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Sample records for inhibitor protects mesothelial

  1. A Nanoconjugate Apaf-1 Inhibitor Protects Mesothelial Cells from Cytokine-Induced Injury

    PubMed Central

    Santamaría, Beatriz; Benito-Martin, Alberto; Ucero, Alvaro Conrado; Aroeira, Luiz Stark; Reyero, Ana; Vicent, María Jesús; Orzáez, Mar; Celdrán, Angel; Esteban, Jaime; Selgas, Rafael; Ruíz-Ortega, Marta; Cabrera, Manuel López; Egido, Jesús; Pérez-Payá, Enrique; Ortiz, Alberto

    2009-01-01

    Background Inflammation may lead to tissue injury. We have studied the modulation of inflammatory milieu-induced tissue injury, as exemplified by the mesothelium. Peritoneal dialysis is complicated by peritonitis episodes that cause loss of mesothelium. Proinflammatory cytokines are increased in the peritoneal cavity during peritonitis episodes. However there is scarce information on the modulation of cell death by combinations of cytokines and on the therapeutic targets to prevent desmesothelization. Methodology Human mesothelial cells were cultured from effluents of stable peritoneal dialysis patients and from omentum of non-dialysis patients. Mesothelial cell death was studied in mice with S. aureus peritonitis and in mice injected with tumor necrosis factor alpha and interferon gamma. Tumor necrosis factor alpha and interferon gamma alone do not induce apoptosis in cultured mesothelial cells. By contrast, the cytokine combination increased the rate of apoptosis 2 to 3-fold over control. Cell death was associated with the activation of caspases and a pancaspase inhibitor prevented apoptosis. Specific caspase-8 and caspase-3 inhibitors were similarly effective. Co-incubation with both cytokines also impaired mesothelial wound healing in an in vitro model. However, inhibition of caspases did not improve wound healing and even impaired the long-term recovery from injury. By contrast, a polymeric nanoconjugate Apaf-1 inhibitor protected from apoptosis and allowed wound healing and long-term recovery. The Apaf-1 inhibitor also protected mesothelial cells from inflammation-induced injury in vivo in mice. Conclusion Cooperation between tumor necrosis factor alpha and interferon gamma contributes to mesothelial injury and impairs the regenerative capacity of the monolayer. Caspase inhibition attenuates mesothelial cell apoptosis but does not facilitate regeneration. A drug targeting Apaf-1 allows protection from apoptosis as well as regeneration in the course of

  2. Plasminogen Activator Inhibitor-1 Deficiency Augments Visceral Mesothelial Organization, Intrapleural Coagulation, and Lung Restriction in Mice with Carbon Black/Bleomycin–Induced Pleural Injury

    PubMed Central

    Jeffers, Ann; Alvarez, Alexia; Owens, Shuzi; Koenig, Kathleen; Quaid, Brandon; Komissarov, Andrey A.; Florova, Galina; Kothari, Hema; Pendurthi, Usha; Mohan Rao, L. Vijaya; Idell, Steven

    2014-01-01

    Local derangements of fibrin turnover and plasminogen activator inhibitor (PAI)-1 have been implicated in the pathogenesis of pleural injury. However, their role in the control of pleural organization has been unclear. We found that a C57Bl/6j mouse model of carbon black/bleomycin (CBB) injury demonstrates pleural organization resulting in pleural rind formation (14 d). In transgenic mice overexpressing human PAI-1, intrapleural fibrin deposition was increased, but visceral pleural thickness, lung volumes, and compliance were comparable to wild type. CBB injury in PAI-1−/− mice significantly increased visceral pleural thickness (P < 0.001), elastance (P < 0.05), and total lung resistance (P < 0.05), while decreasing lung compliance (P < 0.01) and lung volumes (P < 0.05). Collagen, α-smooth muscle actin, and tissue factor were increased in the thickened visceral pleura of PAI-1−/− mice. Colocalization of α-smooth muscle actin and calretinin within pleural mesothelial cells was increased in CBB-injured PAI-1−/− mice. Thrombin, factor Xa, plasmin, and urokinase induced mesothelial–mesenchymal transition, tissue factor expression, and activity in primary human pleural mesothelial cells. In PAI-1−/− mice, D-dimer and thrombin–antithrombin complex concentrations were increased in pleural lavage fluids. The results demonstrate that PAI-1 regulates CBB-induced pleural injury severity via unrestricted fibrinolysis and cross-talk with coagulation proteases. Whereas overexpression of PAI-1 augments intrapleural fibrin deposition, PAI-1 deficiency promotes profibrogenic alterations of the mesothelium that exacerbate pleural organization and lung restriction. PMID:24024554

  3. Mesothelial cell transplantation.

    PubMed

    Witkowicz, Joanna

    2008-05-01

    Mesothelial cells are an integral part of the peritoneum and play an important role in maintaining its structural and functional properties. In the recent years a number of studies on mesothelial cells have been performed to evaluate the localization, secretional properties and the ability of regeneration and transdifferentiation of these cells. They are also involved in the repair of the peritoneum damage following surgery or peritonitis. Mesothelial cells produce several cytokines, growth factors and extracellular matrix components, possessing anti-inflammatory and immunomodulatory properties. Because of their plasticity, these cells are able to form a new cell type like fibroblast, endothelial and smooth muscle cell, chondrocyte, osteoblast, adipocyte or neuron. The first step involves mesothelial cell transdifferentiation into progenitor cells with the capacity of further differentiation. In this paper the current knowledge concerning the mesothelial cell differentiation and transplantation has been reviewed. Own mesothelial cells of a patient are used in transplantation. They are sampled, cultured in vitro and then they can be used in the prevention and treatment of post-operative abdominal adhesions, incisional hernias, repair of peritoneal membrane of patients on long-term peritoneal dialysis, the prevention of ischemic myocardial damage, nerve regeneration and genetically modified recombinant protein secretion. Inevitably, more potential applications of transplanted mesothelial cell will be available over the next few years.

  4. Immunohistochemical detection of XIAP in mesothelium and mesothelial lesions.

    PubMed

    Wu, Maoxin; Sun, Yuhua; Li, Gan; Desman, Garrett; Wang, Beverly; Gil, Joan; Burstein, David E

    2007-11-01

    We examined benign and malignant mesothelial tissue samples for the presence of X-linked inhibitor of apoptosis protein (XIAP), a potent constituent of the inhibitor of apoptosis family of caspase inhibitors. We subjected 55 sections (31 malignant mesotheliomas, 2 well-differentiated peritoneal mesotheliomas, 13 pleural mesothelial hyperplasias, and 9 benign mesothelial tissues) from archival formalin-fixed, paraffin-embedded surgical tissue blocks to citrate-based antigen retrieval and then incubated them with monoclonal anti-XIAP (clone 48, dilution 1:250; BD Biosciences, San Jose, CA) at 4 degrees C for 72 hours and developed them using EnVision-Plus reagents (DAKO, Carpinteria, CA) and diaminobenzidine as the chromogen. Particulate or nonhomogeneous cytoplasmic staining was considered positive. All 9 normal mesothelial samples were negative for XIAP. Of 13 mesothelial hyperplasias, 1 (8%) was weakly positive in fewer than 10% of cells, as was 1 of 2 well-differentiated peritoneal mesotheliomas. Of 31 malignant mesotheliomas, 25 (81%) displayed XIAP positivity. XIAP immunostaining, when strong, allows for distinction of malignant from benign and hyperplastic mesothelial cell populations and is a potentially useful immunodiagnostic marker in small samples and morphologically controversial cases. Elevated expression of XIAP could contribute to tumorigenesis in mesothelioma.

  5. Migrating corrosion inhibitor protection of concrete

    SciTech Connect

    Bjegovic, D.; Miksic, B.

    1999-11-01

    Migrating corrosion inhibitors (MCI) were developed to protect steel rebar from corrosion in concrete. They were designed to be incorporated as an admixture during concrete batching or used for surface impregnation of existing concrete structures. Two investigations are summarized. One studied the effectiveness of MCIs as a corrosion inhibitor for steel rebar when used as an admixture in fresh concrete mix. The other is a long-term study of MCI concrete impregnation that chronicles corrosion rates of rebar in concrete specimens. Based on data from each study, it was concluded that migrating corrosion inhibitors are compatible with concrete and effectively delay the onset of corrosion.

  6. Corrosion protection with eco-friendly inhibitors

    NASA Astrophysics Data System (ADS)

    Shahid, Muhammad

    2011-12-01

    Corrosion occurs as a result of the interaction of a metal with its environment. The extent of corrosion depends on the type of metal, the existing conditions in the environment and the type of aggressive ions present in the medium. For example, CO3-2 and NO-3 produce an insoluble deposit on the surface of iron, resulting in the isolation of metal and consequent decrease of corrosion. On the other hand, halide ions are adsorbed selectively on the metal surface and prevent formation of the oxide phase on the metal surface, resulting in continuous corrosion. Iron, aluminum and their alloys are widely used, both domestically and industrially. Linear alkylbenzene and linear alkylbenzene sulfonate are commonly used as detergents. They have also been found together in waste water. It is claimed that these chemicals act as inhibitors for stainless steel and aluminum. Release of toxic gases as a result of corrosion in pipelines may lead in certain cases to air pollution and possible health hazards. Therefore, there are two ways to look at the relationship between corrosion and pollution: (i) corrosion of metals and alloys due to environmental pollution and (ii) environmental pollution as a result of corrosion protection. This paper encompasses the two scenarios and possible remedies for various cases, using 'green' inhibitors obtained either from plant extracts or from pharmaceutical compounds. In the present study, the effect of piperacillin sodium as a corrosion inhibitor for mild steel was investigated using a weight-loss method as well as a three-electrode dc electrochemical technique. It was found that the corrosion rate decreased as the concentration of the inhibitor increased up to 9×10-4 M 93% efficiency was exhibited at this concentration.

  7. Evaluation of Encapsulated Inhibitor for Autonomous Corrosion Protection

    NASA Technical Reports Server (NTRS)

    Johnsey, M. N.; Li, W.; Buhrow, J. W.; Calle, L. M.; Pearman, B. P.; Zhang, X.

    2015-01-01

    This work concerns the development of smart coating technologies based on microencapsulation for the autonomous control of corrosion. Microencapsulation allows the incorporation of corrosion inhibitors into coating which provides protection through corrosion-controlled release of these inhibitors.One critical aspect of a corrosion protective smart coating is the selection of corrosion inhibitor for encapsulation and comparison of the inhibitor function before and after encapsulation. For this purpose, a systematic approach is being used to evaluate free and encapsulated corrosion inhibitors by salt immersion. Visual, optical microscope, and Scanning Electron Microscope (with low-angle backscatter electron detector) are used to evaluate these inhibitors. It has been found that the combination of different characterization tools provide an effective method for evaluation of early stage localized corrosion and the effectiveness of corrosion inhibitors.

