in accordance with the inhibitory effects induced by decreased PAK1. Overall, these findings demonstrate that miR-221 affects the MEK/ERK pathway by targeting PAK1 to inhibit the proliferation of EPCs.

  5. PAK2 is an effector of TSC1/2 signaling independent of mTOR and a potential therapeutic target for Tuberous Sclerosis Complex

    PubMed Central

    Alves, Maria M.; Fuhler, Gwenny M.; Queiroz, Karla C.S.; Scholma, Jetse; Goorden, Susan; Anink, Jasper; Arnold Spek, C.; Hoogeveen-Westerveld, Marianne; Bruno, Marco J.; Nellist, Mark; Elgersma, Ype; Aronica, Eleonora; Peppelenbosch, Maikel P.

    2015-01-01

    Tuberous sclerosis complex (TSC) is caused by inactivating mutations in either TSC1 or TSC2 and is characterized by uncontrolled mTORC1 activation. Drugs that reduce mTOR activity are only partially successful in the treatment of TSC, suggesting that mTOR-independent pathways play a role in disease development. Here, kinome profiles of wild-type and Tsc2−/− mouse embryonic fibroblasts (MEFs) were generated, revealing a prominent role for PAK2 in signal transduction downstream of TSC1/2. Further investigation showed that the effect of the TSC1/2 complex on PAK2 is mediated through RHEB, but is independent of mTOR and p21RAC. We also demonstrated that PAK2 over-activation is likely responsible for the migratory and cell cycle abnormalities observed in Tsc2−/− MEFs. Finally, we detected high levels of PAK2 activation in giant cells in the brains of TSC patients. These results show that PAK2 is a direct effector of TSC1-TSC2-RHEB signaling and a new target for rational drug therapy in TSC. PMID:26412398

  6. Rainfall Trends over the Indo-Pak Summer Monsoon and Related Large-Scale Dynamics

    NASA Astrophysics Data System (ADS)

    Latif, Muhammad; Syed, Faisal; Hannachi, Abdel

    2016-04-01

    The study of regional rainfall trends over South Asia is critically important for food security and infrastructure. This study investigates the presence of trends in seasonal and sub-seasonal (June through September-JJAS) rainfall obtained from multiple observed datasets. The obtained results identified a dipole-type structure in rainfall trends over the region north of the Indo-Pak subcontinent, where significant increasing trends are seen over the core monsoon region of Pakistan and significant decreasing trends are observed over the central-north India and adjacent areas. The study strongly suggests that strengthening of Vertically Integrated Meridional Moisture Transport (VIMMT) over the Arabian Sea is likely reason for the trend of rainfall in the core monsoon region of Pakistan. In contrast, over the central-north India region, the rainfall trends are significantly decreasing due to the weakening of IMT over the Bay of Bengal. The leading EOF clearly shows the strengthening (weakening) patterns of VIMMT over the Arabian Sea (Bay of Bengal) in seasonal and sub-seasonal interannual time-scales. The regression analysis between the principal components and rainfall confirms the dipole pattern over the region. Our results also suggest that the Circumglobal Teleconnection in upper troposphere influence in maintaining the mean rainfall over Pakistan via cross-equatorial flow of moisture into the Arabian Sea. We also investigate seasonal JJAS rainfall trends using historical and climate change (RCP4.5 and RCP8.5) simulations from a set of regional climate models from Coupled Model Intercomparison Project (CMIP5). Trends and asymmetry of seasonal rainfall show great variability across models. Meridional moisture transport and associated large-scale dynamics will also be discussed.

  7. Phosphorylation of Threonine 794 on Tie1 by Rac1/PAK1 Reveals a Novel Angiogenesis Regulatory Pathway

    PubMed Central

    Reinardy, Jessica L.; Corey, Daniel M.; Golzio, Christelle; Mueller, Sarah B.; Katsanis, Nicholas; Kontos, Christopher D.

    2015-01-01

    The endothelial receptor tyrosine kinase (RTK) Tie1 was discovered over 20 years ago, yet its precise function and mode of action remain enigmatic. To shed light on Tie1’s role in endothelial cell biology, we investigated a potential threonine phosphorylation site within the juxtamembrane domain of Tie1. Expression of a non-phosphorylatable mutant of this site (T794A) in zebrafish (Danio rerio) significantly disrupted vascular development, resulting in fish with stunted and poorly branched intersomitic vessels. Similarly, T794A-expressing human umbilical vein endothelial cells formed significantly shorter tubes with fewer branches in three-dimensional Matrigel cultures. However, mutation of T794 did not alter Tie1 or Tie2 tyrosine phosphorylation or downstream signaling in any detectable way, suggesting that T794 phosphorylation may regulate a Tie1 function independent of its RTK properties. Although T794 is within a consensus Akt phosphorylation site, we were unable to identify a physiological activator of Akt that could induce T794 phosphorylation, suggesting that Akt is not the physiological Tie1-T794 kinase. However, the small GTPase Ras-related C3 botulinum toxin substrate 1 (Rac1), which is required for angiogenesis and capillary morphogenesis, was found to associate with phospho-T794 but not the non-phosphorylatable T794A mutant. Pharmacological activation of Rac1 induced downstream activation of p21-activated kinase (PAK1) and T794 phosphorylation in vitro, and inhibition of PAK1 abrogated T794 phosphorylation. Our results provide the first demonstration of a signaling pathway mediated by Tie1 in endothelial cells, and they suggest that a novel feedback loop involving Rac1/PAK1 mediated phosphorylation of Tie1 on T794 is required for proper angiogenesis. PMID:26436659

  8. MicroRNA-429 inhibits the migration and invasion of colon cancer cells by targeting PAK6/cofilin signaling.

    PubMed

    Tian, Xiangyang; Wei, Zibai; Wang, Jia; Liu, Ping; Qin, Yijun; Zhong, Meizuo

    2015-08-01

    MicroRNAs (miRs), a class of non-coding RNAs 18-25 nucleotides in length, can lead to mRNA degradation or inhibit protein translation by directly binding to the 3'-untranslational region (UTR) of their target mRNAs. The deregulation of miR-429 has been suggested to be involved in the development and progression of colon cancer. However, the detailed molecular mechanism involved remains to be determined. The aim of the present study was to investigate the role of miR-429 in the regulation of migration and invasion of colon cancer cells using RT-qPCR and western blotting. The results showed that the expression of miR-429 was reduced in colon cancer cell lines, when compared to a normal colon epithelial cell line. Treatment with DNA demethylation agent 5-aza-2'-deoxycytidine and histone deacetylase inhibitor phenylbutyrate (PBA), or transfection with the pre-miR-429 lentivirus plasmid led to the upregulation of miR-429 expression, as well as inhibition of migration and invasion in colon cancer cells. Investigation of the molecular mechanism showed that PAK6 was a novel target of miR-429, and the expression of PAK6 was upregulated in colon cancer tissues and cell lines, and was negatively regulated by miR-429 in colon cancer cells. Moreover, the cofilin signaling acted as a downstream effector of miR-429 in colon cancer cells. In conclusion, the results of the present study suggested that miR-429 inhibits the migration and invasion of colon cancer cells, partly at least, by mediating the expression of PAK6, as well as the activity of cofilin signaling. Therefore, miR-429 is as a potential molecular target for the treatment of colon cancer. PMID:26058485

  9. Leveraging the Pre-DFG Residue Thr-406 To Obtain High Kinase Selectivity in an Aminopyrazole-Type PAK1 Inhibitor Series.

    PubMed

    Rudolph, Joachim; Aliagas, Ignacio; Crawford, James J; Mathieu, Simon; Lee, Wendy; Chao, Qi; Dong, Ping; Rouge, Lionel; Wang, Weiru; Heise, Christopher; Murray, Lesley J; La, Hank; Liu, Yanzhou; Manning, Gerard; Diederich, François; Hoeflich, Klaus P

    2015-06-11

    To increase kinase selectivity in an aminopyrazole-based PAK1 inhibitor series, analogues were designed to interact with the PAK1 deep-front pocket pre-DFG residue Thr-406, a residue that is hydrophobic in most kinases. This goal was achieved by installing lactam head groups to the aminopyrazole hinge binding moiety. The corresponding analogues represent the most kinase selective ATP-competitive Group I PAK inhibitors described to date. Hydrogen bonding with the Thr-406 side chain was demonstrated by X-ray crystallography, and inhibitory activities, particularly against kinases with hydrophobic pre-DFG residues, were mitigated. Leveraging hydrogen bonding side chain interactions with polar pre-DFG residues is unprecedented, and similar strategies should be applicable to other appropriate kinases. PMID:26101579

  10. Comparison of Peritoneal Adhesion Formation in Bowel Retraction by Cotton Towels Versus the Silicone Lap Pak Device in a Rabbit Model

    PubMed Central

    Liu, Brian G.; Ruben, Dawn S.; Renz, Wolfgang; Santillan, Antonio; Kubisen, Steven J.; Harmon, John W.

    2011-01-01

    Objective: Manipulation of cotton operating room towels within the abdominal cavity in open abdominal surgery has been associated with the formation of peritoneal adhesions. In a rabbit model, the use of standard cotton operating room towels is compared to the Lap Pak, a silicone bowel-packing device, to determine the potential for reducing the risk of adhesions. Methods: Thirty rabbits were randomly assigned to 3 groups. The rabbits underwent a sham surgery with incision only (n = 10), placement of operating room towels (n = 10), or placement of a Lap Pak (n = 10). After 14 days, the rabbits were sacrificed and the peritoneal cavity explored for adhesions. The number, tenacity, ease of dissection, and density of adhesions were recorded, and the adhesions quantitatively graded using a Modified Hopkins Adhesion scoring system. Results: The operating room towel group had an average adhesion score of 2.5, and 8 (80%) rabbits developed adhesions. The sham group had an average adhesion score of 0.3 and one rabbit (10%) developed adhesions. The Lap Pak group had an average adhesion score of 0.2 and 1 rabbit (10%) developed adhesions. The frequency and severity of adhesions in the operating room towel group were significantly greater from that of the baseline sham group. There was no significant difference between the Lap Pak and sham groups. Conclusions: In this rabbit laparotomy model, the use of the Lap Pak to retract the bowels resulted in significantly fewer adhesions compared to cotton operating room towels. Lap Pak may be beneficial for bowel packing in general abdominal surgeries. PMID:22096614

  11. Molluscan associations from the Pak Phanang Bay (SW Gulf of Thailand) as a record of natural and anthropogenic changes

    NASA Astrophysics Data System (ADS)

    Negri, Mauro Pietro; Sanfilippo, Rossana; Basso, Daniela; Rosso, Antonietta; Di Geronimo, Sebastiano Italo

    2014-08-01

    Recent environmental changes in the Pak Phanang Bay (SW Gulf of Thailand) are investigated by means of mollusc assemblages. The present-day water depth within the bay slightly exceeds 2 m at low tide and the seafloor is almost entirely muddy, except for the outermost part of the embayment which is directly influenced by the longshore drift that is building the Laem Talumpuk sand spit. A multivariate analysis of the molluscan fauna recovered at 16 sampling stations within the bay delineates three thanatofacies and two biofacies. The Bay Mouth thanatofacies, including several infralittoral species, is distributed around the bay entrance; the Tidal Flat thanatofacies, characterized by few brackish and freshwater taxa, occurs in the inner part of the bay; the Channel thanatofacies includes a mixed fauna and is found along the long axis of the bay. All thanatofacies are not older than a few decades. The two biofacies are significantly less diverse than their dead counterparts, and are simply identified as Bay Mouth biofacies and Inner Bay biofacies. The faunal evolution, combined with bathymetric and sedimentological data, confirms that the embayment is undergoing a confinement process. The inner bay has evolved into an undifferentiated tidal flat hosting an oligospecific fauna. The confinement trend and the consequent siltation of the bay, mainly due to natural geomorphologic processes acting since centuries, are likely to have sped up in recent years by interaction with some human activities; among these, the deforestation in the upper Pak Phanang basin and the construction of Uthokaviphatprasit Watergate.

  12. PrimaTB STAT-PAK Assay, a Novel, Rapid Lateral-Flow Test for Tuberculosis in Nonhuman Primates▿

    PubMed Central

    Lyashchenko, Konstantin P.; Greenwald, Rena; Esfandiari, Javan; Greenwald, David; Nacy, Carol A.; Gibson, Susan; Didier, Peter J.; Washington, Marc; Szczerba, Peter; Motzel, Sherri; Handt, Larry; Pollock, John M.; McNair, James; Andersen, Peter; Langermans, Jan A. M.; Verreck, Frank; Ervin, Sean; Ervin, Frank; McCombs, Candace

    2007-01-01

    Tuberculosis (TB) is the most important zoonotic bacterial disease in nonhuman primates (NHP). The current diagnostic method, the intradermal palpebral tuberculin test, has serious shortcomings. We characterized antibody responses in NHP against Mycobacterium tuberculosis to identify immunodominant antigens and develop a rapid serodiagnostic test for TB. A total of 422 NHP were evaluated, including 243 rhesus (Macaca mulatta), 46 cynomolgus (Macaca fascicularis), and 133 African green (Cercopithecus aethiops sabaeus) monkeys at five collaborative centers. Of those, 50 monkeys of the three species were experimentally inoculated with M. tuberculosis. Antibody responses were monitored every 2 to 4 weeks for up to 8 months postinfection by MultiAntigen Print ImmunoAssay with a panel of 12 recombinant antigens. All of the infected monkeys produced antibodies at various levels and with different antigen recognition patterns. ESAT-6 and MPB83 were the most frequently recognized proteins during infection. A combination of selected antigens which detected antibodies in all of the infected monkeys was designed to develop the PrimaTB STAT-PAK assay by lateral-flow technology. Serological evaluation demonstrated high diagnostic sensitivity (90%) and specificity (99%). The highest rate of TB detection was achieved when the skin test was combined with the PrimaTB STAT-PAK kit. This novel immunoassay provides a simple, rapid, and accurate test for TB in NHP. PMID:17652522

  13. [Life and medical missionary activities of Esther K. Pak (1877-1910)].

    PubMed

    Lee, Bang Weon

    2007-12-01

    Esther K. Pak (1876-1910) is believed as the first medical doctor in Korea. Esther's life can be largely reviewed in three parts: school-hood at EwhaHaktang (currently Ewha Womans University), Education in the United States, and medical missionary work after coming back to Korea from the United States. The foreign Methodist missionaries was able to enter Korea after opening of its ports and establishing its diplomatic relationship with the United States. Esther met modern sciences and Christianity at EwhaHaktang, which was founded by those missionaries. She could dream of being an American-style medical doctor in the future, while she assisted medical missionaries at PoKuNyoKwan in EwhaHaktang. She could get substantial academic help from those missionaries. With the support of Dr. Rosetta Sherwood Hall, who first introduced the world of medial science to Esther in a real sense, Esther went to the United States to study the field in 1894. While learning it, she suffered from academic frustration, economic difficulty, her husband's death and so on, but she eventually got over those adversities and completed the four years of academic courses to become a medical doctor. Her religious faith and will to help Koreans as a doctor encouraged her to finish what she had originally planned. Esther came back to Korea in 1900 and began to work earnestly as a medical missionary delegated from Woman's Foreign Missionary Society. At PoKuNyoKwan in Seoul and Woman's Hospital in Pyongyang, She performed medical work and enlightenment campaign against the superstitious healing conduct. Esther also took part in the circuit missionary performances. She devoted herself for evangelical work at Bible Institute as well. Esther's activity made people understand the effectiveness of education. She helped people to recognize education for woman, occidental medical treatment and Christianity in a positive way. On April 28, 1909, based on these excellent performances for the social development

  14. Glucosinolate Accumulation and Related Gene Expression in Pak Choi (Brassica rapa L. ssp. chinensis var. communis [N. Tsen & S.H. Lee] Hanelt) in Response to Insecticide Application.

    PubMed

    Zhu, Biao; Yang, Jing; He, Yong; Zang, Yunxiang; Zhu, Zhujun

    2015-11-11

    Glucosinolates and their breakdown products are well-known for their cancer-chemoprotective functions and biocidal activities against pathogens and generalist herbivores. Insecticides are commonly used in the production of pak choi (Brassica rapa L. ssp. chinensis var. communis [N. Tsen & S.H. Lee] Hanelt). We studied the effects of four commonly used insecticides, namely, β-cypermethrin, acephate, pymetrozine, and imidacloprid, on glucosinolate metabolism in pak choi. All insecticides significantly increased both the transcription of glucosinolate biosynthetic genes and the aliphatic and total glucosinolate accumulations in pak choi. β-Cypermethrin and acephate caused gradual and continuous up-regulation of gene expression from 0.5 to 24 h after treatment, whereas pymetrozine and imidacloprid did so more rapidly, reaching a peak at 1 h and returning to normal at 3 h. Our findings indicate that the four insecticides affect glucosinolate metabolism in pak choi plants to various degrees and suggest that glucosinolates may be involved in plant insecticide metabolism. PMID:26485123

  15. ETV TEST REPORT OF CONTROL OF BIOAEROSOLS IN HVAC SYSTEMS GLASFLOSS INDUSTRIES Z-PAK SERIES S, MODEL ZPS24241295BO

    EPA Science Inventory

    The Environmental Technology Verification report discusses the technology and performance of the Z-Pak Series S, Model ZPS24241295B0 air filter for dust and bioaerosol filtration manufactured by Glasfloss Industries, Inc. The pressure drop across the filter was 91 Pa clean and 34...

  16. A Population Growth Trend Analysis for Neotricula aperta, the Snail Intermediate Host of Schistosoma mekongi, after Construction of the Pak-Mun Dam

    PubMed Central

    Attwood, Stephen W.; Upatham, E. Suchart

    2013-01-01

    Background The Pak-Mun dam is a controversial hydro-power project on the Mun River in Northeast Thailand. The dam is sited in a habitat of the freshwater snail Neotricula aperta, which is the intermediate host for the parasitic blood-fluke Schistosoma mekongi causing Mekong schistosomiasis in humans in Cambodia and Laos. Few data are available which can be used to assess the effects of water resource development on N. aperta. The aim of this study was to obtain data and to analyze the possible impact of the dam on N. aperta population growth. Methodology/Principal Findings Estimated population densities were recorded for an N. aperta population in the Mun River 27 km upstream of Pak-Mun, from 1990 to 2011. The Pak-Mul dam began to operate in 1994. Population growth was modeled using a linear mixed model expression of a modified Gompertz stochastic state-space exponential growth model. The N. aperta population was found to be quite stable, with the estimated growth parameter not significantly different from zero. Nevertheless, some marked changes in snail population density were observed which were coincident with changes in dam operation policy. Conclusions/Significance The study found that there has been no marked increase in N. aperta population growth following operation of the Pak-Mun dam. The analysis did indicate a large and statistically significant increase in population density immediately after the dam came into operation; however, this increase was not persistent. The study has provided the first vital baseline data on N. aperta population behavior near to the Pak-Mun dam and suggests that the operation policy of the dam may have an impact on snail population density. Nevertheless, additional studies are required for other N. aperta populations in the Mun River and for an extended time series, to confirm or refine the findings of this work. PMID:24244775

  17. Molecular evolution, characterization, and expression analysis of SnRK2 gene family in Pak-choi (Brassica rapa ssp. chinensis)

    PubMed Central

    Huang, Zhinan; Tang, Jun; Duan, Weike; Wang, Zhen; Song, Xiaoming; Hou, Xilin

    2015-01-01

    The sucrose non-fermenting 1-related protein kinase 2 (SnRK2) family members are plant-specific serine/threonine kinases that are involved in the plant response to abiotic stress and abscisic acid (ABA)-dependent plant development. Further understanding of the evolutionary history and expression characteristics of these genes will help to elucidate the mechanisms of the stress tolerance in Pak-choi, an important green leafy vegetable in China. Thus, we investigated the evolutionary patterns, footprints and conservation of SnRK2 genes in selected plants and later cloned and analyzed SnRK2 genes in Pak-choi. We found that this gene family was preferentially retained in Brassicas after the Brassica-Arabidopsis thaliana split. Next, we cloned and sequenced 13 SnRK2 from both cDNA and DNA libraries of stress-induced Pak-choi, which were under conditions of ABA, salinity, cold, heat, and osmotic treatments. Most of the BcSnRK2s have eight exons and could be divided into three groups. The subcellular localization predictions suggested that the putative BcSnRK2 proteins were enriched in the nucleus. The results of an analysis of the expression patterns of the BcSnRK2 genes showed that BcSnRK2 group III genes were robustly induced by ABA treatments. Most of the BcSnRK2 genes were activated by low temperature, and the BcSnRK2.6 genes responded to both ABA and low temperature. In fact, most of the BcSnRK2 genes showed positive or negative regulation under ABA and low temperature treatments, suggesting that they may be global regulators that function at the intersection of multiple signaling pathways to play important roles in Pak-choi stress responses. PMID:26557127

  18. FTY720 prevents ischemia/reperfusion injury-associated arrhythmias in an ex vivo rat heart model via activation of Pak1/Akt signaling.