  8. Electrolyte and Fluid Transport in Mesothelial Cells

    PubMed Central

    Ji, Hong-Long; Nie, Hong-Guang

    2008-01-01

    Mesothelial cells are specialized epithelial cells, which line the pleural, pericardial, and peritoneal cavities. Accumulating evidence suggests that the monolayer of mesothelial cells is permeable to electrolyte and fluid, and thereby govern both fluid secretion and re-absorption in the serosal cavities. Disorders in these salt and fluid transport systems may be fundamental in the pathogenesis of pleural effusion, pericardial effusion, and ascites. In this review, we discuss the location, physiological function, and regulation of active transport (Na+-K+-ATPase) systems, cation and anion channels (Na+, K+, Cl−, and Ca2+ channels), antiport (exchangers) systems, and symport (co-transporters) systems, and water channels (aquaporins). These secretive and absorptive pathways across mesothelial monolayer cells for electrolytes and fluid may provide pivotal therapeutical targets for novel clinical intervention in edematous diseases of serous cavities. PMID:19169368

  9. Actin polymerization plays a significant role in asbestos-induced inflammasome activation in mesothelial cells in vitro.

    PubMed

    MacPherson, Maximilian; Westbom, Catherine; Kogan, Helen; Shukla, Arti

    2016-12-24

    Asbestos exposure leads to malignant mesothelioma (MM), a deadly neoplasm of mesothelial cells of various locations. Although there is no doubt about the role of asbestos in MM tumorigenesis, mechanisms are still not well explored. Recently, our group demonstrated that asbestos causes inflammasome priming and activation in mesothelial cells, which in part is dependent on oxidative stress. Our current study sheds light on yet another mechanism of inflammasome activation by asbestos. Here we show the role of actin polymerization in asbestos-induced activation of the nod-like receptor pyrin domain-containing protein 3 (NLRP3) inflammasome. Using human mesothelial cells, we first demonstrate that asbestos and carbon nanotubes induced caspase-1 activation and high-mobility group box 1, interleukin 1 beta and interleukin 18 secretion was blocked by Cytochalasin D (Cyto D) an actin polymerization inhibitor. Next, to understand the mechanism, we assessed whether phagocytosis of fibers by mesothelial cells is affected by actin polymerization inhibition. Transmission electron microscopy showed the inhibition of fiber uptake by mesothelial cells in the presence of Cyto D. Furthermore, localization of components of the inflammasome, apoptotic speck-like protein containing a CARD domain (ASC) and NLRP3, to the perinuclear space in mitochondria or endoplasmic reticulum in response to fiber exposure was also interrupted in the presence of Cyto D. Taken together, our studies suggest that actin polymerization plays important roles in inflammasome activation by fibers via regulation of phagocytosis and/or spatial localization of inflammasome components.

  10. Mesothelial inclusion cyst: a rare occurrence

    PubMed Central

    Soon, David SC; Shilton, Hamish; Andrabi, Ali

    2016-01-01

    Mesothelial inclusion cyst is a rare benign tumour that has only 130 cases reported in the literature. Accurate diagnosis and optimal management of this condition remains uncertain. We report a 51-year-old African gentleman, whom presents with abdominal pain and constipation. A computed tomography scan was performed and revealed a large cystic lesion in the right paracolic gutter. The differential diagnosis included appendiceal mucinous neoplasm, cystic tuberculosis and duplication cyst. A laparotomy was performed due to his symptoms and size of the cyst. Macroscopically, the tumour had a size of 25 × 10 × 10 cm and revealed a necrotic lymph node. It was resected en bloc with the appendix and an ileocolic anastomosis performed. Histology revealed a diagnosis of mesothelial inclusion cyst and acute appendicitis. The patient recovered well and had no recurrence at 2-year follow-up. PMID:27994008

  11. Protection from latent inhibition provided by a conditioned inhibitor.

    PubMed

    McConnell, Bridget L; Wheeler, Daniel S; Urcelay, Gonzalo P; Miller, Ralph R

    2009-10-01

    Two conditioned suppression experiments with rats investigated the influence on latent inhibition of compounding a Pavlovian conditioned inhibitor with the target cue during preexposure treatment. Results were compared with those of subjects that received conventional latent inhibition training, no preexposure, or preexposure to the target cue in compound with a neutral stimulus. In Experiment 1, greater attenuation of the latent inhibition effect was observed in subjects that received target preexposure in compound with a Pavlovian conditioned inhibitor relative to subjects that received preexposure with a neutral stimulus or to the target alone. In Experiment 2, this protection from latent inhibition was attenuated if the excitor that was used to train the conditioned inhibitor was extinguished between preexposure and target training. The results are consistent with an account offered by the extended comparator hypothesis.

  12. Protection from noise-induced hearing loss with Src inhibitors.

    PubMed

    Bielefeld, Eric C

    2015-06-01

    Noise-induced hearing loss is a major cause of acquired hearing loss around the world and pharmacological approaches to protecting the ear from noise are under investigation. Noise results in a combination of mechanical and metabolic damage pathways in the cochlea. The Src family of protein tyrosine kinases could be active in both pathways and Src inhibitors have successfully prevented noise-induced cochlear damage and hearing loss in animal models. The long-term goal is to optimize delivery methods into the cochlea to reduce invasiveness and limit side-effects before human clinical testing can be considered. At their current early stage of research investigation, Src inhibitors represent an exciting class of compounds for inclusion in a multifaceted pharmacological approach to protecting the ear from noise.

  13. Asbestos-associated chromosomal changes in human mesothelial cells

    SciTech Connect

    Lechner, J.F.; Tokiwa, T.; LaVeck, M.; Benedict, W.F.; Banks-Schlegel, S.; Yeager, H. Jr.; Banerjee, A.; Harris, C.C.

    1985-06-01

    Replicative cultures of human pleural mesothelial cells were established from noncancerous adult donors. The cells exhibited normal mesothelial cell characteristics including keratin, hyaluronic acid mucin, and long branched microvilli, and they retained the normal human karyotype until senescence. The mesothelial cells were 10 and 100 times more sensitive to the cytotoxic effects of asbestos fibers than normal human bronchial epithelial or fibroblastic cells, respectively. In addition, cultures of mesothelial cells that survived two cytotoxic exposures of amosite fibers were aneuploid with consistent specific chromosomal losses indicative of clonal origin. These aneuploid cells exhibit both altered growth control properties and a population doubling potential of >50 divisions beyond the culture life span (30 doublings) of the control cells.

  14. Inhibitors, cladded trees protect sour gas wells in Abu Dhabi

    SciTech Connect

    Morsi, K.M. )

    1994-06-13

    Continuous chemical inhibition has prevented corrosion downhole, and tests indicate that Inconel 625 cladding will protect the christmas trees on wells producing sour gas from the Thamama C reservoir. Metallic corrosion is a costly problem. Estimates indicate that corrosion costs the oil industry several billion dollars per year. In addition, oil companies spend over $100 million/year on corrosion inhibitors for combating downhole tubular and casing corrosion. Abu Dhabi National Oil Co. (Adnoc) has successfully completed wells in extremely harsh operating conditions with high temperatures, pressures, and high concentrations of H[sub 2]S, CO[sub 2], and brine. Such environments require special materials for downhole and surface equipment. The Thamama C reservoir, in an onshore gas field, produces gas containing H[sub 2]S and CO[sub 2] in the range of 0.7--8.0 mole % and 4.0--8.0 mole %, respectively. The Thamama C gas-gathering system comprises 19 wells connected to four trunk lines that transport produced gas and associated condensate to a central processing plant. The paper discusses material and inhibitor selection.

  15. Periaortic lymph node involvement by metastatic angiosarcoma and benign sinus mesothelial cells.

    PubMed

    Isotalo, P A; Jabit, M; Wenckebach, G F

    2001-05-01

    Hyperplastic mesothelial cells involving lymph node sinuses have only been recently described. Most nodal mesothelial cells are thought to originate from mesothelial surfaces disrupted by serosal effusions. Dislodged mesothelial cells likely gain access to submesothelial lymphatics via mesothelial stomata and disseminate to draining lymph nodes. Unusual lymph node architectural patterns result when benign sinus mesothelial cells occur concurrently with a neoplastic nodal process. We describe a young man who developed diffuse metastases from a primary cardiac angiosarcoma. His periaortic lymph nodes contained metastatic angiosarcoma and hyperplastic mesothelial cells with a sinus distribution. The patient had a clinical history of progressive haemoperitoneum, exacerbated by thrombocytopaenia and disseminated intravascular coagulation. Massive haemoperitoneum of 5000 ml was confirmed at autopsy. This is the first report to suggest that multiple episodes of intraperitoneal haemorrhage and ascites may both act in the same manner to cause dislodgment and dissemination of mesothelial cells to draining lymph node sinuses.

  16. The DPP4 Inhibitor Linagliptin Protects from Experimental Diabetic Retinopathy

    PubMed Central

    Dietrich, Nadine; Kolibabka, Matthias; Busch, Stephanie; Bugert, Petra; Kaiser, Ulrike; Lin, Jihong; Fleming, Thomas; Morcos, Michael; Klein, Thomas; Schlotterer, Andrea; Hammes, Hans-Peter

    2016-01-01

    Background/aims Dipeptidyl peptidase 4 (DPP4) inhibitors improve glycemic control in type 2 diabetes, however, their influence on the retinal neurovascular unit remains unclear. Methods Vasculo- and neuroprotective effects were assessed in experimental diabetic retinopathy and high glucose-cultivated C. elegans, respectively. In STZ-diabetic Wistar rats (diabetes duration of 24 weeks), DPP4 activity (fluorometric assay), GLP-1 (ELISA), methylglyoxal (LC-MS/MS), acellular capillaries and pericytes (quantitative retinal morphometry), SDF-1a and heme oxygenase-1 (ELISA), HMGB-1, Iba1 and Thy1.1 (immunohistochemistry), nuclei in the ganglion cell layer, GFAP (western blot), and IL-1beta, Icam1, Cxcr4, catalase and beta-actin (quantitative RT-PCR) were determined. In C. elegans, neuronal function was determined using worm tracking software. Results Linagliptin decreased DPP4 activity by 77% and resulted in an 11.5-fold increase in active GLP-1. Blood glucose and HbA1c were reduced by 13% and 14% and retinal methylglyoxal by 66%. The increase in acellular capillaries was diminished by 70% and linagliptin prevented the loss of pericytes and retinal ganglion cells. The rise in Iba-1 positive microglia was reduced by 73% with linagliptin. In addition, the increase in retinal Il1b expression was decreased by 65%. As a functional correlate, impairment of motility (body bending frequency) was significantly prevented in C. elegans. Conclusion Our data suggest that linagliptin has a protective effect on the microvasculature of the diabetic retina, most likely due to a combination of neuroprotective and antioxidative effects of linagliptin on the neurovascular unit. PMID:27942008

  17. Mutant p53 promotes ovarian cancer cell adhesion to mesothelial cells via integrin β4 and Akt signals.

    PubMed

    Lee, Jong-Gyu; Ahn, Ji-Hye; Jin Kim, Tae; Ho Lee, Jae; Choi, Jung-Hye

    2015-07-30

    Missense mutations in the TP53 gene resulting in the accumulation of mutant proteins are extremely common in advanced ovarian cancer, which is characterised by peritoneal metastasis. Attachment of cancer cells to the peritoneal mesothelium is regarded as an initial, key step for the metastatic spread of ovarian cancer. In the present study, we investigated the possible role of a p53 mutant in the mesothelial adhesion of ovarian cancer cells. We found that OVCAR-3 cells with the R248 TP53 mutation (p53(R248)) were more adhesive to mesothelial Met5A cells than were A2780 cells expressing wild-type p53. In addition, ectopic expression of p53(R248) in p53-null SKOV-3 cells significantly increased adhesion to Met5A cells. Knockdown of mutant p53 significantly compromised p53(R248)-induced cell adhesion to Met5A cells. Microarray analysis revealed that several adhesion-related genes, including integrin β4, were markedly up-regulated, and certain signalling pathways, including PI3K/Akt, were activated in p53(R248) transfectants of SKOV-3 cells. Inhibition of integrin β4 and Akt signalling using blocking antibody and the inhibitor LY294002, respectively, significantly attenuated p53(R248)-mediated ovarian cancer-mesothelial adhesion. These data suggest that the p53(R248) mutant endows ovarian cancer cells with increased adhesiveness and that integrin β4 and Akt signalling are associated with the mutation-enhanced ovarian cancer-mesothelial cell adhesion.

  18. Mesothelial cell autoantibodies upregulate transcription factors associated with fibrosis.

    PubMed

    Gilmer, John; Harding, Tanner; Woods, Linda; Black, Brad; Flores, Raja; Pfau, Jean

    2017-01-01

    Amphibole asbestos exposure is associated with the production of mesothelial cell autoantibodies (MCAA). These MCAA have been linked with pleural fibrotic disease in the asbestos exposed community of Libby, Montana, and induce collagen deposition by cultured mesothelial cells. However, the exact intracellular mechanism by which these autoantibodies cause an increase in collagen deposition remains unknown. This study sought to gain insight into the transcription factors involved in the collagen production after human mesothelial cells are exposed to MCAA. In this study, transcription factor activation profiles were generated from human mesothelial cells (Met5A) treated with serum from Libby subjects, and were compared to cells treated with serum cleared of IgG, and therefore containing no MCAA. Analysis of those profiles indicated C/EBP-beta and hypoxia inducible factor 1 alpha (HIF-1α) are significantly increased in the nucleus, indicating activation, due to MCAA exposure compared to controls. Inhibition of either of these transcription factors significantly reduced collagen 1 deposition by these cells following exposure to MCAA. These data suggest autoantibodies are directly involved in type I collagen deposition and may elucidate potential therapeutic targets for autoantibody mediated fibrosis.

  19. Protection of bronze artefacts through polymeric coatings based on nanocarriers filled with corrosion inhibitors

    NASA Astrophysics Data System (ADS)

    de Luna, Martina Salzano; Buonocore, Giovanna; Di Carlo, Gabriella; Giuliani, Chiara; Ingo, Gabriel M.; Lavorgna, Marino

    2016-05-01

    Protective coatings based on polymers synthesized from renewable sources (chitosan or an amorphous vinyl alcohol based polymer) have been prepared for the protection of bronze artifacts from corrosion. Besides acting as an effective barrier against corrosive species present in the environment, the efficiency of the coatings has been improved by adding corrosion inhibitor compounds (benzotriazole or mercaptobenzothiazole) to the formulations. The liquid medium of the formulations has been carefully selected looking at maximizing the wettability on the bronze substrate and optimizing the solvent evaporation rate. The minimum amount of inhibitor compounds has been optimized by performing accelerated corrosion tests on coated bronze substrates. The inhibitors have been directly dissolved in the coating-forming solutions and/or introduced by means of nanocarriers, which allow to control the release kinetics. The free dissolved inhibitor molecules immediately provide a sufficient protection against corrosion. On the other hand, the inhibitor molecules contained in the nanocarriers serve as long-term reservoir, which can be activated by external corrosion-related stimuli in case of particularly severe conditions. Particular attention has been paid to other features which affect the coating performances. Specifically, the adhesion of the protective polymer layer to the bronze substrate has been assessed, as well as its permeability properties and transparency, the latter being a fundamental feature of protective coating for cultural heritages. Finally, the protective efficiency of the produced smart coatings has been assessed through accelerated corrosion tests.

  20. Simple mesothelial pericardial cyst in a rare location.

    PubMed

    Ranchordás, Sara; Gomes, Catarina; Abecasis, Miguel; Gouveia, Rosa; Abecasis, João; Lopes, Luís R; Fazendas, Paula

    2016-09-01

    Pericardial cysts are rare and generally benign intrathoracic lesions, most frequently located in the cardiophrenic angles, but other locations have been described. We present a case of a pericardial cyst in a previously undescribed site. Our patient presented with a cyst in the interventricular septum which was discovered as an incidental finding. After surgical excision of the cyst, it was described pathologically as a simple mesothelial pericardial cyst. The explanation of this rare condition is uncertain, but some hypotheses can be outlined.

  1. Transient protective effect of caspase inhibitors in RCS rat.

    PubMed

    Perche, O; Doly, M; Ranchon-Cole, I

    2008-03-01

    In most retinal degenerations in humans and in animal models, photoreceptor cells die by apoptosis. Although the biochemical features are similar in all apoptotic cells, different molecular events lead the cell to death. In the present study we used a rat model of inherited retinal degeneration, the RCS rats, to investigate the involvement of the proteases, caspases and/or calpains, in photoreceptor apoptosis. In the first experiments, rats were untreated or injected intravitreally at post natal day 27 (P27) with the large broad spectrum caspase inhibitor, ZVAD, the calpain inhibitor, MuhPhe, or with the vehicle, DMSO. Retinal status was evaluated at P35 and P42 by electroretinography, morphometry and apoptotic nuclei detection. DMSO and MuhPhe had no effect on RCS retinas as evidenced by equivalent loss of function and equivalent number of apoptotic cells than in untreated group. ZVAD transiently reduced apoptotic cells and preserved photoreceptor function at P35 but not at P42. These results suggest that caspases but not calpains are involved in retinal degeneration in the RCS. In the second experiments, RCS rats were injected twice at P27 and P35 with ZVAD or DMSO. Although ZVAD-treated retinas were preserved at P35 compared to the DMSO controls, the second injection of ZVAD did not extend the preserving effect to P42. Moreover, a single injection of ZVAD at P35 had no preserving effect at P42. All these data taken together suggest that caspases do not play a pivotal role after P35. In a fourth set of experiments, we used specific caspase inhibitors to elucidate which caspase was activated. The caspase-1/4 inhibitor (YVAD) or the caspase-3/7 inhibitor (DEVD) were injected intravitreally at P27 and retinal status was evaluated at P35 and P42. Electroretinograms and apoptotic nuclei detection demonstrated that YVAD and DEVD preserved photoreceptors at P35 but not at P42. These results suggest that both caspase-1/4 and caspase-3/7 play a major role in the apoptotic

  2. Inhibition of NF-kappaB with Dehydroxymethylepoxyquinomicin modifies the function of human peritoneal mesothelial cells

    PubMed Central

    Sosińska, Patrycja; Baum, Ewa; Maćkowiak, Beata; Staniszewski, Ryszard; Jasinski, Tomasz; Umezawa, Kazuo; Bręborowicz, Andrzej

    2016-01-01

    Peritoneal mesothelial cells exposed to bioincompatible dialysis fluids contribute to damage of the peritoneum during chronic dialysis. Inflammatory response triggered in the mesothelium leading to neovascularization and fibrosis plays an important role in that process. We studied the effects of Dehydroxymethyepoxyquinmicin (DHMEQ)-an NF-κB inhibitor on function of human peritoneal mesothelial cells (HPMC) in in vitro culture. DHMEQ studied in concentrations of 1-10 µg/ml was not toxic to HPMC. Synthesis of IL-6, MCP-1 and hyaluronan in unstimulated and stimulated with interleukin-1 (100 pg/ml) HPMC was inhibited in the presence of DHMEQ and the effect was proportional to the dose of the drug. DHMEQ (10 µg/ml) reduced in unstimulated HPMC synthesis of IL-6 (-55%), MCP-1 (-58%) and hyaluronan (-41%). Respective values for stimulated HMPC were: -63% for IL-6, -57% for MCP-1 and -67% for hyaluronan. The observed effects were due to the suppression of the expression of genes responsible for the synthesis of these molecules. DHMEQ modified the effects of the effluent dialysates from CAPD patients on the function of HMPC. Dialysate induced accelerated growth of these cells, and synthesis of collagen was inhibited in the presence of DHMEQ 10 µg/ml, by 69% and 40%, respectively. The results of our study show that DHMEQ effectively reduces inflammatory response in HMPC and prevents excessive dialysate induced proliferation and collagen synthesis in these cells. All of these effects may be beneficial during chronic peritoneal dialysis and prevents progressive dialysis-induced damage to the peritoneum. PMID:28078047

  3. Do proton pump inhibitors protect against cancer progression in GERD?

    PubMed

    Miyashita, Tomoharu; Shah, Furhawn A; Harmon, John W; Marti, Guy P; Matsui, Daisuke; Okamoto, Koichi; Makino, Isamu; Hayashi, Hironori; Oyama, Katsunobu; Nakagawara, Hisatoshi; Tajima, Hidehiro; Fujita, Hideto; Takamura, Hiroyuki; Murakami, Manabu; Ninomiya, Itasu; Kitagawa, Hirohisa; Fushida, Sachio; Fujimura, Takashi; Ohta, Tetsuo

    2013-08-01

    Gastro-duodenal content reflux from gastro-esophageal reflux disease (GERD) induces the inflammation-metaplasia-dysplasia-adenocarcinoma sequence. Proton pump inhibitors (PPIs) are potent blockers of gastric acid secretion, which are widely used for treating GERD and peptic ulcer-associated acid-secreting diseases. The effect of PPI therapy on esophageal carcinogenesis remains unclear. While some studies suggest PPIs result in a significant reduction in the risk of developing dysplasia and adenocarcinoma in patients with Barrett's esophagus, others suggest that PPIs have no effect. Recent studies have revealed that PPIs can exert anti-inflammatory effects such as anti-oxidant properties and immunomodulatory effects through their interactions with neutrophils, monocytes, endothelial and epithelial cells. In addition, PPIs have the ability to prevent adhesion molecule binding in malignant cells and suppress metastasis. This article reviews the role of PPIs in esophageal carcinogenesis and their use as antitumor agents.