    PubMed

    Egom, E Eroume A; Ke, Yunbo; Musa, Hanny; Mohamed, Tamer M A; Wang, Tao; Cartwright, Elizabeth; Solaro, R John; Lei, Ming

    2010-02-01

    Recent studies demonstrated a role of sphingosine-1-phosphate (S1P) in the protection against the stress of ischemia/reperfusion (I/R) injury. In experiments reported here, we have investigated the signaling through the S1P cascade by FTY720, a sphingolipid drug candidate displaying structural similarity to S1P, underlying the S1P cardioprotective effect. In ex vivo rat heart and isolated sinoatrial node models, FTY720 significantly prevented arrhythmic events associated with I/R injury including premature ventricular beats, VT, and sinus bradycardia as well as A-V conduction block. Real-time PCR and Western blot analysis demonstrated the expression of the S1P receptor transcript pools and corresponding proteins including S1P1, S1P2, and S1P3 in tissues dissected from sinoatrial node, atrium and ventricle. FTY720 (25 nM) significantly blunted the depression of the levels of phospho-Pak1 and phospho-Akt with ischemia and with reperfusion. There was a significant increase in phospho-Pak1 levels by 35%, 199%, and 205% after 5, 10, and 15 min of treatment with 25 nM FTY720 compared with control nontreated myocytes. However, there was no significant difference in the levels of total Pak1 expression between nontreated and FTY720 treated. Phospho-Akt levels were increased by 44%, 63%, and 61% after 5, 10, and 15 min of treatment with 25 nM FTY720, respectively. Our data provide the first evidence that FTY720 prevents I/R injury-associated arrhythmias and indicate its potential significance as an important and new agent protecting against I/R injury. Our data also indicate, for the first time, that the cardioprotective effect of FTY720 is likely to involve activation of signaling through the Pak1. PMID:19852968

  19. Molecular evolution, characterization, and expression analysis of SnRK2 gene family in Pak-choi (Brassica rapa ssp. chinensis).

    PubMed

    Huang, Zhinan; Tang, Jun; Duan, Weike; Wang, Zhen; Song, Xiaoming; Hou, Xilin

    2015-01-01

    The sucrose non-fermenting 1-related protein kinase 2 (SnRK2) family members are plant-specific serine/threonine kinases that are involved in the plant response to abiotic stress and abscisic acid (ABA)-dependent plant development. Further understanding of the evolutionary history and expression characteristics of these genes will help to elucidate the mechanisms of the stress tolerance in Pak-choi, an important green leafy vegetable in China. Thus, we investigated the evolutionary patterns, footprints and conservation of SnRK2 genes in selected plants and later cloned and analyzed SnRK2 genes in Pak-choi. We found that this gene family was preferentially retained in Brassicas after the Brassica-Arabidopsis thaliana split. Next, we cloned and sequenced 13 SnRK2 from both cDNA and DNA libraries of stress-induced Pak-choi, which were under conditions of ABA, salinity, cold, heat, and osmotic treatments. Most of the BcSnRK2s have eight exons and could be divided into three groups. The subcellular localization predictions suggested that the putative BcSnRK2 proteins were enriched in the nucleus. The results of an analysis of the expression patterns of the BcSnRK2 genes showed that BcSnRK2 group III genes were robustly induced by ABA treatments. Most of the BcSnRK2 genes were activated by low temperature, and the BcSnRK2.6 genes responded to both ABA and low temperature. In fact, most of the BcSnRK2 genes showed positive or negative regulation under ABA and low temperature treatments, suggesting that they may be global regulators that function at the intersection of multiple signaling pathways to play important roles in Pak-choi stress responses. PMID:26557127

  20. Phytoavailability of Cadmium (Cd) to Pak Choi (Brassica chinensis L.) Grown in Chinese Soils: A Model to Evaluate the Impact of Soil Cd Pollution on Potential Dietary Toxicity

    PubMed Central

    Yang, Xiaoe; Xiao, Wendan; Stoffella, Peter J.; Saghir, Aamir; Azam, Muhammad; Li, Tingqiang

    2014-01-01

    Food chain contamination by soil cadmium (Cd) through vegetable consumption poses a threat to human health. Therefore, an understanding is needed on the relationship between the phytoavailability of Cd in soils and its uptake in edible tissues of vegetables. The purpose of this study was to establish soil Cd thresholds of representative Chinese soils based on dietary toxicity to humans and develop a model to evaluate the phytoavailability of Cd to Pak choi (Brassica chinensis L.) based on soil properties. Mehlich-3 extractable Cd thresholds were more suitable for Stagnic Anthrosols, Calcareous, Ustic Cambosols, Typic Haplustalfs, Udic Ferrisols and Periudic Argosols with values of 0.30, 0.25, 0.18, 0.16, 0.15 and 0.03 mg kg−1, respectively, while total Cd is adequate threshold for Mollisols with a value of 0.86 mg kg−1. A stepwise regression model indicated that Cd phytoavailability to Pak choi was significantly influenced by soil pH, organic matter, total Zinc and Cd concentrations in soil. Therefore, since Cd accumulation in Pak choi varied with soil characteristics, they should be considered while assessing the environmental quality of soils to ensure the hygienically safe food production. PMID:25386790

  1. Prostasin may contribute to chemoresistance, repress cancer cells in ovarian cancer, and is involved in the signaling pathways of CASP/PAK2-p34/actin.

    PubMed

    Yan, B-x; Ma, J-x; Zhang, J; Guo, Y; Mueller, M D; Remick, S C; Yu, J J

    2014-01-01

    Ovarian cancer is the deadliest of gynecologic cancers, largely due to the development of drug resistance in chemotherapy. Prostasin may have an essential role in the oncogenesis. In this study, we show that prostasin is decreased in an ovarian cancer drug-resistant cell line and in ovarian cancer patients with high levels of excision repair cross-complementing 1, a marker for chemoresistance. Our cell cultural model investigation demonstrates prostasin has important roles in the development of drug resistance and cancer cell survival. Forced overexpression of prostasin in ovarian cancer cells greatly induces cell death (resulting in 99% cell death in a drug-resistant cell line and 100% cell death in other tested cell lines). In addition, the surviving cells grow at a much lower rate compared with non-overexpressed cells. In vivo studies indicate that forced overexpression of prostasin in drug-resistant cells greatly inhibits the growth of tumors and may partially reverse drug resistance. Our investigation of the molecular mechanisms suggests that prostasin may repress cancer cells and/or contribute to chemoresistance by modulating the CASP/P21-activated protein kinase (PAK2)-p34 pathway, and thereafter PAK2-p34/JNK/c-jun and PAK2-p34/mlck/actin signaling pathways. Thus, we introduce prostain as a potential target for treating/repressing some ovarian tumors and have begun to identify their relevant molecular targets in specific signaling pathways. PMID:24434518

  2. Prostasin may contribute to chemoresistance, repress cancer cells in ovarian cancer, and is involved in the signaling pathways of CASP/PAK2-p34/actin

    PubMed Central

    Yan, B-x; Ma, J-x; Zhang, J; Guo, Y; Mueller, M D; Remick, S C; Yu, J J

    2014-01-01

    Ovarian cancer is the deadliest of gynecologic cancers, largely due to the development of drug resistance in chemotherapy. Prostasin may have an essential role in the oncogenesis. In this study, we show that prostasin is decreased in an ovarian cancer drug-resistant cell line and in ovarian cancer patients with high levels of excision repair cross-complementing 1, a marker for chemoresistance. Our cell cultural model investigation demonstrates prostasin has important roles in the development of drug resistance and cancer cell survival. Forced overexpression of prostasin in ovarian cancer cells greatly induces cell death (resulting in 99% cell death in a drug-resistant cell line and 100% cell death in other tested cell lines). In addition, the surviving cells grow at a much lower rate compared with non-overexpressed cells. In vivo studies indicate that forced overexpression of prostasin in drug-resistant cells greatly inhibits the growth of tumors and may partially reverse drug resistance. Our investigation of the molecular mechanisms suggests that prostasin may repress cancer cells and/or contribute to chemoresistance by modulating the CASP/P21-activated protein kinase (PAK2)-p34 pathway, and thereafter PAK2-p34/JNK/c-jun and PAK2-p34/mlck/actin signaling pathways. Thus, we introduce prostain as a potential target for treating/repressing some ovarian tumors and have begun to identify their relevant molecular targets in specific signaling pathways. PMID:24434518

  3. Glutamine nitrogen and ammonium nitrogen supplied as a nitrogen source is not converted into nitrate nitrogen of plant tissues of hydroponically grown pak-choi (Brassica chinensis L.).

    PubMed

    Wang, H-J; Wu, L-H; Tao, Q-N; Miller, D D; Welch, R M

    2009-03-01

    Many vegetables, especially leafy vegetables, accumulate NO(-) (3)-N in their edible portions. High nitrate levels in vegetables constitute a health hazard, such as cancers and blue baby syndrome. The aim of this study was to determine if (1) ammonium nitrogen (NH(+) (4)-N) and glutamine-nitrogen (Gln-N) absorbed by plant roots is converted into nitrate-nitrogen of pak-choi (Brassica chinensis L.) tissues, and (2) if nitrate-nitrogen (NO(-) (3)-N) accumulation and concentration of pak-choi tissues linearly increase with increasing NO(-) (3)-N supply when grown in nutrient solution. In experiment 1, 4 different nitrogen treatments (no nitrogen, NH(+) (4)-N, Gln-N, and NO(-) (3)-N) with equal total N concentrations in treatments with added N were applied under sterile nutrient medium culture conditions. In experiment 2, 5 concentrations of N (from 0 to 48 mM), supplied as NO(-) (3)-N in the nutrient solution, were tested. The results showed that Gln-N and NH(+) (4)-N added to the nutrient media were not converted into nitrate-nitrogen of plant tissues. Also, NO(-) (3)-N accumulation in the pak-choi tissues was the highest when plants were supplied 24 mM NO(-) (3)-N in the media. The NO(-) (3)-N concentration in plant tissues was quadratically correlated to the NO(-) (3)-N concentration supplied in the nutrient solution. PMID:19323774

  4. Phytoavailability of cadmium (Cd) to Pak choi (Brassica chinensis L.) grown in Chinese soils: a model to evaluate the impact of soil Cd pollution on potential dietary toxicity.

    PubMed

    Rafiq, Muhammad Tariq; Aziz, Rukhsanda; Yang, Xiaoe; Xiao, Wendan; Stoffella, Peter J; Saghir, Aamir; Azam, Muhammad; Li, Tingqiang

    2014-01-01

    Food chain contamination by soil cadmium (Cd) through vegetable consumption poses a threat to human health. Therefore, an understanding is needed on the relationship between the phytoavailability of Cd in soils and its uptake in edible tissues of vegetables. The purpose of this study was to establish soil Cd thresholds of representative Chinese soils based on dietary toxicity to humans and develop a model to evaluate the phytoavailability of Cd to Pak choi (Brassica chinensis L.) based on soil properties. Mehlich-3 extractable Cd thresholds were more suitable for Stagnic Anthrosols, Calcareous, Ustic Cambosols, Typic Haplustalfs, Udic Ferrisols and Periudic Argosols with values of 0.30, 0.25, 0.18, 0.16, 0.15 and 0.03 mg kg-1, respectively, while total Cd is adequate threshold for Mollisols with a value of 0.86 mg kg-1. A stepwise regression model indicated that Cd phytoavailability to Pak choi was significantly influenced by soil pH, organic matter, total Zinc and Cd concentrations in soil. Therefore, since Cd accumulation in Pak choi varied with soil characteristics, they should be considered while assessing the environmental quality of soils to ensure the hygienically safe food production. PMID:25386790

  5. Separation properties of aluminium-plastic laminates in post-consumer Tetra Pak with mixed organic solvent.

    PubMed

    Zhang, S F; Zhang, L L; Luo, K; Sun, Z X; Mei, X X

    2014-04-01

    The separation properties of the aluminium-plastic laminates in postconsumer Tetra Pak structure were studied in this present work. The organic solvent blend of benzene-ethyl alcohol-water was used as the separation reagent. Then triangle coordinate figure analysis was taken to optimize the volume proportion of various components in the separating agent and separation process. And the separation temperature of aluminium-plastic laminates was determined by the separation time, efficiency, and total mass loss of products. The results show that cost-efficient separations perform best with low usage of solvents at certain temperatures, for certain times, and within a certain range of volume proportions of the three components in the solvent agent. It is also found that similar solubility parameters of solvents and polyethylene adhesives (range 26.06-34.85) are a key factor for the separation of the aluminium-plastic laminates. Such multisolvent processes based on the combined-system concept will be vital to applications in the recycling industry. PMID:24622294

  6. Environment. [Project ECOLogy ELE Pak, Dorland Pak].

    ERIC Educational Resources Information Center

    Dorland, Billie

    This is one of a series of units for environmental education developed by the Highline Public Schools. This unit, which focuses on environment and ecology, is designed for upper grade elementary school pupils. Since the five lessons were designed specifically for substitute teachers, each is completely self-contained. Each lesson is developed in…

  7. p21-Activated kinase 2 (PAK2) inhibits TGF-β signaling in Madin-Darby canine kidney (MDCK) epithelial cells by interfering with the receptor-Smad interaction.

    PubMed

    Yan, Xiaohua; Zhang, Junyu; Sun, Qinyu; Tuazon, Polygena T; Wu, Xiaoping; Traugh, Jolinda A; Chen, Ye-Guang

    2012-04-20

    TGF-β (transforming growth factor β) plays a variety of cellular functions mainly through the Smad pathway. Phosphorylation of the carboxyl SXS motif in R-Smads (Smad2 and Smad3) by the type I receptor TβRI is a key step for their activation. It has been reported that the serine/threonine kinase PAK2 (p21-activated kinase 2) can mediate TGF-β signaling in mesenchymal cells. Here, we report that PAK2 restricts TGF-β-induced Smad2/3 activation and transcriptional responsiveness in MDCK epithelial cells. Mechanistically, PAK2 associates with Smad2 and Smad3 in a kinase activity-dependent manner and blocks their activation. PAK2 phosphorylates Smad2 at Ser-417, which is adjacent to the L3 loop that contributes to the TβRI-R-Smad association. Consistently, substitution of Ser-417 with glutamic acid attenuates the interaction of Smad2 with TβRI. Together, our results indicate that PAK2 negatively modulate TGF-β signaling by attenuating the receptor-Smad interaction and thus Smad activation. PMID:22393057

  8. Liposome reconstitution and modulation of recombinant prenylated human Rac1 by GEFs, GDI1 and Pak1.

    PubMed

    Zhang, Si-Cai; Gremer, Lothar; Heise, Henrike; Janning, Petra; Shymanets, Aliaksei; Cirstea, Ion C; Krause, Eberhard; Nürnberg, Bernd; Ahmadian, Mohammad Reza

    2014-01-01

    Small Rho GTPases are well known to regulate a variety of cellular processes by acting as molecular switches. The regulatory function of Rho GTPases is critically dependent on their posttranslational modification at the carboxyl terminus by isoprenylation and association with proper cellular membranes. Despite numerous studies, the mechanisms of recycling and functional integration of Rho GTPases at the biological membranes are largely unclear. In this study, prenylated human Rac1, a prominent member of the Rho family, was purified in large amount from baculovirus-infected Spodoptera frugiperda insect cells using a systematic detergent screening. In contrast to non-prenylated human Rac1 purified from Escherichia coli, prenylated Rac1 from insect cells was able to associate with synthetic liposomes and to bind Rho-specific guanine nucleotide dissociation inhibitor 1 (GDI1). Subsequent liposome reconstitution experiments revealed that GDI1 efficiently extracts Rac1 from liposomes preferentially in the inactive GDP-bound state. The extraction was prevented when Rac1 was activated to its GTP-bound state by Rac-specific guanine nucleotide exchange factors (GEFs), such as Vav2, Dbl, Tiam1, P-Rex1 and TrioN, and bound by the downstream effector Pak1. We found that dissociation of Rac1-GDP from its complex with GDI1 strongly correlated with two distinct activities of especially Dbl and Tiam1, including liposome association and the GDP/GTP exchange. Taken together, our results provided first detailed insights into the advantages of the in vitro liposome-based reconstitution system to study both the integration of the signal transducing protein complexes and the mechanisms of regulation and signaling of small GTPases at biological membranes. PMID:25014207

  9. Liposome Reconstitution and Modulation of Recombinant Prenylated Human Rac1 by GEFs, GDI1 and Pak1

    PubMed Central

    Zhang, Si-Cai; Gremer, Lothar; Heise, Henrike; Janning, Petra; Shymanets, Aliaksei; Cirstea, Ion C.; Krause, Eberhard; Nürnberg, Bernd; Ahmadian, Mohammad Reza

    2014-01-01

    Small Rho GTPases are well known to regulate a variety of cellular processes by acting as molecular switches. The regulatory function of Rho GTPases is critically dependent on their posttranslational modification at the carboxyl terminus by isoprenylation and association with proper cellular membranes. Despite numerous studies, the mechanisms of recycling and functional integration of Rho GTPases at the biological membranes are largely unclear. In this study, prenylated human Rac1, a prominent member of the Rho family, was purified in large amount from baculovirus-infected Spodoptera frugiperda insect cells using a systematic detergent screening. In contrast to non-prenylated human Rac1 purified from Escherichia coli, prenylated Rac1 from insect cells was able to associate with synthetic liposomes and to bind Rho-specific guanine nucleotide dissociation inhibitor 1 (GDI1). Subsequent liposome reconstitution experiments revealed that GDI1 efficiently extracts Rac1 from liposomes preferentially in the inactive GDP-bound state. The extraction was prevented when Rac1 was activated to its GTP-bound state by Rac-specific guanine nucleotide exchange factors (GEFs), such as Vav2, Dbl, Tiam1, P-Rex1 and TrioN, and bound by the downstream effector Pak1. We found that dissociation of Rac1-GDP from its complex with GDI1 strongly correlated with two distinct activities of especially Dbl and Tiam1, including liposome association and the GDP/GTP exchange. Taken together, our results provided first detailed insights into the advantages of the in vitro liposome-based reconstitution system to study both the integration of the signal transducing protein complexes and the mechanisms of regulation and signaling of small GTPases at biological membranes. PMID:25014207