  4. Postexposure protection of macaques from vaginal SHIV infection by topical integrase inhibitors.

    PubMed

    Dobard, Charles; Sharma, Sunita; Parikh, Urvi M; West, Rolieria; Taylor, Andrew; Martin, Amy; Pau, Chou-Pong; Hanson, Debra L; Lipscomb, Jonathan; Smith, James; Novembre, Francis; Hazuda, Daria; Garcia-Lerma, J Gerardo; Heneine, Walid

    2014-03-12

    Coitally delivered microbicide gels containing antiretroviral drugs are important for HIV prevention. However, to date, microbicides have contained entry or reverse transcriptase inhibitors that block early steps in virus infection and thus need to be given as a preexposure dose that interferes with sexual practices and may limit compliance. Integrase inhibitors block late steps after virus infection and therefore are more suitable for post-coital dosing. We first determined the kinetics of strand transfer in vitro and confirmed that integration begins about 6 hours after infection. We then used a repeat-challenge macaque model to assess efficacy of vaginal gels containing integrase strand transfer inhibitors when applied before or after simian/human immunodeficiency virus (SHIV) challenge. We showed that gel containing the strand transfer inhibitor L-870812 protected two of three macaques when applied 30 min before SHIV challenge. We next evaluated the efficacy of 1% raltegravir gel and demonstrated its ability to protect macaques when applied 3 hours after SHIV exposure (five of six protected; P < 0.05, Fisher's exact test). Breakthrough infections showed no evidence of drug resistance in plasma or vaginal secretions despite continued gel dosing after infection. We documented rapid vaginal absorption reflecting a short pharmacological lag time and noted that vaginal, but not plasma, virus load was substantially reduced in the breakthrough infection after raltegravir gel treatment. We provide a proof of concept that topically applied integrase inhibitors protect against vaginal SHIV infection when administered shortly before or 3 hours after virus exposure.

  5. Fluoro-edenite induces fibulin-3 overexpression in non-malignant human mesothelial cells

    PubMed Central

    Rapisarda, Venerando; Salemi, Rossella; Marconi, Andrea; Loreto, Carla; Graziano, Adriana C.; Cardile, Venera; Basile, Maria S.; Candido, Saverio; Falzone, Luca; Spandidos, Demetrios A.; Fenga, Concettina; Libra, Massimo

    2016-01-01

    Exposure to asbestos is associated with the development of mesothelioma. In addition to asbestos, other fibers have been identified as risk factors for malignant and non-malignant diseases of the lungs. Among these, fluoro-edenite (FE) was found in patients from Biancavilla (Sicily, Italy) with pleural and lung disease, suggesting its role for tumor expansion. In this context, the identification of early biomarkers useful for the diagnosis of cancer is mandatory. Fibulin-3 represents an important marker for the diagnosis of mesothelioma. However, it remains to be determined whether it is directly associated with exposure to asbestos-like fibers. In the present study, peripheral blood levels of fibulin-3 from 40 asbestos-exposed workers were compared with those detected in 27 street cleaners from Biancavilla. Intriguingly, the results showed that fibulin-3 levels were higher in the group of street cleaners compared with those of the asbestos-exposed workers, suggesting that these workers used the personal protective equipment according to the current regulations. These data suggest that subjects exposed to FE should be monitored for the risk of mesothelioma. FE and volcanic particulates are probably contained within dust inhaled by street cleaners from Biancavilla during their work activities. Based on these criteria, in this study, such fibers were used to treat mesothelial cells (MeT5A) in order to verify whether fibulin-3 levels are affected by these treatments. The results showed that only treatment with FE was associated with fibulin-3 overexpression at both the transcript and protein levels. It was previously demonstrated that mesothelial cells exhibited low levels of p27 following treatment with FE. Notably, p27 downregulation is associated with stathmin upregulation in cancer, conferring an aggressive phenotype of tumor cells. This observation prompted us to perform a computational evaluation demonstrating the activation of stathmin in lung cancer in

  6. Dual preventive benefits of iron elimination by desferal in asbestos-induced mesothelial carcinogenesis.

    PubMed

    Jiang, Li; Chew, Shan-Hwu; Nakamura, Kosuke; Ohara, Yuuki; Akatsuka, Shinya; Toyokuni, Shinya

    2016-07-01

    Asbestos-induced mesothelial carcinogenesis is currently a profound social issue due to its extremely long incubation period and high mortality rate. Therefore, procedures to prevent malignant mesothelioma in people already exposed to asbestos are important. In previous experiments, we established an asbestos-induced rat peritoneal mesothelioma model, which revealed that local iron overload is a major cause of pathogenesis and that the induced genetic alterations are similar to human counterparts. Furthermore, we showed that oral administration of deferasirox modified the histology from sarcomatoid to the more favorable epithelioid subtype. Here, we used i.p. administration of desferal to evaluate its effects on asbestos-induced peritoneal inflammation and iron deposition, as well as oxidative stress. Nitrilotriacetate was used to promote an iron-catalyzed Fenton reaction as a positive control. Desferal significantly decreased peritoneal fibrosis, iron deposition, and nuclear 8-hydroxy-2'-deoxyguanosine levels in mesothelial cells, whereas nitrilotriacetate significantly increased all of them. Desferal was more effective in rat peritoneal mesothelial cells to counteract asbestos-induced cytotoxicity than in murine macrophages (RAW264.7). Furthermore, rat sarcomatoid mesothelioma cells were more dependent on iron for proliferation than rat peritoneal mesothelial cells. Because inflammogenicity of a fiber is proportionally associated with subsequent mesothelial carcinogenesis, iron elimination from the mesothelial environment can confer dual merits for preventing asbestos-induced mesothelial carcinogenesis by suppressing inflammation and mesothelial proliferation simultaneously.

  7. Mesothelial cell inclusions in pelvic and para-aortic lymph nodes: a clinicopathologic analysis

    PubMed Central

    Kim, Hyun-Soo; Yoon, Gun; Lee, Yoo-Young; Kim, Tae-Joong; Choi, Chel-Hun; Lee, Jeong-Won; Kim, Byoung-Gie; Bae, Duk-Soo; Song, Sang Yong

    2015-01-01

    Benign lymph node inclusions are commonly encountered during surgery for gynecologic neoplasms and are potential mimics of metastatic tumor. The presence of mesothelial cell inclusions in pelvic lymph nodes is extremely rare. We report the clinicopathologic features of 10 patients with ovarian tumors and mesothelial cell inclusions detected in the sinuses of pelvic and paraaortic lymph nodes. All patients had concurrent massive ascites and mesothelial cell hyperplasia at the time of lymph node dissection. Histologically, nodal mesothelial cells were identified predominantly within the subcapsular, trabecular and medullary sinuses. Moreover, intra- and extranodal lymphatics also contained mesothelial cells, confirming their mode of lymphatic transport to nodal sinuses. This finding, together with mesothelial cell hyperplasia and massive ascites suggest that mesothelial cells derive from reactive serosal mesothelium and are dislodged into draining lymphatics. This study indicated the pathogenic significance of the lymphatic transport mechanism. Nodal mesothelial cell inclusions should be distinguished from metastatic tumor to avoid inaccurate staging in a patient with a known tumor or the false negative diagnosis of an occult primary tumor. Recognition of this entity by immunohistochemical evaluation in addition to routinely stained sections is important to prevent a diagnosis of metastatic carcinoma or malignant mesothelioma. PMID:26191233

  8. MORPHOLOGIC ANALYSIS CORRELATES WITH GENE EXPRESSION CHANGES IN CULTURED F344 RAT MESOTHELIAL CELLS

    EPA Science Inventory

    The gene expression pattern of mesothelial cells in vitro was determined after 4 or 12 h exposure to the rat mesothelial, kidney and thyroid carcinogen, and oxidative stressor potassium bromate (KBr03). Gene expression changes observed using cDNA arrays indicated oxidative stres...

  9. Reactive mesothelial hyperplasia associated with chronic peritonitis in a 20-year-old Quarter horse

    PubMed Central

    Hoon-Hanks, Laura L.; Rout, Emily D.; Vap, Linda M.; Aboellail, Tawfik A.; Hassel, Diana M.; Nout-Lomas, Yvette S.

    2016-01-01

    A 20-year-old gelding was diagnosed with peritonitis and severe reactive mesothelial hyperplasia. Exploratory laparotomy findings were suggestive of a neoplastic etiology; however, additional diagnostics ruled this out and the horse made a full recovery. This report demonstrates the difficulty and value of differentiating between reactive and neoplastic mesothelial processes. PMID:27152035

  10. Differential Effects of Lovastatin on Cisplatin Responses in Normal Human Mesothelial Cells versus Cancer Cells: Implication for Therapy

    PubMed Central

    Shi, Yandong; Felley-Bosco, Emanuela; Marti, Thomas M.; Stahel, Rolf A.

    2012-01-01

    The cancer killing efficacy of standard chemotherapeutic agents such as cisplatin (CDDP) is limited by their side effects to normal tissues. Therefore, research efforts optimizing the safety and efficacy of those agents are clinically relevant. We did screen for agents that specifically protect normal human mesothelial cells against CDDP without reducing the cancer cell killing efficacy. Lovastatin was identified from the screen. Lovastatin at a pharmacologically relevant concentration strongly arrested the proliferation of normal cells, whereas cancer cells were less affected. CDDP-induced DNA damage response was not activated and normal cells showed enhanced tolerance to CDDP when normal cells were treated with the combination of CDDP and lovastatin. We demonstrate that interfering with protein geranylgeranylation is involved in the lovastatin-mediated CDDP protective effect in normal cells. In contrast to normal cells, in cancer cells lovastatin did not change the CDDP-induced response, and cancer cells were not protected by lovastatin. Furthermore, lovastatin at the pharmacological relevant concentration per se induced DNA damage, oxidative stress and autophagy in cancer cells but not in normal mesothelial cells. Therefore, our data suggest that lovastatin has a potential to improve the therapeutic index of cisplatin-based therapy. PMID:23028957

  11. Tamoxifen Ameliorates Peritoneal Membrane Damage by Blocking Mesothelial to Mesenchymal Transition in Peritoneal Dialysis

    PubMed Central

    del Peso, Gloria; Gónzalez-Mateo, Guadalupe; Fernández-Millara, Vanessa; Santamaria, Beatríz; Bajo, Maria Auxiliadora; Sánchez-Tomero, José Antonio; Guerra-Azcona, Gonzalo; Selgas, Rafael; López-Cabrera, Manuel; Aguilera, Abelardo I.

    2013-01-01

    Mesothelial-to-mesenchymal transition (MMT) is an auto-regulated physiological process of tissue repair that in uncontrolled conditions such as peritoneal dialysis (PD) can lead to peritoneal fibrosis. The maximum expression of peritoneal fibrosis induced by PD fluids and other peritoneal processes is the encapsulating peritoneal sclerosis (EPS) for which no specific treatment exists. Tamoxifen, a synthetic estrogen, has successfully been used to treat retroperitoneal fibrosis and EPS associated with PD. Hence, we used in vitro and animal model approaches to evaluate the efficacy of Tamoxifen to inhibit the MMT as a trigger of peritoneal fibrosis. In vitro studies were carried out using omentum-derived mesothelial cells (MCs) and effluent-derived MCs. Tamoxifen blocked the MMT induced by transforming growth factor (TGF)-β1, as it preserved the expression of E-cadherin and reduced the expression of mesenchymal-associated molecules such as snail, fibronectin, collagen-I, α-smooth muscle actin, and matrix metalloproteinse-2. Tamoxifen-treatment preserved the fibrinolytic capacity of MCs treated with TGF-β1 and decreased their migration capacity. Tamoxifen did not reverse the MMT of non-epitheliod MCs from effluents, but it reduced the expression of some mesenchymal molecules. In mice PD model, we demonstrated that MMT progressed in parallel with peritoneal membrane thickness. In addition, we observed that Tamoxifen significantly reduced peritoneal thickness, angiogenesis, invasion of the compact zone by mesenchymal MCs and improved peritoneal function. Tamoxifen also reduced the effluent levels of vascular endothelial growth factor and leptin. These results demonstrate that Tamoxifen is a therapeutic option to treat peritoneal fibrosis, and that its protective effect is mediated via modulation of the MMT process. PMID:23637793

  12. Companion Protease Inhibitors for the In Situ Protection of Recombinant Proteins in Plants.

    PubMed

    Robert, Stéphanie; Jutras, Philippe V; Khalf, Moustafa; D'Aoust, Marc-André; Goulet, Marie-Claire; Sainsbury, Frank; Michaud, Dominique

    2016-01-01

    We previously described a procedure for the use of plant protease inhibitors as "companion" accessory proteins to prevent unwanted proteolysis of clinically useful recombinant proteins in leaf crude protein extracts (Benchabane et al. Methods Mol Biol 483:265-273, 2009). Here we describe the use of these inhibitors for the protection of recombinant proteins in planta, before their extraction from leaf tissues. A procedure is first described involving inhibitors co-expressed along-and co-migrating-with the protein of interest in host plant cells. An alternative, single transgene scheme is then described involving translational fusions of the recombinant protein and companion inhibitor. These approaches may allow for a significant improvement of protein steady-state levels in leaves, comparable to yield improvements observed with protease-deficient strains of less complex protein expression hosts such as E. coli or yeasts.

  13. Selective and potent furin inhibitors protect cells from anthrax without significant toxicity.

    PubMed

    Remacle, Albert G; Gawlik, Katarzyna; Golubkov, Vladislav S; Cadwell, Gregory W; Liddington, Robert C; Cieplak, Piotr; Millis, Sherri Z; Desjardins, Roxane; Routhier, Sophie; Yuan, Xue Wen; Neugebauer, Witold A; Day, Robert; Strongin, Alex Y

    2010-06-01

    Furin and related proprotein convertases cleave the multibasic motifs R-X-R/K/X-R in the precursor proteins and, as a result, transform the latent proproteins into biologically active proteins and peptides. Furin is present both in the intracellular secretory pathway and at the cell surface. Intracellular furin processes its multiple normal cellular targets in the Golgi and secretory vesicle compartments while cell-surface furin appears to be essential only for the processing of certain pathogenic proteins and, importantly, anthrax. To design potent, safe and selective inhibitors of furin, we evaluated the potency and selectivity of the derivatized peptidic inhibitors modeled from the extended furin cleavage sequence of avian influenza A H5N1. We determined that the N- and C-terminal modifications of the original RARRRKKRT inhibitory scaffold produced selective and potent, nanomolar range, inhibitors of furin. These inhibitors did not interfere with the normal cellular function of furin because of the likely functional redundancy existing between furin and other proprotein convertases. These furin inhibitors, however, were highly potent in blocking the furin-dependent cell-surface processing of anthrax protective antigen-83 both in vitro and cell-based assays and in vivo. We conclude that the inhibitors we have designed have a promising potential as selective anthrax inhibitors, without affecting major cell functions.

  14. Inhibitor of apoptosis signal-regulating kinase 1 protects against acetaminophen-induced liver injury

    SciTech Connect

    Xie, Yuchao; Ramachandran, Anup; Breckenridge, David G.; Liles, John T.; Lebofsky, Margitta; Farhood, Anwar; Jaeschke, Hartmut

    2015-07-01

    Metabolic activation and oxidant stress are key events in the pathophysiology of acetaminophen (APAP) hepatotoxicity. The initial mitochondrial oxidative stress triggered by protein adduct formation is amplified by c-jun-N-terminal kinase (JNK), resulting in mitochondrial dysfunction and ultimately cell necrosis. Apoptosis signal-regulating kinase 1 (ASK1) is considered the link between oxidant stress and JNK activation. The objective of the current study was to assess the efficacy and mechanism of action of the small-molecule ASK1 inhibitor GS-459679 in a murine model of APAP hepatotoxicity. APAP (300 mg/kg) caused extensive glutathione depletion, JNK activation and translocation to the mitochondria, oxidant stress and liver injury as indicated by plasma ALT activities and area of necrosis over a 24 h observation period. Pretreatment with 30 mg/kg of GS-459679 almost completely prevented JNK activation, oxidant stress and injury without affecting the metabolic activation of APAP. To evaluate the therapeutic potential of GS-459679, mice were treated with APAP and then with the inhibitor. Given 1.5 h after APAP, GS-459679 was still protective, which was paralleled by reduced JNK activation and p-JNK translocation to mitochondria. However, GS-459679 treatment was not more effective than N-acetylcysteine, and the combination of GS-459679 and N-acetylcysteine exhibited similar efficacy as N-acetylcysteine monotherapy, suggesting that GS-459769 and N-acetylcysteine affect the same pathway. Importantly, inhibition of ASK1 did not impair liver regeneration as indicated by PCNA staining. In conclusion, the ASK1 inhibitor GS-459679 protected against APAP toxicity by attenuating JNK activation and oxidant stress in mice and may have therapeutic potential for APAP overdose patients. - Highlights: • Two ASK1 inhibitors protected against acetaminophen-induced liver injury. • The ASK1 inhibitors protect when used as pre- or post-treatment. • Protection by ASK1 inhibitor is

  15. Enhancement of active corrosion protection via combination of inhibitor-loaded nanocontainers.

    PubMed

    Tedim, J; Poznyak, S K; Kuznetsova, A; Raps, D; Hack, T; Zheludkevich, M L; Ferreira, M G S

    2010-05-01

    The present work reports the synthesis of layered double hydroxides (LDHs) nanocontainers loaded with different corrosion inhibitors (vanadate, phosphate, and 2-mercaptobenzothiazolate) and the characterization of the resulting pigments by X-ray diffraction (XRD) and transmission electron microscopy (TEM). The anticorrosion activity of these nanocontainers with respect to aluminum alloy AA2024 was investigated by electrochemical impedance spectroscopy (EIS). The bare metallic substrates were immersed in dispersions of nanocontainers in sodium chloride solution and tested to understand the inhibition mechanisms and efficiency. The nanocontainers were also incorporated into commercial coatings used for aeronautical applications to study the active corrosion protection properties in systems of industrial relevance. The results show that an enhancement of the active protection effect can be reached when nanocontainers loaded with different inhibitors are combined in the same protective coating system.

  16. A small molecule inhibitor of PAI-1 protects against doxorubicin-induced cellular senescence

    PubMed Central

    Ghosh, Asish K.; Rai, Rahul; Park, Kitae E.; Eren, Mesut; Miyata, Toshio; Wilsbacher, Lisa D.; Vaughan, Douglas E.

    2016-01-01

    Doxorubicin, an anthracycline antibiotic, is a commonly used anticancer drug. In spite of its widespread usage, its therapeutic effect is limited by its cardiotoxicity. On the cellular level, Doxorubicin-induced cardiotoxicity manifests as stress induced premature senescence. Previously, we demonstrated that plasminogen activator inhibitor-1 (PAI-1), a potent inhibitor of serine proteases, is an important biomarker and regulator of cellular senescence and aging. Here, we tested the hypothesis that pharmacological inhibition of cellular PAI-1 protects against stress- and aging-induced cellular senescence and delineated the molecular basis of protective action of PAI-1 inhibition. Results show that TM5441, a potent small molecule inhibitor of PAI-1, effectively prevents Doxorubicin-induced senescence in cardiomyocytes, fibroblasts and endothelial cells. TM5441 exerts its inhibitory effect on Doxorubicin-induced cellular senescence by decreasing reactive oxygen species generation, induction of antioxidants like catalase and suppression of stress-induced senescence cadre p53, p21, p16, PAI-1 and IGFBP3. Importantly, TM5441 also reduces replicative senescence of fibroblasts. Together these results for the first time demonstrate the efficacy of PAI-1 inhibitor in prevention of Doxorubicin-induced and replicative senescence in normal cells. Thus PAI-1 inhibitor may form an important adjuvant component of chemotherapy regimens, limiting not only Doxorubicin-induced cardiac senescence but also ameliorating the prothrombotic profile. PMID:27736799

  17. Tumor exosome-mediated promotion of adhesion to mesothelial cells in gastric cancer cells

    PubMed Central

    Arita, Tomohiro; Ichikawa, Daisuke; Konishi, Hirotaka; Komatsu, Shuhei; Shiozaki, Atsushi; Ogino, Shinpei; Fujita, Yuji; Hiramoto, Hidekazu; Hamada, Junichi; Shoda, Katsutoshi; Kosuga, Toshiyuki; Fujiwara, Hitoshi; Okamoto, Kazuma; Otsuji, Eigo

    2016-01-01

    Background Peritoneal metastasis consists of a highly complex series of steps, and the details of the underlying molecular mechanism remain largely unclear. In this study, the effects of tumor-derived exosomes (TEX) on the progression of gastric cancers were investigated in peritoneal metastasis. Results TEX were internalized in both mesothelial and gastric cancer cells in a cellular origin non-specific manner. Internalization of TEX into mesothelial cells promoted significant adhesion between mesothelial and gastric cancer cells, and TEX internalization into gastric cancer cells significantly promoted migratory ability, while internalization of mesothelial cell-derived exosomes did not. Expression of adhesion-related molecules, such as fibronectin 1 (FN1) and laminin gamma 1 (LAMC1), were increased in mesothelial cells after internalization of TEX from gastric cancer cell line and malignant pleural effusion. Methods TEX were extracted from cell-conditioned medium by ultracentrifugation. The effects of TEX on the malignant potential of gastric cancer were investigated in adhesion, invasion, and proliferation assays. PCR array as well as western blotting were performed to determine the underlying molecular mechanisms. The molecular changes in mesothelial cell after internalization of TEX derived from malignant pleural effusion were also confirmed. Conclusions TEX may play a critical role in the development of peritoneal metastasis of gastric cancer, which may be partially due to inducing increased expression of adhesion molecules in mesothelial cells. PMID:27487135

  18. Protective autophagy is involved in resistance towards MET inhibitors in human gastric adenocarcinoma cells.

    PubMed

    Humbert, Magali; Medová, Michaela; Aebersold, Daniel M; Blaukat, Andree; Bladt, Friedhelm; Fey, Martin F; Zimmer, Yitzhak; Tschan, Mario P

    2013-02-08

    MET, also known as hepatocyte growth factor receptor (HGFR), is a receptor tyrosine kinase with an important role, both in normal cellular function as well as in oncogenesis. In many cancer types, abnormal activation of MET is related to poor prognosis and various strategies to inhibit its function, including small molecule inhibitors, are currently in preclinical and clinical evaluation. Autophagy, a self-digesting recycling mechanism with cytoprotective functions, is induced by cellular stress. This process is also induced upon cytotoxic drug treatment of cancer cells and partially allows these cells to escape cell death. Thus, since autophagy protects different tumor cells from chemotherapy-induced cell death, current clinical trials aim at combining autophagy inhibitors with different cancer treatments. We found that in a gastric adenocarcinoma cell line GTL-16, where MET activity is deregulated due to receptor overexpression, two different MET inhibitors PHA665752 and EMD1214063 lead to cell death paralleled by the induction of autophagy. A combined treatment of MET inhibitors together with the autophagy inhibitor 3-MA or genetically impairing autophagy by knocking down the key autophagy gene ATG7 further decreased cell viability of gastric cancer cells. In general, we observed the induction of cytoprotective autophagy in MET expressing cells upon MET inhibition and a combination of MET and autophagy inhibition resulted in significantly decreased cell viability in gastric cancer cells.