  10. An inherited duplication at the gene p21 Protein-Activated Kinase 7 (PAK7) is a risk factor for psychosis.

    PubMed

    Morris, Derek W; Pearson, Richard D; Cormican, Paul; Kenny, Elaine M; O'Dushlaine, Colm T; Perreault, Louis-Philippe Lemieux; Giannoulatou, Eleni; Tropea, Daniela; Maher, Brion S; Wormley, Brandon; Kelleher, Eric; Fahey, Ciara; Molinos, Ines; Bellini, Stefania; Pirinen, Matti; Strange, Amy; Freeman, Colin; Thiselton, Dawn L; Elves, Rachel L; Regan, Regina; Ennis, Sean; Dinan, Timothy G; McDonald, Colm; Murphy, Kieran C; O'Callaghan, Eadbhard; Waddington, John L; Walsh, Dermot; O'Donovan, Michael; Grozeva, Detelina; Craddock, Nick; Stone, Jennifer; Scolnick, Ed; Purcell, Shaun; Sklar, Pamela; Coe, Bradley; Eichler, Evan E; Ophoff, Roel; Buizer, Jacobine; Szatkiewicz, Jin; Hultman, Christina; Sullivan, Patrick; Gurling, Hugh; Mcquillin, Andrew; St Clair, David; Rees, Elliott; Kirov, George; Walters, James; Blackwood, Douglas; Johnstone, Mandy; Donohoe, Gary; O'Neill, Francis A; Kendler, Kenneth S; Gill, Michael; Riley, Brien P; Spencer, Chris C A; Corvin, Aiden

    2014-06-15

    Identifying rare, highly penetrant risk mutations may be an important step in dissecting the molecular etiology of schizophrenia. We conducted a gene-based analysis of large (>100 kb), rare copy-number variants (CNVs) in the Wellcome Trust Case Control Consortium 2 (WTCCC2) schizophrenia sample of 1564 cases and 1748 controls all from Ireland, and further extended the analysis to include an additional 5196 UK controls. We found association with duplications at chr20p12.2 (P = 0.007) and evidence of replication in large independent European schizophrenia (P = 0.052) and UK bipolar disorder case-control cohorts (P = 0.047). A combined analysis of Irish/UK subjects including additional psychosis cases (schizophrenia and bipolar disorder) identified 22 carriers in 11 707 cases and 10 carriers in 21 204 controls [meta-analysis Cochran-Mantel-Haenszel P-value = 2 × 10(-4); odds ratio (OR) = 11.3, 95% CI = 3.7, ∞]. Nineteen of the 22 cases and 8 of the 10 controls carried duplications starting at 9.68 Mb with similar breakpoints across samples. By haplotype analysis and sequencing, we identified a tandem ~149 kb duplication overlapping the gene p21 Protein-Activated Kinase 7 (PAK7, also called PAK5) which was in linkage disequilibrium with local haplotypes (P = 2.5 × 10(-21)), indicative of a single ancestral duplication event. We confirmed the breakpoints in 8/8 carriers tested and found co-segregation of the duplication with illness in two additional family members of one of the affected probands. We demonstrate that PAK7 is developmentally co-expressed with another known psychosis risk gene (DISC1) suggesting a potential molecular mechanism involving aberrant synapse development and plasticity. PMID:24474471

  11. Overexpressed Down Syndrome Cell Adhesion Molecule (DSCAM) Deregulates P21-Activated Kinase (PAK) Activity in an In Vitro Neuronal Model of Down Syndrome: Consequences on Cell Process Formation and Extension.

    PubMed

    Pérez-Núñez, Ramón; Barraza, Natalia; Gonzalez-Jamett, Arlek; Cárdenas, Ana Maria; Barnier, Jean-Vianney; Caviedes, Pablo

    2016-07-01

    In humans, Down syndrome (DS) is caused by the presence of an extra copy of autosome 21. The most striking finding in DS patients is intellectual disability and the onset of Alzheimer's disease (AD)-like neuropathology in adulthood. Gene overdose is most likely to underlie both developmental impairments, as well as altered neuronal function in DS. Lately, the disruption of cellular signaling and regulatory pathways has been implicated in DS pathophysiology, and many of such pathways may represent common targets for diverse DS-related genes, which could in turn represent attractive therapeutical targets. In this regard, one DS-related gene Down Syndrome Cell Adhesion Molecule (DSCAM), has important functions in neuronal proliferation, maturation, and synaptogenesis. p21-associated kinases (PAKs) appear as a most interesting possibility for study, as DSCAM is known to regulate the PAKs pathway. Hence, in DS, overexpressed DSCAM could deregulate PAKs activity and affect signaling pathways that regulate synaptic plasticity such as dendritic spine dynamics and axon guidance and growth. In the present work, we used an immortalized cell line derived from the cerebral cortex of an animal model of DS such as the trisomy 16 (Ts16) fetal mouse (named CTb), and a similar cell line established from a normal littermate (named CNh), to study the effect of DSCAM in the PAKs pathway. The present study shows that DSCAM is overexpressed in CTb cells by approximately twofold, compared to CNh cells. Congruently, PAK1, as well as its downstream effectors LIMK and cofilin, stay phosphorylated for longer periods after DSCAM activation in the CTb cells, leading to an altered actin dynamics, expressed as an increased basal F/G ratio and reduced neurite growth, in the trisomic condition. The present work presents the correlation between DSCAM gene overexpression and a dysregulation of the PAK pathway, resulting in altered morphological parameters of neuronal plasticity in the trisomic cell

  12. BET Bromodomain Suppression Inhibits VEGF-induced Angiogenesis and Vascular Permeability by Blocking VEGFR2-mediated Activation of PAK1 and eNOS

    PubMed Central

    Huang, Mingcheng; Qiu, Qian; Xiao, Youjun; Zeng, Shan; Zhan, Mingying; Shi, Maohua; Zou, Yaoyao; Ye, Yujin; Liang, Liuqin; Yang, Xiuyan; Xu, Hanshi

    2016-01-01

    The tyrosine kinase receptor vascular endothelial growth factor receptor 2 (VEGFR2) is a critical modulator of angiogenesis. Increasing evidence indicate the important role of bromodomain and extra-terminal domain (BET) of chromatin adaptors in regulating tumor growth and inflammatory response. However, whether BET proteins have a role in angiogenesis and endothelial permeability is unclear. In this study, we observed that treatment with JQ1, a specific BET inhibitor, suppressed in vitro tube formation of human umbilical vein endothelial cells (HUVECs) and in vivo angiogenesis in a Matrigel plug and oxygen-induced retinopathy neovascularization. JQ1 attenuated the VEGF-induced decrease in TEER in HUVECs and prevented Evans blue dye leakage in the VEGF-induced Miles assay in athymic Balb/c nude mice. BET inhibition with JQ1 or shRNA for Brd2 or Brd4 suppressed VEGF-induced migration, proliferation, and stress fiber formation of HUVECs. Furthermore, BET inhibition suppressed phosphorylation of VEGFR2 and PAK1, as well as eNOS activation in VEGF-stimulated HUVECs. Inhibition with VEGFR2 and PAK1 also reduced migration and proliferation, and attenuated the VEGF-induced decrease in TEER. Thus, our observations suggest the important role of BET bromodomain in regulating VEGF-induced angiogenesis. Strategies that target the BET bromodomain may provide a new therapeutic approach for angiogenesis-related diseases. PMID:27044328

  13. Induced production of 1-methoxy-indol-3-ylmethyl glucosinolate by jasmonic acid and methyl jasmonate in sprouts and leaves of pak choi (Brassica rapa ssp. chinensis).

    PubMed

    Wiesner, Melanie; Hanschen, Franziska S; Schreiner, Monika; Glatt, Hansruedi; Zrenner, Rita

    2013-01-01

    Pak choi plants (Brassica rapa ssp. chinensis) were treated with different signaling molecules methyl jasmonate, jasmonic acid, linolenic acid, and methyl salicylate and were analyzed for specific changes in their glucosinolate profile. Glucosinolate levels were quantified using HPLC-DAD-UV, with focus on induction of indole glucosinolates and special emphasis on 1-methoxy-indol-3-ylmethyl glucosinolate. Furthermore, the effects of the different signaling molecules on indole glucosinolate accumulation were analyzed on the level of gene expression using semi-quantitative realtime RT-PCR of selected genes. The treatments with signaling molecules were performed on sprouts and mature leaves to determine ontogenetic differences in glucosinolate accumulation and related gene expression. The highest increase of indole glucosinolate levels, with considerable enhancement of the 1-methoxy-indol-3-ylmethyl glucosinolate content, was achieved with treatments of sprouts and mature leaves with methyl jasmonate and jasmonic acid. This increase was accompanied by increased expression of genes putatively involved in the indole glucosinolate biosynthetic pathway. The high levels of indole glucosinolates enabled the plant to preferentially produce the respective breakdown products after tissue damage. Thus, pak choi plants treated with methyl jasmonate or jasmonic acid, are a valuable tool to analyze the specific protection functions of 1-methoxy-indole-3-carbinole in the plants defense strategy in the future. PMID:23873294

  14. Application of Elephant TB STAT-PAK assay and MAPIA (multi-antigen print immunoassay) for detection of tuberculosis and monitoring of treatment in black rhinoceros (Diceros bicornis).

    PubMed

    Duncan, Ann E; Lyashchenko, Konstantin; Greenwald, Rena; Miller, Michelle; Ball, Ray

    2009-12-01

    Many wildlife species including rhinos are susceptible to infection with Mycobacterium tuberculosis or M. bovis. Antemortem diagnostic testing in large exotic hoof stock species has been limited by challenges associated with test administration, sample collection, and interpretation. Hence, a simple, rapid, blood-based test is needed. Two confirmed M. tuberculosis-infected black rhinoceros and one exposed suspect were evaluated for antibody responses using a lateral-flow rapid test (ElephantTB STAT-PAK) and multi-antigen print immunoassay (MAPIA). All three animals were seropositive by both tests. MAPIA detected antibodies to ESAT-6, CFP10, and MPB83 antigens. When the rhinos were treated with antitubercular therapeutics, their antibody responses gradually declined. One rhinoceros died approximately 9 mo after initiation of treatment and showed an increase in antibody titer shortly before death. The other two rhinoceros, which were treated for 1 and 2 yr, respectively, had no clinical signs or positive culture for M. tuberculosis at the time of necropsy performed 2 or 6 yr later for unrelated reasons. The antibody levels in these rhinos continued to be significantly decreased. The findings suggest that the ElephantTB STAT-PAK and MAPIA may be useful tools to detect M. tuberculosis infection and monitor treatment in black rhinoceros. PMID:20063826

  15. Physical, mechanical and hydration kinetics of particleboards manufactured with woody biomass (Cupressus lusitanica, Gmelina arborea, Tectona grandis), agricultural resources, and Tetra Pak packages.

    PubMed

    Moya, Róger; Camacho, Diego; Oporto, Gloria S; Soto, Roy F; Mata, Julio S

    2014-02-01

    Lignocellulosic wastes resulting from agricultural activities as well as Tetra Pak residues from urban centres can cause significant levels of pollution. A possible action to minimize this problem is to use them in the production of particleboards. The purpose of this study was to evaluate the physical, mechanical, and hydration properties of particleboards manufactured with the mixture of woody biomass (Cupressus lusitanica, Gmelina arborea, and Tectona grandis) and either agricultural wastes [pineapple leaves (Ananas comosus) and palm residues (Elaeis guineensis)] or Tetra Pak residues (TP). The results show that the particleboards prepared with TP and woody biomass can reduce the swelling and water absorption in up to 40% and 50% compared with particleboards without TP. Also, these particleboards had increased flexure resistance and shear stress (up to 100%) compared with those without TP. On the contrary, particleboards prepared with pineapple leaves in combination with woody biomass showed the lowest mechanical properties, particularly for tensile strength, hardness, glue-line shear, and nail and screw evaluation. PMID:24519224

  16. Induced Production of 1-Methoxy-indol-3-ylmethyl Glucosinolate by Jasmonic Acid and Methyl Jasmonate in Sprouts and Leaves of Pak Choi (Brassica rapa ssp. chinensis)

    PubMed Central

    Wiesner, Melanie; Hanschen, Franziska S.; Schreiner, Monika; Glatt, Hansruedi; Zrenner, Rita

    2013-01-01

    Pak choi plants (Brassica rapa ssp. chinensis) were treated with different signaling molecules methyl jasmonate, jasmonic acid, linolenic acid, and methyl salicylate and were analyzed for specific changes in their glucosinolate profile. Glucosinolate levels were quantified using HPLC-DAD-UV, with focus on induction of indole glucosinolates and special emphasis on 1-methoxy-indol-3-ylmethyl glucosinolate. Furthermore, the effects of the different signaling molecules on indole glucosinolate accumulation were analyzed on the level of gene expression using semi-quantitative realtime RT-PCR of selected genes. The treatments with signaling molecules were performed on sprouts and mature leaves to determine ontogenetic differences in glucosinolate accumulation and related gene expression. The highest increase of indole glucosinolate levels, with considerable enhancement of the 1-methoxy-indol-3-ylmethyl glucosinolate content, was achieved with treatments of sprouts and mature leaves with methyl jasmonate and jasmonic acid. This increase was accompanied by increased expression of genes putatively involved in the indole glucosinolate biosynthetic pathway. The high levels of indole glucosinolates enabled the plant to preferentially produce the respective breakdown products after tissue damage. Thus, pak choi plants treated with methyl jasmonate or jasmonic acid, are a valuable tool to analyze the specific protection functions of 1-methoxy-indole-3-carbinole in the plants defense strategy in the future. PMID:23873294

  17. Liposome-mediated delivery of the p21 activated kinase-1 (PAK-1) inhibitor IPA-3 limits prostate tumor growth in vivo.

    PubMed

    Al-Azayzih, Ahmad; Missaoui, Wided N; Cummings, Brian S; Somanath, Payaningal R

    2016-07-01

    P21 activated kinases-1 (PAK-1) is implicated in various diseases. It is inhibited by the small molecule 'inhibitor targeting PAK1 activation-3' (IPA-3), which is highly specific but metabolically unstable. To address this limitation we encapsulated IPA-3 in sterically stabilized liposomes (SSL). SSL-IPA-3 averaged 139nm in diameter, polydispersity index (PDI) of 0.05, and a zeta potential of -28.1, neither of which changed over 14days; however, the PDI increased to 0.139. Analysis of liposomal IPA-3 levels demonstrated good stability, with 70% of IPA-3 remaining after 7days. SSL-IPA-3 inhibited prostate cancer cell growth in vitro with comparable efficacy to free IPA-3. Excitingly, only a 2day/week dose of SSL-IPA-3 was needed to inhibit the growth of prostate xenografts in vivo, while a similar dose of free IPA-3 was ineffective. These data demonstrate the development and clinical utility of a novel liposomal formulation for the treatment of prostate cancer. PMID:26949163

  18. Impact of fermentation on phenolic compounds in leaves of pak choi (Brassica campestris L. ssp. chinensis var. communis) and Chinese leaf mustard (Brassica juncea coss).

    PubMed

    Harbaum, Britta; Hubbermann, Eva Maria; Zhu, Zhujun; Schwarz, Karin

    2008-01-01

    Four different cultivars of Chinese Brassica vegetables (two pak choi cultivars and two Chinese leaf mustard cultivars) were fermented according to a traditional Chinese method called pickling. The plant material was investigated before and after the fermentation procedure to determine the qualitative and quantitative changes in its polyphenols. A detailed description of the identified phenolic compounds of leaf mustard by HPLC-ESI-MS(n) is presented here for the first time, including hydroxycinnamic acid mono- and diglycosides (gentiobioses) and flavonoid tetraglycosides. Flavonoid derivatives with a lower molecular mass (di- and triglycosides) and aglycones of flavonoids and hydroxycinnamic acids were detected in fermented cabbages compared to the main compounds detected in nonfermented cabbages (tri- and tetraglycosides of flavonoids and hydroxycinnamic acid derivatives of malic acid, glycoside, and quinic acid). During the fermentation process, contents of flavonoid derivatives and some hydroxycinnamic acid derivatives were found to decrease. Some marginal losses of polyphenols were observed even in the kneading step of the plant material prior to the fermentation procedure. The antioxidative potential of fermented cabbages was much higher compared to that of nonfermented cabbages in the TEAC assay, but not observable in the DPPH assay. The increase of the antioxidative potential detected in the TEAC assay was attributed to the qualitative changes of polyphenols as well as other reductones potentially present. PMID:18078315

  19. Update of the tectonic model for the Pannonian basin: a contribution to the seismic hazard reassessment of the Paks NPP (Hungary)

    NASA Astrophysics Data System (ADS)

    Horváth, Ferenc; Tóth, Tamás; Wórum, Géza; Koroknai, Balázs; Kádi, Zoltán; Kovács, Gábor; Balázs, Attila; Visnovitz, Ferenc

    2015-04-01

    The planned construction of two new units at the site of the Paks NPP requires a comprehensive site investigation including complete reassessment of the seismic hazard according to the Hungarian as well as international standards. Following the regulations of the Specific Safety Guide no. 9 (IAEA 2010), the approved Hungarian Geological Investigation Program (HGIP) includes integrated geological-geophysical studies at different scales. The regional study aims at to elaborate a new synthesis of all published data for the whole Pannonian basin. This task is nearly completed and the main outcomes have already been published (Horváth et al. 2015). The near regional study is in progress and addresses the construction of a new tectonic model for the circular area with 50 km radius around the NPP using a wealth of unpublished oil company seismic and borehole data. The site vicinity study has also been started with a core activity of 300 km² 3D seismic data acquisition, processing and interpretation assisted by a series of additional geophysical surveys, new drillings and geological mapping. This lecture will present a few important results of the near regional study, which sheds new light on the intricate tectonic evolution of the Mid-Hungarian Fault Zone (MHFZ), which is a strongly deformed belt between the Alcapa and Tisza-Dacia megatectonic units. The nuclear power plant is located at the margin of the Tisza unit near to the southern edge of the MHFZ. Reassessment of seismic hazard at the site of the NPP requires better understanding of the Miocene to Recent tectonic evolution of this region in the central part of the Pannonian basin. Early to Middle Miocene was a period of rifting with formation of 1 to 3 km deep half-grabens filled with terrestrial to marine deposits and large amount of rift-related volcanic material. Graben fill became strongly deformed as a consequence of juxtaposition of the two megatectonic units leading to strong compression and development of

  20. Documentation and Control of Flow Separation on a Low Pressure Turbine Linear Cascade of Pak-B Blades Using Plasma Actuators

    NASA Technical Reports Server (NTRS)

    Corke, Thomas c.; Thomas, FLint, O.; Huang, Junhui

    2007-01-01

    This work involved the documentation and control of flow separation that occurs over low pressure turbine (LPT) blades at low Reynolds numbers. A specially constructed linear cascade was utilized to study the flow field over a generic LPT cascade consisting of Pratt & Whitney "Pak-B" shaped blades. Flow visualization, surface pressure measurements, LDV measurements, and hot-wire anemometry were conducted to examine the flow fields with and without separation control. Experimental conditions were chosen to give a range of chord Reynolds numbers (based on axial chord and inlet velocity) from 10,000 to 100,000, and a range of freestream turbulence intensities from u'/U(infinity) = 0.08 to 2.85 percent. The blade pressure distributions were measured and used to identify the region of separation that depends on Reynolds number and the turbulence intensity. Separation control was performed using dielectric barrier discharge (DBD) plasma actuators. Both steady and unsteady actuation were implemented and found to work well. The comparison between the steady and unsteady actuators showed that the unsteady actuators worked better than the steady ones. For the steady actuators, it was found that the separated region is significantly reduced. For the unsteady actuators, where the signal was pulsed, the separation was eliminated. The total pressure losses (a low Reynolds number) was reduced by approximately a factor of two. It was also found that lowest plasma duty cycle (10 percent in this work) was as effective as the highest plasma duty cycle (50 percent in this work). The mechanisms of the steady and unsteady plasma actuators were studied. It was suggested by the experimental results that the mechanism for the steady actuators is turbulence tripping, while the mechanism for the unsteady actuators is to generate a train of spanwise structures that promote mixing.