  19. Disruption of iron homeostasis in mesothelial cells after talc pleurodesis.

    PubMed

    Ghio, Andrew J; Soukup, Joleen M; Dailey, Lisa A; Richards, Judy H; Turi, Jennifer L; Pavlisko, Elizabeth N; Roggli, Victor L

    2012-01-01

    The mechanism for biological effects after exposure to particles is incompletely understood. One postulate proposed to explain biological effects after exposure to particles involves altered iron homeostasis in the host. The fibro-inflammatory properties of mineral oxide particles are exploited therapeutically with the instillation of massive quantities of talc into the pleural space, to provide sclerosis. We tested the postulates that (1) in vitro exposure to talc induces a disruption in iron homeostasis, oxidative stress, and a biological effect, and (2) talc pleurodesis in humans alters iron homeostasis. In vitro exposures of both mesothelial and airway epithelial cells to 100 μg/ml talc significantly increased iron importation and concentrations of the storage protein ferritin. Using dichlorodihydrofluorescein, exposure to talc was associated with a time-dependent and concentration-dependent generation of oxidants in both cell types. The expression of proinflammatory mediators was also increased after in vitro exposures of mesothelial and airway epithelial cells to talc. Relative to control lung tissue, lung tissue from patients treated with sclerodesis demonstrated an accumulation of iron and increased expression of iron-related proteins, including ferritin, the importer divalent metal transport-1 and the exporter ferroportin-1. Talc was also observed to translocate to the parenchyma, and changes in iron homeostasis were focally distributed to sites of retention. We conclude that exposure to talc disrupts iron homeostasis, is associated with oxidative stress, and results in a biological effect (i.e., a fibro-inflammatory response). Talc pleurodesis can function as a model of the human response to mineral oxide particle exposure, albeit a massive one.

  20. Protective role of the dynamin inhibitor Dynasore against the cholesterol-dependent cytolysin of Trueperella pyogenes

    PubMed Central

    Preta, Giulio; Lotti, Virginia; Cronin, James G.; Sheldon, I. Martin

    2015-01-01

    The virulence of many Gram-positive bacteria depends on cholesterol-dependent cytolysins (CDCs), which form pores in eukaryotic cell plasma membranes. Pyolysin (PLO) from Trueperella pyogenes provided a unique opportunity to explore cellular responses to CDCs because it does not require thiol activation. Sublytic concentrations of PLO stimulated phosphorylation of MAPK ERK and p38 in primary stromal cells, and induced autophagy as determined by protein light-chain 3B cleavage. Although, inhibitors of MAPK or autophagy did not affect PLO-induced cytolysis. However, 10 μM 3-hydroxynaphthalene-2-carboxylic acid-(3,4-dihydroxybenzylidene)-hydrazide (Dynasore), a dynamin guanosine 5′-triphosphatase inhibitor, protected stromal cells against PLO-induced cytolysis as determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay (85 ± 17% versus 50 ± 9% cell viability), measuring extracellular ATP, and kinetic assays. This was a generalized mechanism because Dynasore also protected HeLa cells against streptolysin O. Furthermore, the effect was reversible, with stromal cell sensitivity to PLO restored within 30 minutes of Dynasore removal. The protective effect of Dynasore was not conferred by dynamin inhibition, induction of ERK phosphorylation, or Dynasore binding to PLO. Rather, Dynasore reduced cellular cholesterol and disrupted plasma membrane lipid rafts, similar to positive control methyl-β-cyclodextrin. Dynasore is a tractable tool to explore the complexity of cholesterol homeostasis in eukaryotic cells and to develop strategies to counter CDCs.—Preta, G., Lotti, V., Cronin, J. G., and Sheldon, I. M. Protective role of the dynamin inhibitor Dynasore against the cholesterol-dependent cytolysin of Trueperella pyogenes. PMID:25550455

  1. Small-molecule inhibitors of lethal factor protease activity protect against anthrax infection.

    PubMed

    Moayeri, Mahtab; Crown, Devorah; Jiao, Guan-Sheng; Kim, Seongjin; Johnson, Alan; Leysath, Clinton; Leppla, Stephen H

    2013-09-01

    Bacillus anthracis, the causative agent of anthrax, manifests its pathogenesis through the action of two secreted toxins. The bipartite lethal and edema toxins, a combination of lethal factor or edema factor with the protein protective antigen, are important virulence factors for this bacterium. We previously developed small-molecule inhibitors of lethal factor proteolytic activity (LFIs) and demonstrated their in vivo efficacy in a rat lethal toxin challenge model. In this work, we show that these LFIs protect against lethality caused by anthrax infection in mice when combined with subprotective doses of either antibiotics or neutralizing monoclonal antibodies that target edema factor. Significantly, these inhibitors provided protection against lethal infection when administered as a monotherapy. As little as two doses (10 mg/kg) administered at 2 h and 8 h after spore infection was sufficient to provide a significant survival benefit in infected mice. Administration of LFIs early in the infection was found to inhibit dissemination of vegetative bacteria to the organs in the first 32 h following infection. In addition, neutralizing antibodies against edema factor also inhibited bacterial dissemination with similar efficacy. Together, our findings confirm the important roles that both anthrax toxins play in establishing anthrax infection and demonstrate the potential for small-molecule therapeutics targeting these proteins.

  2. Expression of adhesion molecules and chemotactic cytokines in cultured human mesothelial cells.

    PubMed

    Jonjić, N; Peri, G; Bernasconi, S; Sciacca, F L; Colotta, F; Pelicci, P; Lanfrancone, L; Mantovani, A

    1992-10-01

    The mesothelium is a flat epithelial lining of serous cavities that could gate the traffic of molecules and cells between the circulation and these body compartments. The present study was designed to elucidate the capacity of mesothelial cells to express adhesion molecules and chemoattractant cytokines, two fundamental mechanisms of regulation of leukocyte recruitment. Cultured human mesothelial cells express appreciable levels of intercellular adhesion molecule 1 (ICAM-1) and vascular cell adhesion molecule 1 (VCAM-1), and these were increased by in vitro exposure to tumor necrosis factor (TNF), interferon gamma (IFN-gamma), or TNF and IFN-gamma. Interleukin 1 (IL-1) was a less consistent stimulus for adhesion molecule expression in vitro. Unlike endothelial cells, used as a reference cell population, resting or stimulated mesothelial cells did not express E-selectin and ICAM-2, as assessed by flow cytometry. Analysis of VCAM-1 mRNA by reverse transcriptase and polymerase chain reaction using appropriate primers revealed that mesothelial cells expressed both the seven- and the six-Ig domain transcripts, with predominance of the longer species. Monocytes bound appreciably to "resting" and, to a greater extent, to stimulated mesothelial cells. Monocytes exposed to IFN-gamma and lipopolysaccharide, used as prototypic activation signals, showed increased capacity to bind mesothelial cells. Anti-CD18 monoclonal antibody significantly inhibited binding of monocytes to mesothelial cells, and this blocking effect was amplified by anti-very late antigen 4. Mesothelial cells were able to express the chemotactic cytokines IL-8 and monocyte chemotactic protein 1 at the mRNA and protein levels. These results indicate that mesothelial cells can express a set of adhesion molecules (ICAM-1 and VCAM-1) overlapping with, but distinct from, that expressed in vascular endothelium (ICAM-1, ICAM-2, VCAM-1, E-selectin), and that these are functionally relevant for interacting with

  3. Differential Susceptibility of Human Pleural and Peritoneal Mesothelial Cells to Asbestos Exposure.

    PubMed

    Dragon, Julie; Thompson, Joyce; MacPherson, Maximilian; Shukla, Arti

    2015-08-01

    Malignant mesothelioma (MM) is an aggressive cancer of mesothelial cells of pleural and peritoneal cavities. In 85% of cases both pleural and peritoneal MM is caused by asbestos exposure. Although both are asbestos-induced cancers, the incidence of pleural MM is significantly higher (85%) than peritoneal MM (15%). It has been proposed that carcinogenesis is a result of asbestos-induced inflammation but it is not clear what contributes to the differences observed between incidences of these two cancers. We hypothesize that the observed differences in incidences of pleural and peritoneal MM are the result of differences in the direct response of these cell types to asbestos rather than to differences mediated by the in vivo microenvironment. To test this hypothesis we characterized cellular responses to asbestos in a controlled environment. We found significantly greater changes in genome-wide expression in response to asbestos exposure in pleural mesothelial cells as compared to peritoneal mesothelial cells. In particular, a greater response in many common genes (IL-8, ATF3, CXCL2, CXCL3, IL-6, GOS2) was seen in pleural mesothelial cells as compared to peritoneal mesothelial cells. Unique genes expressed in pleural mesothelial cells were mainly pro-inflammatory (G-CSF, IL-1β, IL-1α, GREM1) and have previously been shown to be involved in development of MM. Our results are consistent with the hypothesis that differences in incidences of pleural and peritoneal MM upon exposure to asbestos are the result of differences in mesothelial cell physiology that lead to differences in the inflammatory response, which leads to cancer.