  1. Structural and Kinetic Effects of PAK3 phosphorylation mimic of cTnI(S151E) on the cTnC-cTnI Interaction in the Cardiac Thin Filament

    PubMed Central

    Ouyang, Yexin; Mamidi, Ranganath; Jayasundar, Jayant James; Chandra, Murali; Dong, Wen-Ji

    2010-01-01

    Residue Ser151 of cTnI is known to be phosphorylated by p21-activated kinase 3 (PAK3). It has been found that PAK3-mediated phosphorylation of cTnI induces an increase in myofilament Ca2+ sensitivity, but the detailed mechanism is unknown. We investigated how the structural and kinetic effects mediated by pseudo-phosphorylation of cTnI (S151E) modulates Ca2+-induced activation of cardiac thin filaments. Using steady-state, time-resolved Förster Resonance Energy Transfer (FRET) and stopped-flow kinetic measurements, we monitored Ca2+-induced changes in cTnI-cTnC interactions. Measurements were done using reconstituted thin filaments, which contained the pseudo-phosphorylated cTnI(S151E). We hypothesized that the thin filament regulation is modulated by altered cTnC-cTnI interactions due to charge modification caused by the phosphorylation of Ser151 in cTnI. Our results showed that the pseudo-phosphorylation of cTnI (S151E) sensitizes structural changes to Ca2+ by shortening the intersite distances between cTnC and cTnI. Furthermore, kinetic rates of Ca2+ dissociation-induced structural change in the regulatory region of cTnI were significantly reduced by cTnI (S151E). The aforementioned effects of pseudo-phosphorylation of cTnI were similar to the effects of strong crossbridges on structural changes in cTnI. Our results provide novel information on how cardiac thin filament regulation is modulated by PAK3 phosphorylation of cTnI. PMID:20540949

  2. Neuronal filopodium formation induced by the membrane glycoprotein M6a (Gpm6a) is facilitated by coronin-1a, Rac1, and p21-activated kinase 1 (Pak1).

    PubMed

    Alvarez Juliá, Anabel; Frasch, Alberto C; Fuchsova, Beata

    2016-04-01

    Stress-responsive neuronal membrane glycoprotein M6a (Gpm6a) functions in neurite extension, filopodium and spine formation and synaptogenesis. The mechanisms of Gpm6a action in these processes are incompletely understood. Previously, we identified the actin regulator coronin-1a (Coro1a) as a putative Gpm6a interacting partner. Here, we used co-immunoprecipitation assays with the anti-Coro1a antibody to show that Coro1a associates with Gpm6a in rat hippocampal neurons. By immunofluorescence microscopy, we demonstrated that in hippocampal neurons Coro1a localizes in F-actin-enriched regions and some of Coro1a spots co-localize with Gpm6a labeling. Notably, the over-expression of a dominant-negative form of Coro1a as well as its down-regulation by siRNA interfered with Gpm6a-induced filopodium formation. Coro1a is known to regulate the plasma membrane translocation and activation of small GTPase Rac1. We show that Coro1a co-immunoprecipitates with Rac1 together with Gpm6a. Pharmacological inhibition of Rac1 resulted in a significant decrease in filopodium formation by Gpm6a. The same was observed upon the co-expression of Gpm6a with the inactive GDP-bound form of Rac1. In this case, the elevated membrane recruitment of GDP-bound Rac1 was detected as well. Moreover, the kinase activity of the p21-activated kinase 1 (Pak1), a main downstream effector of Rac1 that acts downstream of Coro1a, was required for Gpm6a-induced filopodium formation. Taken together, our results provide evidence that a signaling pathway including Coro1a, Rac1, and Pak1 facilitates Gpm6a-induced filopodium formation. Formation of filopodia by membrane glycoprotein M6a (Gpm6a) requires actin regulator coronin-1a (Coro1a), known to regulate plasma membrane localization and activation of Rac1 and its downstream effector Pak1. Coro1a associates with Gpm6a. Blockage of Coro1a, Rac1, or Pak1 interferes with Gpm6a-induced filopodium formation. Moreover, Gpm6a facilitates Rac1 membrane recruitment

  3. Your Nose Knows. [Project ECOLogy ELE Pak, Meaney Pak].

    ERIC Educational Resources Information Center

    Meaney, Marie

    This is one of a series of units for environmental education developed by the Highline Public Schools. This unit is designed for kindergarten pupils, but could be used effectively with primary pupils. The six lessons use the sense of smell to investigate various aspects of the earth, seasons, animals, and commercial use of fragrances. Each lesson…

  4. From Rocks to Pots. [Project ECOLogy ELE Pak, Grim Pak].

    ERIC Educational Resources Information Center

    Grim, Dale

    This is one of a series of units for environmental education developed by the Highline Public Schools. The unit is designed for use by art classes at the secondary school level; it illustrates the availability of natural clay and provides the student with experiences such as digging the clay, locating desirable clays, preparing it for production,…

  5. [Peabody's Time Machine. Project ECOLogy ELE Pak, Hirschel Pak].

    ERIC Educational Resources Information Center

    Hirschel, John

    This is one of a series of units for environmental education developed by the Highline Public Schools. This unit is designed for use by a substitute teacher for instruction of intermediate grade elementary school pupils. The kit provides three days of lesson plans. There is closure at the end of each lesson and each day. Much emphasis is placed on…

  6. Archaeology/Ecology. [Project ECOLogy ELE Pak, Muccilli Pak].

    ERIC Educational Resources Information Center

    Muccilli, Kathie

    This is one of a series of units for environmental education developed by the Highline Public Schools. This unit was written for seventh-grade students in anthropology. The six lessons and suggested activities will take from 15 to 30 days to complete. Each lesson includes the concept of the lesson, materials needed, notes to the teacher,…

  7. Water. [Project ECOLogy ELE Pak, McGrath Pak].

    ERIC Educational Resources Information Center

    McGrath, Jo Ellen

    This is one of a series of units for environmental education developed by the Highline Public Schools. This unit on water is designed for primary grades. Included are ten lessons. Each lesson includes the concepts of the lesson, materials needed, time for the activity, procedure, evaluative activities, and follow-up activities. Included are…

  8. Earth Art. [Project ECOLogy ELE Pak, Dye Pak].

    ERIC Educational Resources Information Center

    Dye, Dick

    This is one of a series of units for environmental education developed by the Highline Public Schools. This unit for elementary school children is designed to help bring more art into the classroom and to help students become more aware of their environment. Included are six lessons and a bibliography of suggested student references. Each lesson…

  9. Thoughts from You. [Project ECOLogy ELE Pak, Northrop Pak].

    ERIC Educational Resources Information Center

    Northrop, Liz

    This is one of a series of units for environmental education developed by the Highline Public Schools. This unit is designed to assist sixth-grade students to increase their awareness and appreciation of their environment, and to develop their thinking and feelings concerning it by using creative writing. It is recommended that the seven lessons…

  10. The Games Cities Play. [Project ECOLogy ELE Pak, Amoe Pak].

    ERIC Educational Resources Information Center

    Amoe, Ruth

    This is a simulation game and a part of the environmental education program developed by the Highline Public Schools. The game emphasizes why a city is formed, how it grows, where it develops, and some problems with which it must cope. It is designed to be used with elementary students in the intermediate grades. The materials were tried and…

  11. Home Sweet Earth. [Project ECOLogy ELE Pak, Meaney Pak].

    ERIC Educational Resources Information Center

    Meaney, Marie

    This is one of a series of units for environmental education developed by the Highline Public Schools. The emphasis of the 10 lessons in this unit is on energy, the earth's resources, and the use of earth resources, by man and other living things. The materials are designed for use at grade 1, but could be used in higher grades. Each lesson…

  12. Acting for Ecology. [Project ECOLogy ELE Pak, Ausen Pak].

    ERIC Educational Resources Information Center

    Ausen, Wayne

    This is one of a series of units for environmental education developed by the Highline Public Schools. This unit was designed for the fourth-, fifth-, and sixth-grades to learn about ecology with the use of creative drama. The six lessons can be interchanged in any way that fits the needs of the class. Use of all six lessons should take about two…

  13. Water. [Project ECOLogy ELE Pak, Toulouse & Edgar Pak].

    ERIC Educational Resources Information Center

    Toulouse, Dick; Edgar, Linda

    This is one of a series of units for environmental education developed by the Highline Public Schools. This unit on water is designed for seventh-grade science classes. Included are 13 lessons. Each lesson usually includes the concept of the lesson, materials needed, notes to the teacher, procedure, and evaluation activities. In addition, there…

  14. Biotic Communities. [Project ECOLogy ELE Pak, Amoe-Thorson Pak].

    ERIC Educational Resources Information Center

    Amoe, Ruth; Thorson, Michael

    This is one of a series of units for environmental education developed by the Highline Public Schools. This unit provides a number of activities to introduce students to ways of studying biotic communities, help them become good observers, and provide them with opportunities to use their skills. The materials include suggested activities, and…

  15. Your World My World. [Project ECOLogy ELE Pak, Peace Pak].

    ERIC Educational Resources Information Center

    Peace, Shirley

    This is one of a series of units for environmental education developed by the Highline Public Schools. This unit for kindergarten introduces the pupil to the concept of environment. Various aspects of the environment are explored through 14 lessons using our five senses. Each activity includes the concept of the lesson, materials needed,…

  16. Anthropology - Ecology. [Project ECOLogy ELE Pak, Skidmore Pak].

    ERIC Educational Resources Information Center

    Skidmore, Margaret

    This is one of a series of units for environmental education developed by the Highline Public Schools. The unit may be used as an introduction to the study of anthropology, the influence of ecology on the study of anthropology, and an introduction to the physical school environment. For best results, it should be used at the beginning of the…

  17. Exponential Explosions! Today.... Tomorrow.... ? [Project ECOLogy ELE Pak, Jensen Pak].

    ERIC Educational Resources Information Center

    Jensen, Melanie

    This is one of a series of units for environmental education developed by the Highline Public Schools. The unit is designed for junior high school mathematics classes and emphasizes applications of exponents to problems of population growth and pollution. The nine lessons are designed for about eleven school days. Each lesson includes the concept…

  18. Energy Futures... [Project ECOLogy ELE Pak, Parr Pak].

    ERIC Educational Resources Information Center

    Parr, Donald

    This is one of a series of units for environmental education developed by the Highline Public Schools. This unit on energy is designed for junior high school science students. The 11 concepts of the unit have been developed into 11 lessons that should take from two to three weeks to complete. Each lesson includes the concept of the lesson,…

  19. Natural or Organic Foods? [Project ECOLogy ELE Pak, Schmidt Pak].

    ERIC Educational Resources Information Center

    Schmidt, Linda

    This is one of a series of units for environmental education developed by the Highline Public Schools. The unit is designed for secondary students in home economics classes. The content of the units focuses on natural and organic foods, characteristics of the foods, and uses of the foods. The seven lessons in this unit are designed to last over a…

  20. The Drip Impact. [Project ECOLogy ELE Pak, Jack Pak].

    ERIC Educational Resources Information Center

    Staudacher, Jack

    This is one of a series of units for environmental education developed by the Highline Public Schools. The unit is designed for senior high science classes. The primary emphasis of the material is on water, water analysis, and possible methods of watershed management; while the materials were designed for use in and around the Highline Public…

  1. And Then - Recycling. [Project ECOLogy ELE Pak, Lewis Pak].

    ERIC Educational Resources Information Center

    Lewis, Dave

    This is one of a series of units for environmental education developed by the Highline Public Schools. There are seven concepts in this unit on recycling which is designed for grade five and six students. Each concept has one lesson that is comprised of several activities. Several suggested extra activities have been added to further the students'…

  2. River sinuosity changes as indicators of the possible neotectonic activity - a case study on the Danube River between Paks (Hungary) and Beograd (Serbia)

    NASA Astrophysics Data System (ADS)

    Petrovszki, Judit

    2010-05-01

    The meandering, pre-regulation river planforms of the Danube River, between Paks (Hungary) and Beograd (Serbia) was digitized from the map sheets of the Second Military Survey of the Habsburg Empire (Timár et al., 2006). These maps were surveyed before or simultaneously with the river control works, so it is possible to follow the natural riverbeds, the natural changing of the meandering structure. The sinuosity values were calculated with different window sizes, and displayed in a spectrum-like diagram (sinuosity spectra; after van Balen et al., 2008). The channel sinuosity of this river is analyzed in order to draw conclusions on the neotectonic activity of the western part of the Great Hungarian Plain. Several points of sinuosity change were identified. To prove that these are of neotectonic origin, a neotectonic map and seismic sections crossing the study area, were also analyzed. Significant sinuosity changes (low to high or high to low), spatially correlated to linear features identified in seismic survey sections or in tectonic maps (Horváth et al., 2006), indicate their neotectonic activity (Ouchi, 1985; Timár, 2003; Zámolyi et al., 2010). Upstream of the Hungarian-Serbian border, the Duna (Danube) has anabranching planform, the Baracskai-Duna is the main anabranch. There is a fault on the neotectonic map, crossing both rivers, and cause the decreasing of the sinuosity. The vertical activity of the structural line, which is more or less parallel to the international border, is verified by the sinuosity change. The direction of the change (from high to low sinuosity values) correlates with the normal fault character, shown on the map. Another significant sinuosity change occurs downstream of the Drava River confluence. The explanation of this change can be of two kinds. First, there is a known tectonic feature along the Drava River, with dextral faulting. The sinuosity increase could indicate a small active vertical component of this structural line

  3. Prolactin-Stimulated Activation of ERK1/2 Mitogen-Activated Protein Kinases is Controlled by PI3-Kinase/Rac/PAK Signaling Pathway in Breast Cancer Cells

    PubMed Central

    Aksamitiene, Edita; Achanta, Sirisha; Kolch, Walter; Kholodenko, Boris N.; Hoek, Jan B.; Kiyatkin, Anatoly

    2011-01-01

    There is strong evidence that deregulation of prolactin (PRL) signaling contributes to pathogenesis and chemoresistance of breast cancer. Therefore, understanding cross-talk between distinct signal transduction pathways triggered by activation of the prolactin receptor (PRL-R), is essential for elucidating the pathogenesis of metastatic breast cancer. In this study, we applied a sequential inhibitory analysis of various signaling intermediates to examine the hierarchy of protein interactions within the PRL signaling network and to evaluate the relative contributions of multiple signaling branches downstream of PRL-R to the activation of the extracellular signal-regulated kinases ERK1 and ERK2 in T47D and MCF-7 human breast cancer cells. Quantitative measurements of the phosphorylation/activation patterns of proteins showed that PRL simultaneously activated Src family kinases (SFKs) and the JAK/STAT, phosphoinositide-3 (PI3)-kinase/Akt and MAPK signaling pathways. The specific blockade or siRNA-mediated suppression of SFK/FAK, JAK2/STAT5, PI3-kinase/PDK1/Akt, Rac/PAK or Ras regulatory circuits revealed that (1) the PI3-kinase/Akt pathway is required for activation of the MAPK/ERK signaling cascade upon PRL stimulation; (2) PI3-kinase-mediated activation of the c-Raf-MEK1/2-ERK1/2 cascade occurs independent of signaling dowstream of STATs, Akt and PKC, but requires JAK2, SFKs and FAK activities; (3) activated PRL-R mainly utilizes the PI3-kinase-dependent Rac/PAK pathway rather than the canonical Shc/Grb2/SOS/Ras route to initiate and sustain ERK1/2 signaling. By interconnecting diverse signaling pathways PLR may enhance proliferation, survival, migration and invasiveness of breast cancer cells. PMID:21726627

  4. Prolactin-stimulated activation of ERK1/2 mitogen-activated protein kinases is controlled by PI3-kinase/Rac/PAK signaling pathway in breast cancer cells.

    PubMed

    Aksamitiene, Edita; Achanta, Sirisha; Kolch, Walter; Kholodenko, Boris N; Hoek, Jan B; Kiyatkin, Anatoly

    2011-11-01

    There is strong evidence that deregulation of prolactin (PRL) signaling contributes to pathogenesis and chemoresistance of breast cancer. Therefore, understanding cross-talk between distinct signal transduction pathways triggered by activation of the prolactin receptor (PRL-R), is essential for elucidating the pathogenesis of metastatic breast cancer. In this study, we applied a sequential inhibitory analysis of various signaling intermediates to examine the hierarchy of protein interactions within the PRL signaling network and to evaluate the relative contributions of multiple signaling branches downstream of PRL-R to the activation of the extracellular signal-regulated kinases ERK1 and ERK2 in T47D and MCF-7 human breast cancer cells. Quantitative measurements of the phosphorylation/activation patterns of proteins showed that PRL simultaneously activated Src family kinases (SFKs) and the JAK/STAT, phosphoinositide-3 (PI3)-kinase/Akt and MAPK signaling pathways. The specific blockade or siRNA-mediated suppression of SFK/FAK, JAK2/STAT5, PI3-kinase/PDK1/Akt, Rac/PAK or Ras regulatory circuits revealed that (1) the PI3-kinase/Akt pathway is required for activation of the MAPK/ERK signaling cascade upon PRL stimulation; (2) PI3-kinase-mediated activation of the c-Raf-MEK1/2-ERK1/2 cascade occurs independent of signaling dowstream of STATs, Akt and PKC, but requires JAK2, SFKs and FAK activities; (3) activated PRL-R mainly utilizes the PI3-kinase-dependent Rac/PAK pathway rather than the canonical Shc/Grb2/SOS/Ras route to initiate and sustain ERK1/2 signaling. By interconnecting diverse signaling pathways PLR may enhance proliferation, survival, migration and invasiveness of breast cancer cells. PMID:21726627

  5. Targeting Cdc42 with the small molecule drug AZA197 suppresses primary colon cancer growth and prolongs survival in a preclinical mouse xenograft model by downregulation of PAK1 activity

    PubMed Central

    2013-01-01

    Background Rho GTPases play important roles in cytoskeleton organization, cell cycle progression and are key regulators of tumor progression. Strategies to modulate increased Rho GTPase activities during cancer progression could have therapeutic potential. Methods We report here the characterization of a Cdc42-selective small-molecule inhibitor AZA197 for the treatment of colon cancer that was developed based on structural information known from previously developed compounds affecting Rho GTPase activation. We investigated the effects of AZA197 treatment on RhoA, Rac1 and Cdc42 activities and associated molecular mechanisms in colon cancer cells in vitro. Therapeutic effects of AZA197 were examined in vivo using a xenograft mouse model of SW620 human colon cancer cells. After treatment, tumors were excised and processed for Ki-67 staining, TUNEL assays and Western blotting to evaluate proliferative and apoptotic effects induced by AZA197. Results In SW620 and HT-29 human colon cancer cells, AZA197 demonstrated selectivity for Cdc42 without inhibition of Rac1 or RhoA GTPases from the same family. AZA197 suppressed colon cancer cell proliferation, cell migration and invasion and increased apoptosis associated with down-regulation of the PAK1 and ERK signaling pathways in vitro. Furthermore, systemic AZA197 treatment reduced tumor growth in vivo and significantly increased mouse survival in SW620 tumor xenografts. Ki-67 staining and tissue TUNEL assays showed that both inhibition of cell proliferation and induction of apoptosis associated with reduced PAK/ERK activation contributed to the AZA197-induced therapeutic effects in vivo. Conclusions These data indicate the therapeutic potential of the small-molecule inhibitor AZA197 based on targeting Cdc42 GTPase activity to modulate colorectal cancer growth. PMID:24279335

  6. Zip Pak for Second Reader Level.

    ERIC Educational Resources Information Center

    Scott, Norval C., Comp.