  4. Differential susceptibility of human pleural and peritoneal mesothelial cells to asbestos exposure

    PubMed Central

    Dragon, Julie; Thompson, Joyce; MacPherson, Maximilian; Shukla, Arti

    2015-01-01

    Malignant mesothelioma (MM) is an aggressive cancer of mesothelial cells of pleural and peritoneal cavities. In 85% of cases both pleural and peritoneal MM is caused by asbestos exposure. Although both are asbestos-induced cancers, the incidence of pleural MM is significantly higher (85%) than peritoneal MM (15%). It has been proposed that carcinogenesis is a result of asbestos-induced inflammation but it is not clear what contributes to the differences observed between incidences of these two cancers. We hypothesize that the observed differences in incidences of pleural and peritoneal MM are the result of differences in the direct response of these cell types to asbestos rather than to differences mediated by the in vivo microenvironment. To test this hypothesis we characterized cellular responses to asbestos in a controlled environment. We found significantly greater changes in genome-wide expression in response to asbestos exposure in pleural mesothelial cells as compared to peritoneal mesothelial cells. In particular, a greater response in many common genes (IL-8, ATF3, CXCL2, CXCL3, IL-6, GOS2) was seen in pleural mesothelial cells as compared to peritoneal mesothelial cells. Unique genes expressed in pleural mesothelial cells were mainly pro-inflammatory (G-CSF, IL-1β, IL-1α, GREM1) and have previously been shown to be involved in development of MM. Our results are consistent with the hypothesis that differences in incidences of pleural and peritoneal MM upon exposure to asbestos are the result of differences in mesothelial cell physiology that lead to differences in the inflammatory response, which leads to cancer. PMID:25757056

  5. Suberoylanilide hydroxamic acid, a histone deacetylase inhibitor, protects dopaminergic neurons from neurotoxin-induced damage

    PubMed Central

    Chen, SH; Wu, HM; Ossola, B; Schendzielorz, N; Wilson, BC; Chu, CH; Chen, SL; Wang, Q; Zhang, D; Qian, L; Li, X; Hong, JS; Lu, RB

    2012-01-01

    BACKGROUND AND PURPOSE Prevention or disease-modifying therapies are critical for the treatment of neurodegenerative disorders such as Alzheimer's disease, Parkinson's disease and Huntington's disease. However, no such intervention is currently available. Growing evidence has demonstrated that administration of histone deacetylase (HDAC) inhibitors ameliorates a wide range of neurologic and psychiatric disorders in experimental models. Suberoylanilide hydroxamic acid (SAHA) was the first HDAC inhibitor approved by the Food and Drug Administration for the sole use of cancer therapy. The purpose of this study was to explore the potential new indications of SAHA for therapy of neurodegenerative diseases in in vitro Parkinson's disease models. EXPERIMENTAL APPROACH Mesencephalic neuron–glia cultures and reconstituted cultures were used to investigate neurotrophic and neuroprotective effects of SAHA. We measured toxicity in dopaminergic neurons, using dopamine uptake assay and morphological analysis and expression of neurotrophic substances by enzyme-linked immunosorbent assay and real-time RT PCR. KEY RESULTS In mesencephalic neuron–glia cultures, SAHA displayed dose- and time-dependent prolongation of the survival and protection against neurotoxin-induced neuronal death of dopaminergic neurons. Mechanistic studies revealed that the neuroprotective effects of SAHA were mediated in part by promoting release of neurotrophic factors from astroglia through inhibition of histone deacetylation. CONCLUSION AND IMPLICATIONS The novel neurotrophic and neuroprotective effects of SAHA demonstrated in this study suggest that further study of this HDAC inhibitor could provide a new therapeutic approach to the treatment of neurodegenerative diseases. PMID:21726209

  6. Surface-modified particles loaded with CaMKII inhibitor protect cardiac cells against mitochondrial injury.

    PubMed

    Wongrakpanich, Amaraporn; Morris, Angie S; Geary, Sean M; Joiner, Mei-Ling A; Salem, Aliasger K

    2017-03-30

    An excess of calcium (Ca(2+)) influx into mitochondria during mitochondrial re-energization is one of the causes of myocardial cell death during ischemic/reperfusion injury. This overload of Ca(2+) triggers the mitochondrial permeability transition pore (mPTP) opening which leads to programmed cell death. During the ischemic/reperfusion stage, the activated Ca(2+)/calmodulin-dependent protein kinase II (CaMKII) enzyme is responsible for Ca(2+) influx. To reduce CaMKII-related cell death, sub-micron particles composed of poly(lactic-co-glycolic acid) (PLGA), loaded with a CaMKII inhibitor peptide were fabricated. The CaMKII inhibitor peptide-loaded (CIP) particles were coated with a mitochondria targeting moiety, triphenylphosphonium cation (TPP), which allowed the particles to accumulate and release the peptide inside mitochondria to inhibit CaMKII activity. The fluorescently labeled TPP-CIP was taken up by mitochondria and successfully reduced reactive oxygen species (ROS) caused by Isoprenaline (ISO) in a differentiated rat cardiomyocyte-like cell line. When cells were treated with TPP-CIP prior to ISO exposure, they maintained mitochondrial membrane potential. The TPP-CIP protected cells from ISO-induced ROS production and decreased mitochondrial membrane potential. Thus, TPP-CIP has the potential to be used in protection against ischemia/reperfusion injury.

  7. Phagocytosis of dying tumor cells by human peritoneal mesothelial cells.

    PubMed

    Wagner, Britta Janina; Lindau, Dennis; Ripper, Dagmar; Stierhof, York-Dieter; Glatzle, Jörg; Witte, Maria; Beck, Henning; Keppeler, Hildegard; Lauber, Kirsten; Rammensee, Hans-Georg; Königsrainer, Alfred

    2011-05-15

    Peritoneal carcinomatosis is an advanced form of metastatic disease characterized by cancer cell dissemination onto the peritoneum. It is commonly observed in ovarian and colorectal cancers and is associated with poor patient survival. Novel therapies consist of cytoreductive surgery in combination with intraperitoneal chemotherapy, aiming at tumor cell death induction. The resulting dying tumor cells are considered to be eliminated by professional as well as semi-professional phagocytes. In the present study, we have identified a hitherto unknown type of 'amateur' phagocyte in this environment: human peritoneal mesothelial cells (HMCs). We demonstrate that HMCs engulf corpses of dying ovarian and colorectal cancer cells, as well as other types of apoptotic cells. Flow cytometric, confocal and electron microscopical analyses revealed that HMCs ingest dying cell fragments in a dose- and time-dependent manner and the internalized material subsequently traffics into late phagolysosomes. Regarding the mechanisms of prey cell recognition, our results show that HMCs engulf apoptotic corpses in a serum-dependent and -independent fashion and quantitative real-time PCR (qRT-PCR) analyses revealed that diverse opsonin receptor systems orchestrating dying cell clearance are expressed in HMCs at high levels. Our data strongly suggest that HMCs contribute to dying cell removal in the peritoneum, and future studies will elucidate in what manner this influences tumor cell dissemination and the antitumor immune response.

  8. Cholesterol synthesis inhibitors protect against platelet-activating factor-induced neuronal damage

    PubMed Central

    Bate, Clive; Rumbold, Louis; Williams, Alun

    2007-01-01

    Background Platelet-activating factor (PAF) is implicated in the neuronal damage that accompanies ischemia, prion disease and Alzheimer's disease (AD). Since some epidemiological studies demonstrate that statins, drugs that reduce cholesterol synthesis, have a beneficial effect on mild AD, we examined the effects of two cholesterol synthesis inhibitors on neuronal responses to PAF. Methods Primary cortical neurons were treated with cholesterol synthesis inhibitors (simvastatin or squalestatin) prior to incubation with different neurotoxins. The effects of these drugs on neuronal cholesterol levels and neuronal survival were measured. Immunoblots were used to determine the effects of simvastatin or squalestatin on the distribution of the PAF receptor and an enzyme linked immunoassay was used to quantify the amounts of PAF receptor. Results PAF killed primary neurons in a dose-dependent manner. Pre-treatment with simvastatin or squalestatin reduced neuronal cholesterol and increased the survival of PAF-treated neurons. Neuronal survival was increased 50% by 100 nM simvastatin, or 20 nM squalestatin. The addition of mevalonate restored cholesterol levels, and reversed the protective effect of simvastatin. Simvastatin or squalestatin did not affect the amounts of the PAF receptor but did cause it to disperse from within lipid rafts. Conclusion Treatment of neurons with cholesterol synthesis inhibitors including simvastatin and squalestatin protected neurons against PAF. Treatment caused a percentage of the PAF receptors to disperse from cholesterol-sensitive domains. These results raise the possibility that the effects of statins on neurodegenerative disease are, at least in part, due to desensitisation of neurons to PAF. PMID:17233902

  9. The sulphydryl containing ACE inhibitor Zofenoprilat protects coronary endothelium from Doxorubicin-induced apoptosis.

    PubMed

    Monti, Martina; Terzuoli, Erika; Ziche, Marina; Morbidelli, Lucia

    2013-10-01

    Pediatric and adult cancer patients, following the use of the antitumor drug Doxorubicin develop cardiotoxicity. Pharmacological protection of microvascular endothelium might produce a double benefit: (i) reduction of myocardial toxicity (the primary target of Doxorubicin action) and (ii) maintenance of the vascular functionality for the adequate delivery of chemotherapeutics to tumor cells. This study was aimed to evaluate the mechanisms responsible of the protective effects of the angiotensin converting enzyme inhibitor (ACEI) Zofenoprilat against the toxic effects exerted by Doxorubicin on coronary microvascular endothelium. We found that exposure of endothelial cells to Doxorubicin (0.1-1μM range) impaired cell survival by promoting their apoptosis. ERK1/2 related p53 activation, but not reactive oxygen species, was responsible for Doxorubicin induced caspase-3 cleavage. P53 mediated-apoptosis and impairment of survival were reverted by treatment with Zofenoprilat. The previously described PI-3K/eNOS/endogenous fibroblast growth factor signaling was not involved in the protective effect, which, instead, could be ascribed to cystathionine gamma lyase dependent availability of H2S from Zofenoprilat. Furthermore, considering the tumor environment, the treatment of endothelial/tumor co-cultures with Zofenoprilat did not affect the antitumor efficacy of Doxorubicin. In conclusion the ACEI Zofenoprilat exerts a protective effect on Doxorubicin induced endothelial damage, without affecting its antitumor efficacy. Thus, sulfhydryl containing ACEI may be a useful therapy for Doxorubicin-induced cardiotoxicity.

  10. The angiotensin converting enzyme inhibitor captopril protects nigrostriatal dopamine neurons in animal models of parkinsonism.

    PubMed

    Sonsalla, Patricia K; Coleman, Christal; Wong, Lai-Yoong; Harris, Suzan L; Richardson, Jason R; Gadad, Bharathi S; Li, Wenhao; German, Dwight C

    2013-12-01

    Parkinson's disease (PD) is a progressive neurodegenerative disorder characterized by a prominent loss of nigrostriatal dopamine (DA) neurons with an accompanying neuroinflammation. The peptide angiotensin II (AngII) plays a role in oxidative-stress induced disorders and is thought to mediate its detrimental actions via activation of AngII AT1 receptors. The brain renin-angiotensin system is implicated in neurodegenerative disorders including PD. Blockade of the angiotensin converting enzyme or AT1 receptors provides protection in acute animal models of parkinsonism. We demonstrate here that treatment of mice with the angiotensin converting enzyme inhibitor captopril protects the striatum from acutely administered 1-methyl-4-phenyl-1,2,3,6-tetrahydropyrine (MPTP), and that chronic captopril protects the nigral DA cell bodies from degeneration in a progressive rat model of parkinsonism created by the chronic intracerebral infusion of 1-methyl-4-phenylpyridinium (MPP+). The accompanying activation of microglia in the substantia nigra of MPP+-treated rats was reduced by the chronic captopril treatment. These findings indicate that captopril is neuroprotective for nigrostriatal DA neurons in both acute and chronic rodent PD models. Targeting the brain AngII pathway may be a feasible approach to slowing neurodegeneration in PD.