    The student's workbook was developed to give additional aid in reading and vocabulary building to migrant children between the ages of 8 and 12 years old, working at a second grade reading level. Six lessons are given in this student's workbook. Each lesson consists of: words to learn, a story to read, questions to answer, a picture to draw, a…

  7. Exploration with Garbage. [Project ECOLogy ELE Pak, Lund and Wolff Pak].

    ERIC Educational Resources Information Center

    Lund, Cherie; Wolff, Chanelle

    This is one of a series of units for environmental education developed by the Highline Public Schools. This unit is concerned with the topic of garbage. The eleven lessons explore what garbage is, problems of littering, ways to reduce garbage, and ways to use garbage. The materials were designed to be used with kindergarten pupils, but could be…

  8. ...About This Problem of Air Pollution... . [Project ECOLogy ELE Pak, Wright Pak].

    ERIC Educational Resources Information Center

    Wright, Jan

    This is one of a series of units for environmental education developed by the Highline Public Schools. The lessons in this unit are designed to help students discover causes, effects, and results of air pollution through involvement in various activities; it is recommended for intermediate grade elementary school pupils. The unit can be used…

  9. Mind-Full of Ecology. [Project ECOLogy ELE Pak, Horton Pak].

    ERIC Educational Resources Information Center

    Horton, Sue

    This is one of a series of units for environmental education developed by the Highline Public Schools. This ecology unit has been designed to be used as an individualized reading program, the duration of which is about three weeks. The purpose is to help intermediate grade elementary school pupils become more aware of their natural world and their…

  10. The Sky Is Falling: A Study Of Particulates... . [Project ECOLogy ELE Pak, Thompson Pak].

    ERIC Educational Resources Information Center

    Thompson, Dennis W.

    This is one of a series of units for environmental education developed by the Highline Public Schools. Designed for secondary school science classes, the unit is concerned with particulate matter of air pollution. Five lessons are included. The lessons include construction of equipment and collecting data. (RH)

  11. Ecological Smorgasbord: A Balanced Reading Diet. [Project ECOLogy ELE Pak, Lorain & Backman Pak].

    ERIC Educational Resources Information Center

    Lorain, Sue; Backman, Judi

    This is one of a series of units for environmental education developed by the Highline Public Schools. This material was basically designed to be used as an individualized reading kit for the intermediate grade student. The books in this kit readily lend themselves to a supplementary reading program as part of a science unit. Depending on a…

  12. Overpopulation Produces.... What Are We Going To Do About It? [Project ECOLogy ELE Pak, Edgar Pak

    ERIC Educational Resources Information Center

    Edgar, Linda

    This unit is one of a series produced for environmental education programs by the Highline Public Schools. These materials are designed for use with junior high school students studying the concept of population, population trends, and problems created by changes in populations. The seven concepts in the unit take about three weeks to complete.…

  13. Living Today with an Eye Toward Tomorrow. [Project ECOLogy ELE Pak, Wilder Pak].

    ERIC Educational Resources Information Center

    Wilder, Lou

    This is one of a series of units for environmental education developed by the Highline Public Schools. This unit is designed for a ninth-grade Home Economics class. Included are five lessons. Most activities relate to energy use. Each lesson includes the concept of the lesson, materials needed, notes to the teacher, and procedure. (RH)

  14. This Land Is Your Land. [Project ECOLogy ELE Pak, Weber Pak].

    ERIC Educational Resources Information Center

    Weber, Lee

    This is one of a series of units for environmental education developed by the Highline Public Schools. The unit has been constructed for use by intermediate grade elementary school pupils. The seven lessons are designed to inform students about the land to develop a land ethic. The unit should be able to be completed in two to three weeks. The…

  15. It's All in the Air. [Project ECOLogy ELE Pak, Wright Pak].

    ERIC Educational Resources Information Center

    Wright, Jan

    This is one of a series of units for environmental education developed by the Highline Public Schools. The unit is designed for intermediate grade elementary school students. Emphasized in the units are air, the use of air, and air pollution. The seven lessons can be used consecutively or spaced throughout the year. Each lesson includes the…

  16. Air Pollution: What You Can & Can't See. [Project ECOLogy ELE Pak, Thompson Pak.].

    ERIC Educational Resources Information Center

    Thompson, Dennis W.

    This is one of a series of units for environmental education developed by the Highline Public Schools. The unit on air pollution is designed for secondary school students in grades 7 through 12. There are five lessons in the unit; since some of the activities can take as long as 90 days, use of the materials needs to be carefully planned. Each…

  17. Round and Round It Goes: A Study of Ecological Cycles. [Project ECOLogy ELE Pak, Roaa Pak].

    ERIC Educational Resources Information Center

    Ross, Catherine

    This is one of a series of units for environmental education developed by the Highline Public Schools. This unit, designed for third- and fourth-grade students, emphasizes cycles and focuses on the water, oxygen, and nutrient cycles. The eleven lessons in this unit are designed to take one-half to one hour each. Use of the extra activities would…

  18. Practice What You Preach! [Project ECOLogy ELE Pak, Backman & Lorain Pak].

    ERIC Educational Resources Information Center

    Backman, Judi; Lorain, Sue

    This is one of a series of units for environmental education developed by the Highline Public Schools. The unit is designed to be used with intermediate grade elementary school pupils. The intent of the 10 lessons is to provide activities that create a positive inner environment for each child so that effectiveness in the immediate and global…

  19. You Are What You Eat. [Project ECOLogy ELE Pak, Campbell Pak].

    ERIC Educational Resources Information Center

    Campbell, Marsha

    This is one of a series of units for environmental education developed by the Highline Public Schools. The unit for elementary students in intermediate grades is concerned with nutrition, basic food groups, food production careers, future trends in food production and population growth, and ecology. The unit of 18 lessons is to be used over a six…

  20. Conducting Environmental Assessment Of Your Local Community. [Project ECOLogy ELE Pak, Files Pak].

    ERIC Educational Resources Information Center

    Files, Tom

    This is one of a series of units for environmental education developed by the Highline Public Schools. The unit is designed for use by junior high school social studies students. Emphasis of the unit is on planning and conducting an environmental assessment of your local community. The unit contains ten lessons as well as supplementary printed…

  1. Eco-Kids: Experiment with Air on Spaceship Earth. [Project ECOLogy ELE Pak, Bell Pak].

    ERIC Educational Resources Information Center

    Bell, Loretta

    This is one of a series of units for environmental education developed by the Highline Public Schools. The unit, designed for intermediate grades in the elementary schools, is concerned with the study of air, air pollution, effects of air pollution, and ways of improving the quality of the air. Six lessons are included in the unit; most of the…

  2. Who Has a Better Idea? [Project ECOLogy ELE Pak, Hearst Pak].

    ERIC Educational Resources Information Center

    Hearst, Gordon

    This is one of a series of units for environmental education developed by the Highline Public Schools. This unit on technology, the environment, natural resources, and human values, is designed for upper grade elementary school pupils. Each of the 10 lessons is designed for a 1-2 hour period of time. Each lesson includes the concept of the lesson,…

  3. Eco-Kids Fly Off to the Forests. [Project ECOLogy ELE Pak, Bell Pak].

    ERIC Educational Resources Information Center

    Bell, Loretta

    This is one of a series of units for environmental education developed by the Highline Public Schools. This unit was designed for use with fourth-grade students; it focuses on three forest biomes. Each of the biomes has characteristics of its own. The unit includes eight lessons, as well as additional activities. The unit, which incorporates…

  4. Food: The Challenge to Manage. [Project ECOLogy ELE Pak, Roush Pak].

    ERIC Educational Resources Information Center

    Roush, Judy

    This is one of a series of units for environmental education developed by the Highline Public Schools. The unit is designed for students at the senior high level who have a basic knowledge of nutrition, some experience in menu planning, and who are ready to put this knowledge of nutrition to work in selecting foods to attain maximum nutrition with…

  5. Pak-India collaborations in health: insights and way forward.

    PubMed

    Nishtar, Sania; Chishtie, Farrukh; Chishtie, Jawad; Malik, Mariam; Ehsan, Haamna; Qazi, Yasmeen; Amjad, Saba

    2015-01-01

    Commonalities abound varied health challenges confronting Pakistan and India. Some of these warrant joint collaborative solutions. This study presents existing health collaborations by mapping out active connections between the countries, through a literature review and clinical and public health professionals' interviews. It reveals that a diversity of practices exist beyond the usual notions of 'collaboration' usually depicted in the literature. Outcomes from such initiatives included enhanced learning and exchanges of information and research across various communities and contexts. In various adoptions of the term, contextualisation within and between countries and amongst particular communities is cited as important. Travel and mobility restriction emerged as one key issue that hampers and discourages collaborations. Key lessons conveyed by the participants included an enabling environment, missing on both sides of the border. Opportunities and recommendations are presented to address the obstacles that discourage cross-border dialogue and to enhance collaborations between the two countries. PMID:26189874

  6. OPTIMIZING THE PAKS METHOD FOR MEASURING AIRBORNE ACROLEIN

    EPA Science Inventory

    Airborne acrolein is produced from the combustion of fuel and tobacco and is of concern due to its potential for respiratory tract irritation and other adverse health effects. DNPH active-sampling is a method widely used for sampling airborne aldehydes and ketones (carbonyls); ...

  7. Cities Then and Now, and Where Do We Go from Here? [Project ECOLogy ELE Pak, Skidmore, Muccilli Pak].

    ERIC Educational Resources Information Center

    Skidmore, Margaret; Muccilli, Kathie

    This is one of a series of units for environmental education developed by the Highline Public Schools. This unit on cities and urban life is designed for use with ninth-grade students, but could be used with other students. A variety of activities and materials for the activities are included. While some of the activities apply directly to…

  8. Please Touch ... Touching Is Living - And Living Is O.K.! [Project ECOLogy ELE Pak, Thorsen-Amoe Pak].

    ERIC Educational Resources Information Center

    Thorson, Michael; Amoe, Ruth

    This is one of a series of units for environmental education developed by the Highline Public Schools. This unit is designed to direct intermediate grade pupils to positive attitudes and actions in the preservation of their environment. The culminating activity is the construction and placement of positive ecology signs. The goals of this unit are…

  9. Ever Stop to Think Man's Survival Is Dependent on His Use of Food Resources? [Project ECOLogy ELE Pak, Nelson Pak].

    ERIC Educational Resources Information Center

    Nelson, Judy

    This is one of a series of units for environmental education developed by the Highline Public Schools. This unit is designed for senior high school students who have a basic knowledge of nutrition and some experience in menu planning. The five lessons provide experiences in selecting, preparing, and storing foods to attain maximum nutrition with a…

  10. PAKS: Parents-and-Kids Science. 24 Activities for Kids and Adults To Share.

    ERIC Educational Resources Information Center

    McKenzie, Danny L.

    This activity book designed for grades 1-3 provides teachers with ready-to-use materials designed to get parents and children excited about science, help establish a home-school connection, and provide interesting learning activities for children to share with adults. This program gets parents involved in developing their children's science…

  11. Pattern of fall injuries in Pakistan: the Pakistan National Emergency Department Surveillance (Pak-NEDS) study

    PubMed Central

    2015-01-01

    Background We aimed to analyse the frequency and patterns of fall-related injuries presenting to the emergency departments (EDs) across Pakistan. Methods Pakistan National Emergency Departments surveillance system collected data from November 2010 to March 2011 on a 24/7 basis using a standardized tool in seven major EDs (five public and two private hospitals) in six major cities of Pakistan. For all patients presenting with fall-related injuries, we analysed data by intent with focus on unintentional falls. Simple frequencies were run for basic patient demographics, mechanism of falls, outcomes of fall injuries, mode of arrival to ED, investigations, and procedures with outcomes. Results There were 3335 fall-related injuries. In cases where intent was available, two-thirds (n = 1186, 65.3%) of fall injuries were unintentional. Among unintentional fall patients presenting to EDs, the majority (76.9%) were males and between 15-44 years of age (69%). The majority of the unintentional falls (n = 671, 56.6%) were due to slipping, followed by fall from height (n = 338, 28.5%). About two-thirds (n = 675, 66.6%) of fall injuries involved extremities, followed by head/neck (n = 257, 25.4%) and face (n = 99, 9.8%). Most of the patients were discharged from the hospital (n = 1059, 89.3%). There were 17 (1.3%) deaths among unintentional fall cases. Conclusion Falls are an important cause of injury-related visits to EDs in Pakistan. Most of the fall injury patients were men and in a productive age group. Fall injuries pose a burden on the healthcare system, especially emergency services, and future studies should therefore focus on safety measures at home and in workplaces to reduce this burden. PMID:26691821

  12. Satellite based classification (haze, fog) and affected area estimation over Indo - Pak Sub-Continent

    NASA Astrophysics Data System (ADS)

    Ghauri, Badar; Zafar, Sumaira

    2016-07-01

    Northern Pakistan and bordering Indian Punjab experience intense smog and fog during fall and winters. Environmentalists have been raising their voices over the situation and demanded control over regional emissions to save the livelihood of millions of dwellers whose trade, commerce and agriculture is at stake because of long smog/ fog spells.. This paper estimates the area affected by haze, smog and fog during 2006- 2010. MODIS (geo-referenced MODIS subsets India1, 2 &3) of the area in Pakistan and India from 2006 to 2010 for the period October to February) were analyzed using state of the art software ENVI 4.2 and ArcGIS 10.2. This process resulted in area belonging to each class that is; haze, smog and fog. On the basis of density, haze and fog cover was determined. Variations in fog cover, its density and identification of location of fog initiation process were also determined using near real time (30 minutes) METEOSAT-7 IODC data where actually fog formation started and then extended to the area of favorable conditions. Haze has been noticed to intensify due to massive burning of agricultural waste (rice husk) in India and Pakistan towards the end of October each year. MODIS thermal anomalies/fire data (MYD 14) were also used to verify this activity on the ground, which results in hazy conditions at regional level during fall months. Haze-affected area during 2006 to 2010 in Pakistan ranged from 155,000 Km2 to 354,000 Km2 and in India it ranged from 333,000 Km2 to 846,000 Km2. Similarly winter fog cover during this period in Pakistan varied from 136,000 Km2 to 381,000 Km2 and in India it was estimated at 327,000 Km2 to 566,000 Km2. This phenomenon was more prominent in India than in Pakistan where and fog cover was at least twice than that was observed in Pakistan. It has been noted that area covered by fog, smog and haze doubled during the study period in the region. Atmospheric dimming during autumn/ fall also reduces the mixing height leading to greater pollutants accumulation. So far no mitigation steps have been taken to combat this regional issue. Reduction in local emissions is highly recommended to save at least the lives of vulnerable (children, elderly, patients etc).

  13. Career Education Programs for Educable Mentally Retarded. Info-Pak 2, Selected Readings.

    ERIC Educational Resources Information Center

    Michigan State Univ., East Lansing. Regional Instructional Materials Center for Handicapped Children and Youth.

    The information packet contains six abridged readings on career education programs for educable mentally retarded (EMR) adolescents and young adults. A driver training program is discussed which serves special needs of EMR students and is based on the premise that travel independence provides more vocational opportunity. A guidebook presents facts…

  14. The Education of Parents of Handicapped Children. Info-Pak 1, Selected Readings.

    ERIC Educational Resources Information Center

    Michigan State Univ., East Lansing. Regional Instructional Materials Center for Handicapped Children and Youth.

    The information packet contains six abridged readings on the education of parents of retarded or disadvantaged children. Specific teaching techniques such as recognizing individual performance levels are offered to maximize retarded children's learning. A handbook on parent councils discusses parent involvement in school programs for disadvantaged…

  15. ENVIRONMENTAL TECHNOLOGY VERIFICATION REPORT: PAINT OVERSPRAY ARRESTOR, AAF INTERNATIONAL DRI-PAK 40-45%

    EPA Science Inventory

    Paint overspray arrestors (POAs) were evaluated by the Air Pollution Control Technology (APCT) pilot of the Environmental Technology Verification (ETV) Program. The performance factor verified was the particle filtration efficiency as a function of size for particles smaller than...

  16. ENVIRONMENTAL TECHNOLOGY VERIFICATION REPORT, PAINT OVERSPRAY ARRESTOR, KOCH FILTER CORPORATION, DUO-PAK 650

    EPA Science Inventory

    Paint overspray arrestors (POAs) were evaluated by the Air Pollution Control Technology (APCT) pilot of the Environmental Technology Verification (ETV) Program. The performance factor verified was the particle filtration efficiency as a function of size for particles smaller than...

  17. VizieR Online Data Catalog: Early-type galaxies in Ursa Major cluster (Pak+, 2014)

    NASA Astrophysics Data System (ADS)

    Pak, M.; Rey, S.-C.; Lisker, T.; Lee, Y.; Kim, S.; Sung, E.-C.; Jerjen, H.; Chung, J.

    2015-04-01

    Our sample in the Ursa Major cluster is predominantly based on the SDSS Data Release 7 (DR7; Abazajian et al., 2009ApJS..182..543A). In order to investigate the ultraviolet properties of our sample galaxies in the Ursa Major cluster, we used far-ultraviolet (FUV, 1350-1750Å) and near-ultraviolet (NUV, 1750-2750Å) images from the GALEX GR6. (1 data file).

  18. STS-93 Columbia, Fit Check and Pre Pak in the O&C for Chandra

    NASA Technical Reports Server (NTRS)

    1999-01-01

    The primary objective of the STS-93 mission was to deploy the Advanced X-ray Astrophysical Facility, which had been renamed the Chandra X-ray Observatory in honor of the late Indian-American Nobel Laureate Subrahmanyan Chandrasekhar. The mission was launched at 12:31 on July 23, 1999 onboard the space shuttle Columbia. The mission was led by Commander Eileen Collins. The crew was Pilot Jeff Ashby and Mission Specialists Cady Coleman, Steve Hawley and Michel Tognini from the Centre National d'Etudes Spatiales (CNES). This videotape shows the astronauts getting into spacesuits, and inspecting the equipment.

  19. UTILIZING THE PAKS METHOD FOR MEASURING ACROLEIN AND OTHER ALDEHYDES IN DEARS

    EPA Science Inventory

    Acrolein is a hazardous air pollutant of high priority due to its high irritation potency and other potential adverse health effects. However, a reliable method is currently unavailable for measuring airborne acrolein at typical environmental levels. In the Detroit Exposure and A...

  20. Changes in the distributions of juvenile horseshoe crabs (Arthropoda: Chelicerata) (2002-2014) related to environmental perturbations at Pak Nai and Ha Pak Nai, Deep Bay, Hong Kong SAR, China.

    PubMed

    Lee, Christine Nga-Wing; Morton, Brian

    2016-07-15

    A survey of juvenile Asian horseshoe crabs in 2002 on the mudflats along Hong Kong's north-western shoreline abutting Deep Bay identified two species, Tachypleus tridentatus and Carcinoscorpius rotundicauda, and assessed their population characteristics. Since the 2002 survey, there have been significant habitat changes to this natal site for the two species. By employing the same, but expanded, sampling protocol, a further survey was, therefore, conducted twelve years later in 2014. A general population decline was recorded for T. tridentatus whereas for C. rotundicauda there was an increase and its distribution had become more widespread. The distribution patterns of the two species were also shown to have changed. The potential factors that might be responsible for recorded changes in the species' population characteristics between 2002 and 2014 are related to anthropogenic perturbations, including environmental habitat alterations notably the building of a bridge linking Hong Kong to Shenzhen in China. PMID:27158048

  1. Dynamic and thermodynamic response of the Ras protein Cdc42Hs upon association with the effector domain of PAK3.

    PubMed

    Moorman, Veronica R; Valentine, Kathleen G; Bédard, Sabrina; Kasinath, Vignesh; Dogan, Jakob; Love, Fiona M; Wand, A Joshua

    2014-10-23

    Human cell division cycle protein 42 (Cdc42Hs) is a small, Rho-type guanosine triphosphatase involved in multiple cellular processes through its interactions with downstream effectors. The binding domain of one such effector, the actin cytoskeleton-regulating p21-activated kinase 3, is known as PBD46. Nitrogen-15 backbone and carbon-13 methyl NMR relaxation was measured to investigate the dynamical changes in activated GMPPCP·Cdc42Hs upon PBD46 binding. Changes in internal motion of the Cdc42Hs, as revealed by methyl axis order parameters, were observed not only near the Cdc42Hs-PBD46 interface but also in remote sites on the Cdc42Hs molecule. The binding-induced changes in side-chain dynamics propagate along the long axis of Cdc42Hs away from the site of PBD46 binding with sharp distance dependence. Overall, the binding of the PBD46 effector domain on the dynamics of methyl-bearing side chains of Cdc42Hs results in a modest rigidification, which is estimated to correspond to an unfavorable change in conformational entropy of approximately -10kcalmol(-1) at 298K. A cluster of methyl probes closest to the nucleotide-binding pocket of Cdc42Hs becomes more rigid upon binding of PBD46 and is proposed to slow the catalytic hydrolysis of the γ phosphate moiety. An additional cluster of methyl probes surrounding the guanine ring becomes more flexible on binding of PBD46, presumably facilitating nucleotide exchange mediated by a guanosine exchange factor. In addition, the Rho insert helix, which is located at a site remote from the PBD46 binding interface, shows a significant dynamic response to PBD46 binding. PMID:25109462

  2. Photocatalytic degradation of acephate in pak choi, Brassica chinensis, with Ce-doped TiO2.

    PubMed

    Liu, Xiangying; Wang, Lifeng; Zhou, Xiaomao; Liu, Kailin; Bai, Lianyang; Zhou, Xuguo

    2015-01-01

    The photocatalytic degradation of acephate was investigated using Ce-doped TiO2 (TiO2/Ce) hydrosol. In contrast to previous research conducted under artificial light in the laboratory, this study investigated the decomposition of acephate in a field trial. The results show that acephate can be efficiently degraded by the TiO2/Ce system under natural field conditions; the degradation efficiency was affected by the dosage of the photocatalyst and acephate. The optimum dosage of TiO2/Ce was 2400 g a.i.ha(-1), and the photodegradation efficiency of acephate reached 93.5% after 20 h at an acephate dosage of 675 g a.i.ha(-1). Ultra-performance liquid chromatography/mass spectrometry (UPLC/MS) analysis detected and identified four degradation products-methamidophos, phosphorothioic acid O,O,S-trimethyl ester, S-methyl methanethiosulfonate and phosphorous acid-that were formed during the TiO2/Ce photodegradation of acephate. Based on the structural identification of the degradation products, a probable photodegradation pathway was proposed, and the first decomposition step may be the cleavage of the C‒N bond of acephate. Subsequently, the P‒S and P‒O bonds may be oxidized gradually or simultaneously to complete the mineralization. PMID:25826101

  3. Bomb blast injuries: an exploration of patient characteristics and outcome using Pakistan National Emergency Departments Surveillance (Pak-NEDS) data

    PubMed Central

    2015-01-01

    Background Bomb blast injuries result in premature deaths and burdening of healthcare systems. The objective of this study was to explore the characteristics and outcome of patients presenting to the emergency departments in Pakistan with bomb blast injuries. Methods Active surveillance was conducted in seven major emergency departments of Pakistan from November 2010-March 2011. All the sites are tertiary care urban centers. All the patients who presented to the hospital's emergency department (ED) following a bomb blast injury as per self-report or the ambulance personnel were included in the study. Frequency of demographics, injury pattern, and outcomes were calculated. Results A total of 103 patients with bomb blast injuries presented to the selected emergency departments. The median age of patients was 30 years. Around three-fourth of the patients were males (n = 74, 74.7%). Most of the bomb blast patients were seen in Peshawar (n = 41, 39.8%) and Karachi city (n = 31, 30.1%) and the most common mode of arrival was non-ambulance transport (n = 71, 76.3%). Upper limb injuries (n = 12, 40%) were common in the under 18 age group and lower limb injuries (n = 31, 39.2%) in the 18 years and above group. There were a total of 8 (7.7%) deaths reported out of these 103 patients. Conclusion Bomb blast injuries in Pakistan generally affect young males. Non-ambulance transport is the most common way to access emergency departments (ED). Overall ED mortality is high and capturing data during a disaster in an emergency department is challenging. PMID:26692453

  4. Cooperative measures to support the Indo-Pak Agreement Reducing Risk from Accidents Relating to Nuclear Weapons.

    SciTech Connect

    Mishra, Sitakanta; Ahmed, Mansoor

    2014-04-01

    In 2012, India and Pakistan reaffirmed the Agreement on Reducing the Risk from Accidents Relating to Nuclear Weapons. Despite a history of mutual animosity and persistent conflict between the two countries, this agreement derives strength from a few successful nuclear confidence building measures that have stood the test of time. It also rests on the hope that the region would be spared a nuclear holocaust from an accidental nuclear weapon detonation that might be misconstrued as a deliberate use of a weapon by the other side. This study brings together two emerging strategic analysts from South Asia to explore measures to support the Agreement and further develop cooperation around this critical issue. This study briefly dwells upon the strategic landscape of nuclear South Asia with the respective nuclear force management structures, doctrines, and postures of India and Pakistan. It outlines the measures in place for the physical protection and safety of nuclear warheads, nuclear materials, and command and control mechanisms in the two countries, and it goes on to identify the prominent, emerging challenges posed by the introduction of new weapon technologies and modernization of the respective strategic forces. This is followed by an analysis of the agreement itself leading up to a proposed framework for cooperative measures that might enhance the spirit and implementation of the agreement.

  5. Group II p21-activated kinases as therapeutic targets in gastrointestinal cancer

    PubMed Central

    Shao, Yang-Guang; Ning, Ke; Li, Feng

    2016-01-01

    P21-activated kinases (PAKs) are central players in various oncogenic signaling pathways. The six PAK family members are classified into group I (PAK1-3) and group II (PAK4-6). Focus is currently shifting from group I PAKs to group II PAKs. Group II PAKs play important roles in many fundamental cellular processes, some of which have particular significance in the development and progression of cancer. Because of their important functions, group II PAKs have become popular potential drug target candidates. However, few group II PAKs inhibitors have been reported, and most do not exhibit satisfactory kinase selectivity and “drug-like” properties. Isoform- and kinase-selective PAK inhibitors remain to be developed. This review describes the biological activities of group II PAKs, the importance of group II PAKs in the development and progression of gastrointestinal cancer, and small-molecule inhibitors of group II PAKs for the treatment of cancer. PMID:26811660

  6. Beilstein Without Tears: Education in the Use of the Literature of Organic Chemistry.

    ERIC Educational Resources Information Center

    Callaghan, Patricia M.; And Others

    1986-01-01

    The use of Beilstein ("Handbuch der Organischen Chemie") in the early stages of a second-year, one semester course in organic chemistry is described. Student literature projects, evaluation, use of ancillary literature, and a sample search are included. (JN)

  7. Resolution of long-standing necrobiosis lipoidica diabeticorum (NLD) lesion after restoration of euglycemia following successful pancreas after kidney (PAK) transplantation: a case report.

    PubMed

    Mazur, M J; Lowney, A C; Prigoff, J; Heilman, R L; Chakkera, H; Moss, A; Mulligan, D; Reddy, K; Hamawi, K

    2011-11-01

    Necrobiosis lipoidica diabeticorum (NLD) is an inflammatory skin disorder of unknown cause which can be seen in patients with diabetes mellitus. Various treatments, including immunosuppressive agents have been tried, without consistent efficacy. NLD is generally thought not to correlate well with tight diabetic control. Pancreas transplantation is the only widely and clinically used treatment that restores euglycemia in type I diabetic recipients. We report a case of resolution of NLD that had been unchanged for decades before pancreas after kidney transplantation. Another unique aspect of our case was that immunosuppression was discounted as a confounding factor, because the patient had been exposed to the same antirejection regimen for 3 years preceding the pancreas transplantation. PMID:22099781

  8. An isoform-selective, small-molecule inhibitor targets the autoregulatory mechanism of p21-activated kinase

    PubMed Central

    Deacon, Sean W.; Beeser, Alexander; Fukui, Jami A.; Rennefahrt, Ulrike E. E.; Myers, Cynthia; Chernoff, Jonathan; Peterson, Jeffrey R.

    2015-01-01

    SUMMARY Autoregulatory domains found within kinases may provide more unique targets for chemical inhibitors than the conserved ATP-binding pocket targeted by most inhibitors. The kinase Pak1 contains an autoinhibitory domain that suppresses the catalytic activity of its kinase domain. Pak1 activators relieve this autoinhibition and initiate conformational rearrangements and autophosphorylation events leading to kinase activation. We developed a screen for allosteric inhibitors targeting Pak1 activation and identified the inhibitor IPA-3. Remarkably, pre-activated Pak1 is resistant to IPA-3. IPA-3 also inhibits activation of related Pak isoforms regulated by autoinhibition, but not more distantly related Paks, nor >200 other kinases tested. Pak1 inhibition by IPA-3 in live cells supports a critical role for Pak in PDGF-stimulated Erk activation. These studies illustrate a novel strategy for kinase inhibition and introduce a highly selective, cell-permeable chemical inhibitor of Pak. PMID:18420139

  9. Small molecules that allosterically inhibit p21-activated kinase activity by binding to the regulatory p21-binding domain.

    PubMed

    Kim, Duk-Joong; Choi, Chang-Ki; Lee, Chan-Soo; Park, Mee-Hee; Tian, Xizhe; Kim, Nam Doo; Lee, Kee-In; Choi, Joong-Kwon; Ahn, Jin Hee; Shin, Eun-Young; Shin, Injae; Kim, Eung-Gook

    2016-01-01

    p21-activated kinases (PAKs) are key regulators of actin dynamics, cell proliferation and cell survival. Deregulation of PAK activity contributes to the pathogenesis of various human diseases, including cancer and neurological disorders. Using an ELISA-based screening protocol, we identified naphtho(hydro)quinone-based small molecules that allosterically inhibit PAK activity. These molecules interfere with the interactions between the p21-binding domain (PBD) of PAK1 and Rho GTPases by binding to the PBD. Importantly, they inhibit the activity of full-length PAKs and are selective for PAK1 and PAK3 in vitro and in living cells. These compounds may potentially be useful for determining the details of the PAK signaling pathway and may also be used as lead molecules in the development of more selective and potent PAK inhibitors. PMID:27126178

  10. Small molecules that allosterically inhibit p21-activated kinase activity by binding to the regulatory p21-binding domain

    PubMed Central

    Kim, Duk-Joong; Choi, Chang-Ki; Lee, Chan-Soo; Park, Mee-Hee; Tian, Xizhe; Kim, Nam Doo; Lee, Kee-In; Choi, Joong-Kwon; Ahn, Jin Hee; Shin, Eun-Young; Shin, Injae; Kim, Eung-Gook

    2016-01-01

    p21-activated kinases (PAKs) are key regulators of actin dynamics, cell proliferation and cell survival. Deregulation of PAK activity contributes to the pathogenesis of various human diseases, including cancer and neurological disorders. Using an ELISA-based screening protocol, we identified naphtho(hydro)quinone-based small molecules that allosterically inhibit PAK activity. These molecules interfere with the interactions between the p21-binding domain (PBD) of PAK1 and Rho GTPases by binding to the PBD. Importantly, they inhibit the activity of full-length PAKs and are selective for PAK1 and PAK3 in vitro and in living cells. These compounds may potentially be useful for determining the details of the PAK signaling pathway and may also be used as lead molecules in the development of more selective and potent PAK inhibitors. PMID:27126178

  11. p21-Activated Kinase 2 Regulates Endothelial Development and Function through the Bmk1/Erk5 Pathway

    PubMed Central

    Radu, Maria; Lyle, Karen; Hoeflich, Klaus P.; Villamar-Cruz, Olga; Koeppen, Hartmut

    2015-01-01

    p21-activated kinases (Paks) have been shown to regulate cytoskeleton rearrangements, cell proliferation, attachment, and migration in a variety of cellular contexts, including endothelial cells. However, the role of endothelial Pak in embryo development has not been reported, and currently, there is no consensus on the endothelial function of individual Pak isoforms, in particular p21-activated kinase 2 (Pak2), the main Pak isoform expressed in endothelial cells. In this work, we employ genetic and molecular studies that show that Pak2, but not Pak1, is a critical mediator of development and maintenance of endothelial cell function. Endothelial depletion of Pak2 leads to early embryo lethality due to flawed blood vessel formation in the embryo body and yolk sac. In adult endothelial cells, Pak2 depletion leads to severe apoptosis and acute angiogenesis defects, and in adult mice, endothelial Pak2 deletion leads to increased vascular permeability. Furthermore, ubiquitous Pak2 deletion is lethal in adult mice. We show that many of these defects are mediated through a newly unveiled Pak2/Bmk1 pathway. Our results demonstrate that endothelial Pak2 is essential during embryogenesis and also for adult blood vessel maintenance, and they also pinpoint the Bmk1/Erk5 pathway as a critical mediator of endothelial Pak2 signaling. PMID:26391956

  12. P21-activated kinase in inflammatory and cardiovascular disease

    PubMed Central

    Taglieri, Domenico M.; Ushio-Fukai, Masuko; Monasky, Michelle M.

    2014-01-01

    P-21 activated kinases, or PAKs, are serine–threonine kinases that serve a role in diverse biological functions and organ system diseases. Although PAK signaling has been the focus of many investigations, still our understanding of the role of PAK in inflammation is incomplete. This review consolidates what is known about PAK1 across several cell types, highlighting the role of PAK1 and PAK2 in inflammation in relation to NADPH oxidase activation. This review explores the physiological functions of PAK during inflammation, the role of PAK in several organ diseases with an emphasis on cardiovascular disease, and the PAK signaling pathway, including activators and targets of PAK. Also, we discuss PAK1 as a pharmacological anti-inflammatory target, explore the potentials and the limitations of the current pharmacological tools to regulate PAK1 activity during inflammation, and provide indications for future research. We conclude that a vast amount of evidence supports the idea that PAK is a central molecule in inflammatory signaling, thus making PAK1 itself a promising prospective pharmacological target. PMID:24794532

  13. p21-activated kinase 2 regulates HSPC cytoskeleton, migration, and homing via CDC42 activation and interaction with β-Pix.

    PubMed

    Reddy, Pavankumar N G; Radu, Maria; Xu, Ke; Wood, Jenna; Harris, Chad E; Chernoff, Jonathan; Williams, David A

    2016-04-21

    Cytoskeletal remodeling of hematopoietic stem and progenitor cells (HSPCs) is essential for homing to the bone marrow (BM). The Ras-related C3 botulinum toxin substrate (Rac)/cell division control protein 42 homolog (CDC42) effector p21-activated kinase (Pak2) has been implicated in HSPC homing and engraftment. However, the molecular pathways mediating Pak2 functions in HSPCs are unknown. Here, we demonstrate that both Pak2 kinase activity and its interaction with the PAK-interacting exchange factor-β (β-Pix) are required to reconstitute defective ITALIC! Pak2 (ITALIC! Δ/Δ)HSPC homing to the BM. Pak2 serine/threonine kinase activity is required for stromal-derived factor-1 (SDF1α) chemokine-induced HSPC directional migration, whereas Pak2 interaction with β-Pix is required to regulate the velocity of HSPC migration and precise F-actin assembly. Lack of SDF1α-induced filopodia and associated abnormal cell protrusions seen in ITALIC! Pak2 (ITALIC! Δ/Δ)HSPCs were rescued by wild-type (WT) Pak2 but not by a Pak2-kinase dead mutant (KD). Expression of a β-Pix interaction-defective mutant of Pak2 rescued filopodia formation but led to abnormal F-actin bundles. Although CDC42 has previously been considered an upstream regulator of Pak2, we found a paradoxical decrease in baseline activation of CDC42 in ITALIC! Pak2 (ITALIC! Δ/Δ)HSPCs, which was rescued by expression of Pak2-WT but not by Pak2-KD; defective homing of ITALIC! Pak2-deleted HSPCs was rescued by constitutive active CDC42. These data demonstrate that both Pak2 kinase activity and its interaction with β-Pix are essential for HSPC filopodia formation, cytoskeletal integrity, and homing via activation of CDC42. Taken together, we provide mechanistic insights into the role of Pak2 in HSPC migration and homing. PMID:26932803

  14. p21-activated kinase 1 determines stem-like phenotype and sunitinib resistance via NF-κB/IL-6 activation in renal cell carcinoma

    PubMed Central

    Zhu, Y; Liu, H; Xu, L; An, H; Liu, W; Liu, Y; Lin, Z; Xu, J

    2015-01-01

    The p21-activated kinase 1 (PAK1), a serine/threonine kinase that orchestrates cytoskeletal remodeling and cell motility, has been shown to function as downstream node for various oncogenic signaling pathways to promote cell proliferation, regulate apoptosis and accelerate mitotic abnormalities, resulting in tumor formation and invasiveness. Although alterations in PAK1 expression and activity have been detected in various human malignancies, its potential biological and clinical significance in renal cell carcinoma (RCC) remains obscure. In this study, we found increased PAK1 and phosphorylated PAK1 levels in tumor tissues according to TNM stage progression. Elevated phosphorylated PAK1 levels associated with progressive features and indicated unfavorable overall survival (OS) as an independent adverse prognosticator for patients with RCC. Moreover, PAK1 kinase activation with constitutive active PAK1 mutant T423E promoted growth, colony formation, migration, invasion and stem-like phenotype of RCC cells, and vice versa, in PAK1 inhibition by PAK1 kinase inactivation with specific PAK1 shRNA, dead kinase PAK1 mutant K299R or allosteric inhibitor IPA3. Stem-like phenotype due to sunitinib administration via increased PAK1 kinase activation could be ameliorated by PAK1 shRNA, PAK1 mutant K299R and IPA3. Furthermore, nuclear factor-κB (NF-κB)/interleukin-6 (IL-6) activation was found to be responsible for PAK1-mediated stem-like phenotype following sunitinib treatment. Both IL-6 neutralizing antibody and IPA3 administration enhanced tumor growth inhibition effect of sunitinib treatment on RCC cells in vitro and in vivo. Our results unraveled that oncogenic activation of PAK1 defines an important mechanism for maintaining stem-like phenotype and sunitinib resistance through NF-κB/IL-6 activation in RCC, lending PAK1-mediated NF-κB/IL-6 activation considerable appeal as novel pharmacological therapeutic targets against sunitinib resistance. PMID:25675297

  15. Heat sinking for printed circuitry

    DOEpatents

    Wilson, S.K.; Richardson, G.; Pinkerton, A.L.

    1984-09-11

    A flat pak or other solid-state device mounted on a printed circuit board directly over a hole extends therethrough so that the bottom of the pak or device extends beyond the bottom of the circuit board. A heat sink disposed beneath the circuit board contacts the bottom of the pak or device and provides direct heat sinking thereto. Pressure may be applied to the top of the pak or device to assure good mechanical and thermal contact with the heat sink.

  16. Elevated p21-activated kinase 2 activity results in anchorage-independent growth and resistance to anticancer drug-induced cell death.

    PubMed

    Marlin, Jerry W; Eaton, Andrew; Montano, Gerald T; Chang, Yu-Wen E; Jakobi, Rolf

    2009-03-01

    p21-activated kinase 2 (PAK-2) seems to be a regulatory switch between cell survival and cell death signaling. We have shown previously that activation of full-length PAK-2 by Rac or Cdc42 stimulates cell survival, whereas caspase activation of PAK-2 to the proapoptotic PAK-2p34 fragment is involved in the cell death response. In this study, we present a role of elevated activity of full-length PAK-2 in anchorage-independent growth and resistance to anticancer drug-induced apoptosis of cancer cells. Hs578T human breast cancer cells that have low levels of PAK-2 activity were more sensitive to anticancer drug-induced apoptosis and showed higher levels of caspase activation of PAK-2 than MDA-MB435 and MCF-7 human breast cancer cells that have high levels of PAK-2 activity. To examine the role of elevated PAK-2 activity in breast cancer, we have introduced a conditionally active PAK-2 into Hs578T human breast cells. Conditional activation of PAK-2 causes loss of contact inhibition and anchorage-independent growth of Hs578T cells. Furthermore, conditional activation of PAK-2 suppresses activation of caspase 3, caspase activation of PAK-2, and apoptosis of Hs578T cells in response to the anticancer drug cisplatin. Our data suggest a novel mechanism by which full-length PAK-2 activity controls the apoptotic response by regulating levels of activated caspase 3 and thereby its own cleavage to the proapoptotic PAK-2p34 fragment. As a result, elevated PAK-2 activity interrupts the apoptotic response and thereby causes anchorage-independent survival and growth and resistance to anticancer drug-induced apoptosis. PMID:19242610

  17. Redundant canonical and noncanonical Caenorhabditis elegans p21-activated kinase signaling governs distal tip cell migrations.

    PubMed

    Peters, Eldon C; Gossett, Andrea J; Goldstein, Bob; Der, Channing J; Reiner, David J

    2013-02-01

    p21-activated kinases (Paks) are prominent mediators of Rac/Cdc42-dependent and -independent signaling and regulate signal transduction and cytoskeletal-based cell movements. We used the reproducible migrations of the Caenorhabditis elegans gonadal distal tip cells to show that two of the three nematode Pak proteins, MAX-2 and PAK-1, function redundantly in regulation of cell migration but are regulated by very different mechanisms. First, we suggest that MAX-2 requires CED-10/Rac function and thus functions canonically. Second, PIX-1 and GIT-1 function in the same role as PAK-1, and PAK-1 interaction with PIX-1 is required for PAK-1 activity; thus, PAK-1 functions noncanonically. The human Pak-Pix-Git complex is central to noncanonical Pak signaling and requires only modest Rac/CDC-42 input. Unlike the human complex, our results suggest that the C. elegans Pak-Pix-Git complex requires PAK-1 kinase domain activity. This study delineates signaling network relationships in this cell migration model, thus providing potential further mechanistic insights and an assessment of total Pak contribution to cell migration events. PMID:23390595

  18. Expression of p21-activated kinases 1 and 3 is altered in the brain of subjects with depression.

    PubMed

    Fuchsova, Beata; Alvarez Juliá, Anabel; Rizavi, Hooriyah S; Frasch, Alberto Carlos; Pandey, Ghanshyam N

    2016-10-01

    The p21-activated kinases (PAKs) of group I are the main effectors for the small Rho GTPases, critically involved in neurodevelopment, plasticity and maturation of the nervous system. Moreover, the neuronal complexity controlled by PAK1/PAK3 signaling determines the postnatal brain size and synaptic properties. Stress induces alterations at the level of structural and functional synaptic plasticity accompanied by reductions in size and activity of the hippocampus and the prefrontal cortex (PFC). These abnormalities are likely to contribute to the pathology of depression and, in part, reflect impaired cytoskeleton remodeling pointing to the role of Rho GTPase signaling. Thus, the present study assessed the expression of the group I PAKs and their activators in the brain of depressed subjects. Using quantitative polymerase chain reaction (qPCR), mRNA levels and coexpression of the group I PAKs: PAK1, PAK2, and PAK3 as well as of their activators: RAC1, CDC42 and ARHGEF7 were examined in postmortem samples from the PFC (n=25) and the hippocampus (n=23) of subjects with depression and compared to control subjects (PFC n=24; hippocampus n=21). Results demonstrated that mRNA levels of PAK1 and PAK3, are significantly reduced in the brain of depressed subjects, with PAK1 being reduced in the PFC and PAK3 in the hippocampus. No differences were observed for the ubiquitously expressed PAK2. Following analysis of gene coexpression demonstrated disruption of coordinated gene expression in the brain of subjects with depression. Abnormalities in mRNA expression of PAK1 and PAK3 as well as their altered coexpression patterns were detected in the brain of subjects with depression. PMID:27474226

  19. New system enables fleets to tailor maintenance programs

    SciTech Connect

    Fiscor, S.

    2007-08-15

    The Lubrizol Corporation has developed FluiPak and FluiPak Lite systems to pull engine oils and sample them continuously, helping to maintain mining equipment between oil change intervals. The FluiPak system has a control box, a sensor box and a reserve system. FluiPak Lite is simply a cut-down version of FluiPak. The article explains how the system works to detect in real time oil quality and contaminants and hence optimize drain intervals and also prolong engine component life and reduce waste oil disposal costs. 100 units are currently installed in coal operations. 5 figs., 5 photos.

  20. Signaling-dependent Phosphorylation of Mitotic Centromere-associated Kinesin Regulates Microtubule Depolymerization and Its Centrosomal Localization*

    PubMed Central

    Pakala, Suresh B.; Nair, Vasudha S.; Reddy, Sirigiri DivijendraNatha; Kumar, Rakesh

    2012-01-01

    Although p21-activated kinase 1 (PAK1) and microtubule (MT) dynamics regulate numerous fundamental processes including cytoskeleton remodeling, directional motility, and mitotic functions, the significance of PAK1 signaling in regulating the functions of MT-destabilizing protein mitotic centromere-associated kinesin (MCAK) remains unknown. Here we found that MCAK is a cognate substrate of PAK1 wherein PAK1 phosphorylates MCAK on serines 192 and 111 both in vivo and in vitro. Furthermore, we found that PAK1 phosphorylation of MCAK on serines 192 and 111 preferentially regulates its microtubule depolymerization activity and localization to centrosomes, respectively, in the mammalian cells. PMID:23055517

  1. Effects of p21-activated kinase 1 inhibition on 11q13-amplified ovarian cancer cells.

    PubMed

    Prudnikova, T Y; Villamar-Cruz, O; Rawat, S J; Cai, K Q; Chernoff, J

    2016-04-28

    p21-activated kinases (Paks) are Cdc42/Rac-activated serine-threonine protein kinases that regulate several key cancer-relevant signaling pathways, such as the Mek/Erk, PI3K/Akt and Wnt/b-catenin signaling pathways. Pak1 is frequently overexpressed and/or hyperactivated in different human cancers, including human breast, ovary, prostate and brain cancer, due to amplification of the PAK1 gene in an 11q13 amplicon. Genetic or pharmacological inactivation of Pak1 has been shown to reduce proliferation of different cancer cells in vitro and reduce tumor progression in vivo. In this work, we examined the roles of Pak1 in cellular and animal models of PAK1-amplified ovarian cancer. We found that inhibition of Pak1 leads to decreased proliferation and migration in PAK1-amplified/overexpressed ovarian cancer cells, and has no effect in cell that lack such amplification/overexpression. Further, we observed that loss of Pak1 function causes 11q13-amplified ovarian cancer cells to arrest in the G2/M phase of the cell cycle. This arrest correlates with activation of p53 and p21(Cip) and decreased expression of cyclin B1. These findings suggest that small-molecule inhibitors of Pak1 may have a therapeutic role in the ~25% of ovarian cancers characterized by PAK1 gene amplification. PMID:26257058

  2. Interferences of atmospheric oxidants in the sampling of aldehydes using sep pak C18 mciro columns coated wtih 2,4-DNPH: The use of cellulose filters coated with KI as a scrubber

    SciTech Connect

    Andrade, J.B. de; Andrade, V.A.S. de; Pinheiro, H.L.C.

    1995-12-01

    Measurements of formaldehyde and acetaldehyde in the atmosphere often involve the use of DNPH-coated cartridges. During sampling, ozone and other atmospheric oxidants may react with DNPH and/or the carbonyl-DNPH, thus resulting in a negative bias. In this study, ambient air has been collected using co-located DNPH C{sub 18} cartridges with and without a filter coated with KI to remove ozone and other oxidants. Concentrations of formaldehyde and acetaldehyde measured without the KI filter were lower than those measured with a KI filter. Implications for ambient measurements of carbonyls in the presence of atmospheric ozone are discussed.

  3. Interdisciplinary Educational Collaborations: Chemistry and Computer Science 967 Ronald S. Haines, Daniel T. Woo, Benjamin T. Hudson, Joji C. Mori, Evey S. M. Ngan, and Wing-Yee Pak

    NASA Astrophysics Data System (ADS)

    Goedhart, Martin J.

    2007-06-01

    While chemists are usually aware of the possibilities of interdisciplinary collaboration in chemical research they may be less aware of the possibilities of such collaboration in education. This article documents an ongoing collaboration between a chemist and computer scientist to co-supervise computer science students engaged in developing software for chemical education, highlights the benefits to both the chemistry and computer science students, notes some unexpected outcomes, and provides guidance to those planning such collaborations. The experiences described in this work should motivate chemistry educators to approach their colleagues in other disciplines with proposals for joint research projects. The collaboration described here initially resulted in the development of student-friendly software for operating a spectrophotometer. Recent co-supervised students have begun developing other software for chemical education.

  4. OHMSETT (OIL AND HAZARDOUS MATERIALS SIMULATED ENVIRONMENTAL TEST TANK) TEST SERIES 77: GLOBAL OIL RECOVERY SKIMMER, VEEGARM SKIMMING ARM, KEBAB 600, WYLIE SKIMMER AND THE SKIM-PAK CLUSTER

    EPA Science Inventory

    This report covers the performance testing of five oil spill recovery devices at the Oil and Hazardous Materials Simulated Environmental Test Tank in Leonardo, New Jersey. The GOR Skimmer was tow tested in harbor chops, regular waves, and calm water at tow speeds through 2 knots ...

  5. Survival Escherichia coli O157:H7 transformed with either the pAK1-lux or pXEN-13 plasmids in in vitro bovine ruminal and fecal microbial fermentations

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The use of luminescent technology may serve as a viable model for the real-time validation of various pre-harvest interventions on the colonization or shedding of Escherichia coli O157:H7 within cattle. The objective of this study was to determine if the growth of E. coli O157:H7 (ATCC 43888) in ru...

  6. p21-activated kinase group II small compound inhibitor GNE-2861 perturbs estrogen receptor alpha signaling and restores tamoxifen-sensitivity in breast cancer cells

    PubMed Central

    Li, Zhilun; Lorent, Julie; Zhao, Chunyan; Dahlman-Wright, Karin; Strömblad, Staffan

    2015-01-01

    Estrogen receptor alpha (ERα) is highly expressed in most breast cancers. Consequently, ERα modulators, such as tamoxifen, are successful in breast cancer treatment, although tamoxifen resistance is commonly observed. While tamoxifen resistance may be caused by altered ERα signaling, the molecular mechanisms regulating ERα signaling and tamoxifen resistance are not entirely clear. Here, we found that PAK4 expression was consistently correlated to poor patient outcome in endocrine treated and tamoxifen-only treated breast cancer patients. Importantly, while PAK4 overexpression promoted tamoxifen resistance in MCF-7 human breast cancer cells, pharmacological treatment with a group II PAK (PAK4, 5, 6) inhibitor, GNE-2861, sensitized tamoxifen resistant MCF-7/LCC2 breast cancer cells to tamoxifen. Mechanistically, we identified a regulatory positive feedback loop, where ERα bound to the PAK4 gene, thereby promoting PAK4 expression, while PAK4 in turn stabilized the ERα protein, activated ERα transcriptional activity and ERα target gene expression. Further, PAK4 phosphorylated ERα-Ser305, a phosphorylation event needed for the PAK4 activation of ERα-dependent transcription. In conclusion, PAK4 may be a suitable target for perturbing ERα signaling and tamoxifen resistance in breast cancer patients. PMID:26554417

  7. Alphaherpesvirus US3-mediated reorganization of the actin cytoskeleton is mediated by group A p21-activated kinases

    PubMed Central

    Van den Broeke, Céline; Radu, Maria; Deruelle, Matthias; Nauwynck, Hans; Hofmann, Clemens; Jaffer, Zahara M.; Chernoff, Jonathan; Favoreel, Herman W.

    2009-01-01

    The US3 protein is a viral serine/threonine kinase that is conserved among all members of the Alphaherpesvirinae. The US3 protein of different alphaherpesviruses causes dramatic alterations in the actin cytoskeleton, such as the disassembly of actin stress fibers and formation of cell projections, which have been associated with increased intercellular virus spread. Here, we find that inhibiting group A p21-activated kinases (PAKs), which are key regulators in Cdc42/Rac1 Rho GTPase signaling pathways, impairs US3-mediated actin alterations. By using PAK1−/− and PAK2−/− mouse embryo fibroblasts (MEFs), we show that US3-mediated stress fiber disassembly requires PAK2, whereas US3-mediated cell projection formation mainly is mediated by PAK1, also indicating that PAK1 and PAK2 can have different biological effects on the organization of the actin cytoskeleton. In addition, US3 was found to bind and phosphorylate group A PAKs. Lack of group A PAKs in MEFs was correlated with inefficient virus spread. Thus, US3 induces its effect on the actin cytoskeleton via group A PAKs. PMID:19435845

  8. p21-activated kinase 4 critically regulates melanogenesis via activation of the CREB/MITF and β-catenin/MITF pathways.

    PubMed

    Yun, Cheong-Yong; You, Soon-Tae; Kim, Jin-Hwa; Chung, Jin H; Han, Sang-Bae; Shin, Eun-Young; Kim, Eung-Gook

    2015-05-01

    p21-activated kinase 4 (PAK4) regulates a wide range of cellular events, including cytoskeletal remodeling, cell growth, and survival. Our previous study identified PAK4 as a key regulator of cAMP-response element-binding protein (CREB) that acts upstream of microphthalmia-associated transcription factor (MITF), a master transcription factor in melanogenesis. We therefore investigated the role of PAK4 in melanogenesis. Melanocytes express both PAK2 and PAK4 isoforms, but only RNA interference knockdown of PAK4 significantly influenced α-melanocyte-stimulating hormone (α-MSH)-induced melanogenesis in B16 melanoma cells. Consistent with this result, PAK4 inhibition by PF3758309, a potent ATP-competitive inhibitor of PAKs, suppressed not only α-MSH-induced melanogenesis in B16 melanoma and human epithelial melanocyte cells but also UVB-induced melanogenesis in the skin of melanin-possessing hairless mice (HRM-2) in a dose-dependent manner. Inhibition of PAK4 over several days markedly decreased the levels of CREB, MITF, and tyrosinase in both HRM-2 mice and B16 melanoma cells. Moreover, PAK4 knockdown and inhibition suppressed α-MSH-stimulated β-catenin phosphorylation at serine 675 (S675) but enhanced phosphorylation at S33/37, an indicator for ubiquitination-dependent proteolysis. Together, our results provide evidence that PAK4 promotes α-MSH/UVB-induced melanogenesis via the CREB and Wnt/β-catenin signaling pathways and suggest that PAK4 may be a potential therapeutic target in pigmentation disorders. PMID:25560280

  9. Cytotaxonomy of Eurypyga helias (Gruiformes, Eurypygidae): First Karyotypic Description and Phylogenetic Proximity with Rynochetidae

    PubMed Central

    dos Santos, Michelly da Silva; Tagliarini, Marcella Mergulhão; O´Brien, Patricia C. M.; Ferguson-Smith, Malcolm A.; de Oliveira, Edivaldo H. C.

    2015-01-01

    The sunbittern (Eurypyga helias) is a South American Gruiformes, the only member of Family Eurypigidae. In most phylogenetic proposals, it is placed in a more distant position than other families of the so-called “core Gruiformes”. Different studies based on molecular, morphological and biogeographical data suggest that the Eurypigidae is closely related to the kagu (Rhynochetos jubatus), the only species in Rynochetidae, another family not included in the core Gruiformes. Here, the karyotype of the sunbittern is described for the first time, by classical and molecular cytogenetics, using whole chromosome probes derived from Gallus gallus and Leucopternis albicollis. We found a diploid number of 80, with only one pair of biarmed autosomal macrochromosomes, similar to that observed in the kagu. Chromosome painting revealed that most syntenies found in the avian putative ancestral karyotype (PAK) were conserved in the sunbittern. However, PAK1, PAK2, and PAK5 corresponded to two chromosome pairs each. Probes derived from L. albicollis confirm that fissions in PAK1 and PAK2 were centric, whereas in PAK5 the fission is interstitial. In addition, there is fusion of segments homologous to PAK2q and PAK5. From a phylogenetic point of view, comparisons of our results with two other Gruiformes belonging to family Rallidae suggest that the PAK5q fission might be a synapomorphy for Gruiformes. Fissions in PAK1 and PAK2 are found only in Eurypigidae, and might also occur in Rynochetidae, in view of the similar chromosomal morphology between the sunbittern and the kagu. This suggests a close phylogenetic relationship between Eurypigidae and Rynochetidae, whose common ancestor was separated by the Gondwana vicariancy in South America and New Caledonia, respectively. PMID:26624624

  10. Cytotaxonomy of Eurypyga helias (Gruiformes, Eurypygidae): First Karyotypic Description and Phylogenetic Proximity with Rynochetidae.

    PubMed

    Furo, Ivanete de Oliveira; Monte, Amanda Almeida; dos Santos, Michelly da Silva; Tagliarini, Marcella Mergulhão; O'Brien, Patricia C M; Ferguson-Smith, Malcolm A; de Oliveira, Edivaldo H C

    2015-01-01

    The sunbittern (Eurypyga helias) is a South American Gruiformes, the only member of Family Eurypigidae. In most phylogenetic proposals, it is placed in a more distant position than other families of the so-called "core Gruiformes". Different studies based on molecular, morphological and biogeographical data suggest that the Eurypigidae is closely related to the kagu (Rhynochetos jubatus), the only species in Rynochetidae, another family not included in the core Gruiformes. Here, the karyotype of the sunbittern is described for the first time, by classical and molecular cytogenetics, using whole chromosome probes derived from Gallus gallus and Leucopternis albicollis. We found a diploid number of 80, with only one pair of biarmed autosomal macrochromosomes, similar to that observed in the kagu. Chromosome painting revealed that most syntenies found in the avian putative ancestral karyotype (PAK) were conserved in the sunbittern. However, PAK1, PAK2, and PAK5 corresponded to two chromosome pairs each. Probes derived from L. albicollis confirm that fissions in PAK1 and PAK2 were centric, whereas in PAK5 the fission is interstitial. In addition, there is fusion of segments homologous to PAK2q and PAK5. From a phylogenetic point of view, comparisons of our results with two other Gruiformes belonging to family Rallidae suggest that the PAK5q fission might be a synapomorphy for Gruiformes. Fissions in PAK1 and PAK2 are found only in Eurypigidae, and might also occur in Rynochetidae, in view of the similar chromosomal morphology between the sunbittern and the kagu. This suggests a close phylogenetic relationship between Eurypigidae and Rynochetidae, whose common ancestor was separated by the Gondwana vicariancy in South America and New Caledonia, respectively. PMID:26624624

  11. The discovery and the structural basis of an imidazo[4,5-b]pyridine-based p21-activated kinase 4 inhibitor.

    PubMed

    Park, Jeung Kuk; Kim, Sunmin; Han, Yu Jin; Kim, Seong Hwan; Kang, Nam Sook; Lee, Hyuk; Park, SangYoun

    2016-06-01

    p21-Activated kinases (PAKs) which belong to the family of ste20 serine/threonine protein kinases regulate cytoskeletal reorganization, cell motility, cell proliferation, and oncogenic transformation which are all related to the cellular functions during cancer induction and metastasis. The fact that PAK mutations are detected in multiple tumor tissues makes PAKs a novel therapeutic drug target. In this study, an imidazo[4,5-b]pyridine-based PAK4 inhibitor, KY-04045 (6-Bromo-2-(3-isopropyl-1-methyl-1H-pyrazol-4-yl)-1H-imidazo[4,5-b]pyridine), was discovered using a virtual site-directed fragment-based drug design and was validated using an inhibition assay. Although PAK4 affinity to KY-04045 seems much weaker than that of the reported PAK4 inhibitors, the location of KY-04045 is clearly defined in the structure of PAK4 co-crystallized with KY-04045. The crystal structure illustrates that the pyrazole and imidazopyridine rings of KY-04045 are sufficient for mediating PAK4 hinge loop interaction. Hence, we believe that KY-04045 can be exploited as a basic building block in designing novel imidazo[4,5-b]pyridine-based PAK4 inhibitors. PMID:27117431

  12. Photovoltaik Hybrid-Solarzellen mit Nanopartikeln

    NASA Astrophysics Data System (ADS)

    Leute, Angelika

    2004-09-01

    Die organische Photovoltaik auf der Basis halbleitender Polymere bietet eine kostengünstige Alternative zu Solarzellen aus Silizium. Allerdings weisen die organischen Materialien relativ schlechte Ladungstransporteigenschaften auf. Hybrid-Solarzellen, in denen Polymere mit geeigneten anorganischen Halbleitern kombiniert sind, besitzen einerseits die praktischen Vorteile der Organik und andererseits die hohe Elektronenbeweglichkeit der anorganischen Materialien. Wissenschaftler der Technischen Universität Eindhoven haben kürzlich Hybrid-Solarzellen vorgestellt, die aus einem halbleitenden Polymer mit Zinkoxid-Nanopartikeln bestehen.

  13. Condensing Algebra for Technical Mathematics.

    ERIC Educational Resources Information Center

    Greenfield, Donald R.

    Twenty Algebra-Packets (A-PAKS) were developed by the investigator for technical education students at the community college level. Each packet contained a statement of rationale, learning objectives, performance activities, performance test, and performance test answer key. The A-PAKS condensed the usual sixteen weeks of algebra into a six-week…

  14. p21-Activated Kinase 1 Plays a Critical Role in Cellular Activation by Nef

    PubMed Central

    Fackler, Oliver T.; Lu, Xiaobin; Frost, Jeffrey A.; Geyer, Matthias; Jiang, Bing; Luo, Wen; Abo, Arie; Alberts, Arthur S.; Peterlin, B. Matija

    2000-01-01

    The activation of Nef-associated kinase (NAK) by Nef from human and simian immunodeficiency viruses is critical for efficient viral replication and pathogenesis. This induction occurs via the guanine nucleotide exchange factor Vav and the small GTPases Rac1 and Cdc42. In this study, we identified NAK as p21-activated kinase 1 (PAK1). PAK1 bound to Nef in vitro and in vivo. Moreover, the induction of cytoskeletal rearrangements such as the formation of trichopodia, the activation of Jun N-terminal kinase, and the increase of viral production were blocked by an inhibitory peptide that targets the kinase activity of PAK1 (PAK1 83-149). These results identify NAK as PAK1 and emphasize the central role its kinase activity plays in cytoskeletal rearrangements and cellular signaling by Nef. PMID:10713183

  15. Leucine-rich repeat kinase 2 interacts with p21-activated kinase 6 to control neurite complexity in mammalian brain.

    PubMed

    Civiero, Laura; Cirnaru, Maria Daniela; Beilina, Alexandra; Rodella, Umberto; Russo, Isabella; Belluzzi, Elisa; Lobbestael, Evy; Reyniers, Lauran; Hondhamuni, Geshanthi; Lewis, Patrick A; Van den Haute, Chris; Baekelandt, Veerle; Bandopadhyay, Rina; Bubacco, Luigi; Piccoli, Giovanni; Cookson, Mark R; Taymans, Jean-Marc; Greggio, Elisa

    2015-12-01

    Leucine-rich repeat kinase 2 (LRRK2) is a causative gene for Parkinson's disease, but the physiological function and the mechanism(s) by which the cellular activity of LRRK2 is regulated are poorly understood. Here, we identified p21-activated kinase 6 (PAK6) as a novel interactor of the GTPase/ROC domain of LRRK2. p21-activated kinases are serine-threonine kinases that serve as targets for the small GTP binding proteins Cdc42 and Rac1 and have been implicated in different morphogenetic processes through remodeling of the actin cytoskeleton such as synapse formation and neuritogenesis. Using an in vivo neuromorphology assay, we show that PAK6 is a positive regulator of neurite outgrowth and that LRRK2 is required for this function. Analyses of post-mortem brain tissue from idiopathic and LRRK2 G2019S carriers reveal an increase in PAK6 activation state, whereas knock-out LRRK2 mice display reduced PAK6 activation and phosphorylation of PAK6 substrates. Taken together, these results support a critical role of LRRK2 GTPase domain in cytoskeletal dynamics in vivo through the novel interactor PAK6, and provide a valuable platform to unravel the mechanism underlying LRRK2-mediated pathophysiology. We propose p21-activated kinase 6 (PAK6) as a novel interactor of leucine-rich repeat kinase 2 (LRRK2), a kinase involved in Parkinson's disease (PD). In health, PAK6 regulates neurite complexity in the brain and LRRK2 is required for its function, (a) whereas PAK6 is aberrantly activated in LRRK2-linked PD brain (b) suggesting that LRRK2 toxicity is mediated by PAK6. PMID:26375402

  16. Functional integrity of the t-tubular system in cardiomyocytes depends on p21-activated kinase 1

    PubMed Central

    DeSantiago, Jaime; Bare, Dan J; Ke, Yunbo; Sheehan, Katherine A.; Solaro, R. John; Banach, Kathrin

    2013-01-01

    p21-activated kinase (Pak1), a serine-threonine protein kinase, regulates cytoskeletal dynamics and cell motility. Recent experiments further demonstrate that loss of Pak1 results in exaggerated hypertrophic growth in response to pathophysiological stimuli. Calcium (Ca) signaling plays an important role in the regulation of transcription factors involved in hypertrophic remodeling. Here we aimed to determine the role of Pak1 in cardiac excitation-contraction coupling (ECC). Ca transients were recorded in isolated, ventricular myocytes (VMs) from WT and Pak1−/− mice. Pak1−/− Ca transients had a decreased amplitude, prolonged rise time and delayed recovery time. Di-8-ANNEPS staining revealed a decreased t-tubular density in Pak1−/− VMs that coincided with decreased cell capacitance and increased dis-synchrony of Ca induced Ca release (CICR) at individual release units. These changes were not observed in atrial myocytes of Pak1−/− mice where the t-tubular system is only sparsely developed. Experiments in cultured rabbit VMs supported a role of Pak1 in the maintenance of the t-tubular structure. T-tubular density in rabbit VMs significantly decreased within 24h of culture. This was accompanied by a decrease of the Ca transient amplitude and a prolongation of its rise time. However, overexpression of constitutively active Pak1 in VMs attenuated the structural remodeling as well as changes in ECC. The results provide significant support for a prominent role of Pak1 activity not only in the functional regulation of ECC but for the structural maintenance of the t-tubular system whose remodeling is an integral feature of hypertrophic remodeling. PMID:23612118

  17. LeftyA decreases Actin Polymerization and Stiffness in Human Endometrial Cancer Cells

    PubMed Central

    Salker, Madhuri S.; Schierbaum, Nicolas; Alowayed, Nour; Singh, Yogesh; Mack, Andreas F.; Stournaras, Christos; Schäffer, Tilman E.; Lang, Florian

    2016-01-01

    LeftyA, a cytokine regulating stemness and embryonic differentiation, down-regulates cell proliferation and migration. Cell proliferation and motility require actin reorganization, which is under control of ras-related C3 botulinum toxin substrate 1 (Rac1) and p21 protein-activated kinase 1 (PAK1). The present study explored whether LeftyA modifies actin cytoskeleton, shape and stiffness of Ishikawa cells, a well differentiated endometrial carcinoma cell line. The effect of LeftyA on globular over filamentous actin ratio was determined utilizing Western blotting and flow cytometry. Rac1 and PAK1 transcript levels were measured by qRT-PCR as well as active Rac1 and PAK1 by immunoblotting. Cell stiffness (quantified by the elastic modulus), cell surface area and cell volume were studied by atomic force microscopy (AFM). As a result, 2 hours treatment with LeftyA (25 ng/ml) significantly decreased Rac1 and PAK1 transcript levels and activity, depolymerized actin, and decreased cell stiffness, surface area and volume. The effect of LeftyA on actin polymerization was mimicked by pharmacological inhibition of Rac1 and PAK1. In the presence of the Rac1 or PAK1 inhibitor LeftyA did not lead to significant further actin depolymerization. In conclusion, LeftyA leads to disruption of Rac1 and Pak1 activity with subsequent actin depolymerization, cell softening and cell shrinkage. PMID:27404958

  18. A new role for cofilin in retinal neovascularization.

    PubMed

    Kumar, Raj; Janjanam, Jagadeesh; Singh, Nikhlesh K; Rao, Gadiparthi N

    2016-03-15

    Pak1 plays an important role in several cellular processes, including cell migration, but its role in pathological angiogenesis is not known. Here, we have determined its role in pathological retinal angiogenesis using an oxygen-induced retinopathy (OIR) model. VEGFA induced phosphorylation of Pak1 and its effector cofilin in a manner that was dependent on time as well as p38MAPKβ (also known as MAPK11) in human retinal microvascular endothelial cells (HRMVECs). Depletion of the levels of any of these molecules inhibited VEGFA-induced HRMVEC F-actin stress fiber formation, migration, proliferation, sprouting and tube formation. In accordance with these observations, hypoxia induced Pak1 and cofilin phosphorylation with p38MAPKβ being downstream to Pak1 and upstream to cofilin in mouse retina. Furthermore, Pak1 deficiency abolished hypoxia-induced p38MAPKβ and cofilin phosphorylation and abrogated retinal endothelial cell proliferation, tip cell formation and neovascularization. In addition, small interfering RNA (siRNA)-mediated downregulation of p38MAPKβ or cofilin levels in the wild-type mouse retina also diminished endothelial cell proliferation, tip cell formation and neovascularization. Taken together, these observations suggest that, although the p38MAPKβ-Pak1-cofilin axis is required for HRMVEC migration, proliferation, sprouting and tubulogenesis, Pak1-p38MAPKβ-cofilin signaling is also essential for hypoxia-induced mouse retinal endothelial cell proliferation, tip cell formation and neovascularization. PMID:26857814

  19. p21-activated kinase 1 restricts tonic endocannabinoid signaling in the hippocampus

    PubMed Central

    Xia, Shuting; Zhou, Zikai; Leung, Celeste; Zhu, Yuehua; Pan, Xingxiu; Qi, Junxia; Morena, Maria; Hill, Matthew N; Xie, Wei; Jia, Zhengping

    2016-01-01

    PAK1 inhibitors are known to markedly improve social and cognitive function in several animal models of brain disorders, including autism, but the underlying mechanisms remain elusive. We show here that disruption of PAK1 in mice suppresses inhibitory neurotransmission through an increase in tonic, but not phasic, secretion of endocannabinoids (eCB). Consistently, we found elevated levels of anandamide (AEA), but not 2-arachidonoylglycerol (2-AG) following PAK1 disruption. This increased tonic AEA signaling is mediated by reduced cyclooxygenase-2 (COX-2), and COX-2 inhibitors recapitulate the effect of PAK1 deletion on GABAergic transmission in a CB1 receptor-dependent manner. These results establish a novel signaling process whereby PAK1 upregulates COX-2, reduces AEA and restricts tonic eCB-mediated processes. Because PAK1 and eCB are both critically involved in many other organ systems in addition to the brain, our findings may provide a unified mechanism by which PAK1 regulates these systems and their dysfunctions including cancers, inflammations and allergies. DOI: http://dx.doi.org/10.7554/eLife.14653.001 PMID:27296803

  20. p21-activated kinase 1 restricts tonic endocannabinoid signaling in the hippocampus.

    PubMed

    Xia, Shuting; Zhou, Zikai; Leung, Celeste; Zhu, Yuehua; Pan, Xingxiu; Qi, Junxia; Morena, Maria; Hill, Matthew N; Xie, Wei; Jia, Zhengping

    2016-01-01

    PAK1 inhibitors are known to markedly improve social and cognitive function in several animal models of brain disorders, including autism, but the underlying mechanisms remain elusive. We show here that disruption of PAK1 in mice suppresses inhibitory neurotransmission through an increase in tonic, but not phasic, secretion of endocannabinoids (eCB). Consistently, we found elevated levels of anandamide (AEA), but not 2-arachidonoylglycerol (2-AG) following PAK1 disruption. This increased tonic AEA signaling is mediated by reduced cyclooxygenase-2 (COX-2), and COX-2 inhibitors recapitulate the effect of PAK1 deletion on GABAergic transmission in a CB1 receptor-dependent manner. These results establish a novel signaling process whereby PAK1 upregulates COX-2, reduces AEA and restricts tonic eCB-mediated processes. Because PAK1 and eCB are both critically involved in many other organ systems in addition to the brain, our findings may provide a unified mechanism by which PAK1 regulates these systems and their dysfunctions including cancers, inflammations and allergies. PMID:27296803

  1. The Cossidae (Lepidoptera) of Afghanistan with description of three new species and special notes on the fauna of Bande-Amir National Park.

    PubMed

    Yakovlev, Roman V; Pljustch, Igor G; Skrylnik, Yuriy; Pak, Oleg; Witt, Thomas J

    2015-01-01

    The annotated list of Cossidae of Afghanistan consists of 44 species in 17 genera from the four subfamilies Catoptinae, Cossinae, Zeuzerinae, and Mehariinae. Three new species are described: Cossulus habibae Yakovlev, Pljustch, Skrylnik & Pak, sp. nov., Semagystia bamiani Yakovlev, Pljustch, Skrylnik & Pak, sp. nov., Phragmacossia bandeamiri Yakovlev, Pljustch, Skrylnik & Pak, sp. nov.; all from Band-e-Amir National Park in Bamian Province. Three species (Dervishiya cadambae (Moore, 1865), Semagystia cossoides (Graeser, 1892), Phragmacossia territa (Staudinger, 1879)) are reported for the first time from Afghanistan. A brief biogeographical analysis of the Cossidae of Afghanistan is given. PMID:26250219

  2. Human immunodeficiency virus type 1 Nef associates with a member of the p21-activated kinase family.

    PubMed Central

    Nunn, M F; Marsh, J W

    1996-01-01

    Although human immunodeficiency virus (HIV) Nef is essential for the induction of AIDS, its biochemical function has remained an enigma. In this study, HIV Nef protein is shown to associate with a serine-threonine kinase that recognizes histone H4 as a substrate, is serologically related to rat p21-activated kinase (PAK), and is specifically activated by Rac and Cdc42. These characteristics define the Nef-associated kinase as belonging to the PAK family. PAKs initiate kinase cascades in response to environmental stimuli, and their identification as a target of Nef implicates these signaling molecules in HIV pathogenesis and provides a novel target for clinical intervention. PMID:8709241

  3. Further Adventures of Dr. Sony's Mad Monster Machine, or Cutting the Studio Umbilical Cord

    ERIC Educational Resources Information Center

    Steffin, Sherwin

    1977-01-01

    We must reexamine our often total reliance on the studio as the only source for instructional television production. The porta-pak provides an alternative. Tips are provided for successful field production. (Author/STS)

  4. Down-regulated expression of miR-134 contributes to paclitaxel resistance in human ovarian cancer cells.

    PubMed

    Shuang, Ting; Wang, Min; Shi, Cong; Zhou, Yingying; Wang, Dandan

    2015-10-01

    MiR-134 has been reported to have a role in the development and progression of various cancers. In this study, we found that miR-134 expression was significantly decreased in chemo-resistant serous epithelial ovarian cancer (EOC) patients. Over-expression of miR-134 enhanced the sensitivity of SKOV3-TR30 cells to paclitaxel, and increased paclitaxel-induced apoptosis. Further, Pak2 was identified as a direct target of miR-134, and Pak2-specific siRNA increased cell inhibition rate and promoted paclitaxal-induced apoptosis. By regulating Pak2 expression, miR-134 could mediate Bad phosphorylation at Ser112 and Ser136, which affected cell survival and apoptosis. In conclusion, our findings indicate that repression of miR-134 and consequent up-regulation of Pak2 might contribute to paclitaxel resistance. PMID:26363097

  5. Precision Nanoparticles

    ScienceCinema

    John Hemminger

    2010-01-08

    A revolutionary technology that efficiently produces nanoparticles in uniform and prescribed sizes (1-100 nanometers) using supercritical fluids. INL researcher Robert Fox was joined by Idaho State University researchers Rene Rodriquez and Joshua Pak in d

  6. Light exposure before learning improves memory consolidation at night.

    PubMed

    Shan, Li-Li; Guo, Hao; Song, Ning-Ning; Jia, Zheng-Ping; Hu, Xin-Tian; Huang, Jing-Fei; Ding, Yu-Qiang; Richter-Levin, Gal; Richter-Levine, Gal; Zhou, Qi-Xin; Xu, Lin

    2015-01-01

    Light is recently recognized as a modulator able to activate the hippocampus and modulate memory processing, but little is known about the molecular mechanisms. Here, we report that in mice, a short pulse of white light before learning dramatically improves consolidation of contextual fear memory during the night. The light exposure increases hippocampal active p21-activated kinase 1 (PAK1) and CA1 long-term potentiation (LTP). These light effects are abolished in PAK1 knockout and dominant-negative transgenic mice, but preserved by expression of constitutively active PAK1 in the hippocampus. Our results indicate that light can act as a switch of PAK1 activity that modulate CA1 LTP and thereby memory consolidation without affecting learning and short-term memory. PMID:26493375

  7. Ombitasvir, Paritaprevir, Ritonavir, and Dasabuvir

    MedlinePlus

    Viekira Pak® (as a combination product containing Ombitasvir, Paritaprevir, Ritonavir, Dasabuvir) ... C infection (swelling of the liver caused by a virus). Ombitasvir is a hepatitis C virus (HCV) ...

  8. Precision Nanoparticles

    SciTech Connect

    John Hemminger

    2009-07-21

    A revolutionary technology that efficiently produces nanoparticles in uniform and prescribed sizes (1-100 nanometers) using supercritical fluids. INL researcher Robert Fox was joined by Idaho State University researchers Rene Rodriquez and Joshua Pak in d

  9. Light exposure before learning improves memory consolidation at night

    PubMed Central

    Shan, Li-Li; Guo, Hao; Song, Ning-Ning; Jia, Zheng-Ping; Hu, Xin-Tian; Huang, Jing-Fei; Ding, Yu-Qiang; Richter-Levine, Gal; Zhou, Qi-Xin; Xu, Lin

    2015-01-01

    Light is recently recognized as a modulator able to activate the hippocampus and modulate memory processing, but little is known about the molecular mechanisms. Here, we report that in mice, a short pulse of white light before learning dramatically improves consolidation of contextual fear memory during the night. The light exposure increases hippocampal active p21-activated kinase 1 (PAK1) and CA1 long-term potentiation (LTP). These light effects are abolished in PAK1 knockout and dominant-negative transgenic mice, but preserved by expression of constitutively active PAK1 in the hippocampus. Our results indicate that light can act as a switch of PAK1 activity that modulate CA1 LTP and thereby memory consolidation without affecting learning and short-term memory. PMID:26493375

  10. 75 FR 52385 - Office of Hazardous Materials Safety; Actions on Special Permit Applications

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-08-25

    ... were issued. Issued in Washington, DC, on August 18, 2010. Donald Burger, Chief, Special Permits and... add several new fuel tanks to the special permit. 14656-M......... PurePak 49 CFR 173.158 To...