  11. Cancer-promoting role of adipocytes in asbestos-induced mesothelial carcinogenesis through dysregulated adipocytokine production.

    PubMed

    Chew, Shan Hwu; Okazaki, Yasumasa; Nagai, Hirotaka; Misawa, Nobuaki; Akatsuka, Shinya; Yamashita, Kyoko; Jiang, Li; Yamashita, Yoriko; Noguchi, Michio; Hosoda, Kiminori; Sekido, Yoshitaka; Takahashi, Takashi; Toyokuni, Shinya

    2014-01-01

    Like many other human cancers, the development of malignant mesothelioma is closely associated with a chronic inflammatory condition. Both macrophages and mesothelial cells play crucial roles in the inflammatory response caused by asbestos exposure. Here, we show that adipocytes can also contribute to asbestos-induced inflammation through dysregulated adipocytokine production. 3T3-L1 preadipocytes were differentiated into mature adipocytes prior to use. These cells took up asbestos fibers (chrysotile, crocidolite and amosite) but were more resistant to asbestos-induced injury than macrophages and mesothelial cells. Expression microarray analysis followed by reverse transcription-PCR revealed that adipocytes respond directly to asbestos exposure with an increased production of proinflammatory adipocytokines [e.g. monocyte chemoattractant protein-1 (MCP-1)], whereas the production of anti-inflammatory adipocytokines (e.g. adiponectin) is suppressed. This was confirmed in epididymal fat pad of mice after intraperitoneal injection of asbestos fibers. Such dysregulated adipocytokine production favors the establishment of a proinflammatory environment. Furthermore, MCP-1 marginally promoted the growth of MeT-5A mesothelial cells and significantly enhanced the wound healing of Y-MESO-8A and Y-MESO-8D human mesothelioma cells. Our results suggest that increased levels of adipocytokines, such as MCP-1, can potentially contribute to the promotion of mesothelial carcinogenesis through the enhanced recruitment of inflammatory cells as well as a direct growth and migration stimulatory effect on mesothelial and mesothelioma cells. Taken together, our findings support a potential cancer-promoting role of adipocytes in asbestos-induced mesothelial carcinogenesis.

  12. Asbestos-Induced Mesothelial to Fibroblastic Transition Is Modulated by the Inflammasome.

    PubMed

    Thompson, Joyce K; MacPherson, Maximilian B; Beuschel, Stacie L; Shukla, Arti

    2017-03-01

    Despite the causal relationship established between malignant mesothelioma (MM) and asbestos exposure, the exact mechanism by which asbestos induces this neoplasm and other asbestos-related diseases is still not well understood. MM is characterized by chronic inflammation, which is believed to play an intrinsic role in the origin of this disease. We recently found that asbestos activates the nod-like receptor family member containing a pyrin domain 3 (NLRP3) inflammasome in a protracted manner, leading to an up-regulation of IL-1β and IL-18 production in human mesothelial cells. Combined with biopersistence of asbestos fibers, we hypothesize that this creates an environment of chronic IL-1β signaling in human mesothelial cells, which may promote mesothelial to fibroblastic transition (MFT) in an NLRP3-dependent manner. Using a series of experiments, we found that asbestos induces a fibroblastic transition of mesothelial cells with a gain of mesenchymal markers (vimentin and N-cadherin), whereas epithelial markers, such as E-cadherin, are down-regulated. Use of siRNA against NLRP3, recombinant IL-1β, and IL-1 receptor antagonist confirmed the role of NLRP3 inflammasome-dependent IL-1β in the process. In vivo studies using wild-type and various inflammasome component knockout mice also revealed the process of asbestos-induced mesothelial to fibroblastic transition and its amelioration in caspase-1 knockout mice. Taken together, our data are the first to suggest that asbestos induces mesothelial to fibroblastic transition in an inflammasome-dependent manner.

  13. Pleural mesothelial cells in pleural and lung diseases

    PubMed Central

    Antony, Veena B.

    2015-01-01

    During development, the mesoderm maintains a complex relationship with the developing endoderm giving rise to the mature lung. Pleural mesothelial cells (PMCs) derived from the mesoderm play a key role during the development of the lung. The pleural mesothelium differentiates to give rise to the endothelium and smooth muscle cells via epithelial-to-mesenchymal transition (EMT). An aberrant recapitulation of such developmental pathways can play an important role in the pathogenesis of disease processes such as idiopathic pulmonary fibrosis (IPF). The PMC is the central component of the immune responses of the pleura. When exposed to noxious stimuli, it demonstrates innate immune responses such as Toll-like receptor (TLR) recognition of pathogen associated molecular patterns as well as causes the release of several cytokines to activate adaptive immune responses. Development of pleural effusions occurs due to an imbalance in the dynamic interaction between junctional proteins, n-cadherin and β-catenin, and phosphorylation of adherens junctions between PMCs, which is caused in part by vascular endothelial growth factor (VEGF) released by PMCs. PMCs play an important role in defense mechanisms against bacterial and mycobacterial pleural infections, and in pathogenesis of malignant pleural effusion, asbestos related pleural disease and malignant pleural mesothelioma. PMCs also play a key role in the resolution of inflammation, which can occur with or without fibrosis. Fibrosis occurs as a result of disordered fibrin turnover and due to the effects of cytokines such as transforming growth factor-β, platelet-derived growth factor (PDGF), and basic fibroblast growth factor; which are released by PMCs. Recent studies have demonstrated a role for PMCs in the pathogenesis of IPF suggesting their potential as a cellular biomarker of disease activity and as a possible therapeutic target. Pleural-based therapies targeting PMCs for treatment of IPF and other lung diseases need

  14. A GSK-3β Inhibitor Protects Against Radiation Necrosis in Mouse Brain

    SciTech Connect

    Jiang, Xiaoyu; Perez-Torres, Carlos J.; Thotala, Dinesh; Engelbach, John A.; Yuan, Liya; Cates, Jeremy; Gao, Feng; Drzymala, Robert E.; Rich, Keith M.; Schmidt, Robert E.; Ackerman, Joseph J.H.; Hallahan, Dennis E.; Garbow, Joel R.

    2014-07-15

    Purpose: To quantify the effectiveness of SB415286, a specific inhibitor of GSK-3β, as a neuroprotectant against radiation-induced central nervous system (brain) necrosis in a mouse model. Methods and Materials: Cohorts of mice were treated with SB415286 or dimethyl sulfoxide (DMSO) prior to irradiation with a single 45-Gy fraction targeted to the left hemisphere (brain) using a gamma knife machine. The onset and progression of radiation necrosis (RN) were monitored longitudinally by noninvasive in vivo small-animal magnetic resonance imaging (MRI) beginning 13 weeks postirradiation. MRI-derived necrotic volumes for SB415286- and DMSO-treated mice were compared. MRI results were supported by correlative histology. Results: Mice treated with SB415286 showed significant protection from radiation-induced necrosis, as determined by in vivo MRI with histologic validation. MRI-derived necrotic volumes were significantly smaller at all postirradiation time points in SB415286-treated animals. Although the irradiated hemispheres of the DMSO-treated mice demonstrated many of the classic histologic features of RN, including fibrinoid vascular necrosis, vascular telangiectasia, hemorrhage, and tissue loss, the irradiated hemispheres of the SB415286-treated mice consistently showed only minimal tissue damage. These studies confirmed that treatment with a GSK-3β inhibitor dramatically reduced delayed time-to-onset necrosis in irradiated brain. Conclusions: The unilateral cerebral hemispheric stereotactic radiation surgery mouse model in concert with longitudinal MRI monitoring provided a powerful platform for studying the onset and progression of RN and for developing and testing new neuroprotectants. Effectiveness of SB415286 as a neuroprotectant against necrosis motivates potential clinical trials of it or other GSK-3β inhibitors.

  15. The role of plasminogen activator inhibitor-1 in gastric mucosal protection

    PubMed Central

    Kenny, Susan; Steele, Islay; Lyons, Suzanne; Moore, Andrew R.; Murugesan, Senthil V.; Tiszlavicz, Laszlo; Dimaline, Rod; Pritchard, D. Mark; Varro, Andrea

    2013-01-01

    Gastric mucosal health is maintained in response to potentially damaging luminal factors. Aspirin and nonsteroidal anti-inflammatory drugs (NSAIDs) disrupt protective mechanisms leading to bleeding and ulceration. The plasminogen activator system has been implicated in fibrinolysis following gastric ulceration, and an inhibitor of this system, plasminogen activator inhibitor (PAI)-1, is expressed in gastric epithelial cells. In Helicobacter pylori-negative patients with normal gastric histology taking aspirin or NSAIDs, we found elevated gastric PAI-1 mRNA abundance compared with controls; the increase in patients on aspirin was independent of whether they were also taking proton pump inhibitors. In the same patients, aspirin tended to lower urokinase plasminogen activator mRNA. Immunohistochemistry indicated PAI-1 localization to epithelial cells. In a model system using MKN45 or AGS-GR cells transfected with a PAI-1 promoter-luciferase reporter construct, we found no evidence for upregulation of PAI-1 expression by indomethacin, and, in fact, cyclooxygenase products such as PGE2 and PGI2 weakly stimulated expression. Increased gastric PAI-1 mRNA was also found in mice following gavage with ethanol or indomethacin, but plasma PAI-1 was unaffected. In PAI-1−/− mice, gastric hemorrhagic lesions in response to ethanol or indomethacin were increased compared with C57BL/6 mice. In contrast, in PAI-1-H/Kβ mice in which PAI-1 is overexpressed in parietal cells, there were decreased lesions in response to ethanol and indomethacin. Thus, PAI-1 expression is increased in gastric epithelial cells in response to mucosal irritants such as aspirin and NSAIDs probably via an indirect mechanism, and PAI-1 acts as a local autoregulator to minimize mucosal damage. PMID:23494120

  16. Small-molecule quinolinol inhibitor identified provides protection against BoNT/A in mice.

    PubMed

    Singh, Padma; Singh, Manglesh Kumar; Chaudhary, Dilip; Chauhan, Vinita; Bharadwaj, Pranay; Pandey, Apurva; Upadhyay, Nisha; Dhaked, Ram Kumar

    2012-01-01

    Botulinum neurotoxins (BoNTs), etiological agents of the life threatening neuroparalytic disease botulism, are the most toxic substances currently known. The potential for the use as bioweapon makes the development of small-molecule inhibitor against these deadly toxins is a top priority. Currently, there are no approved pharmacological treatments for BoNT intoxication. Although an effective vaccine/immunotherapy is available for immuno-prophylaxis but this cannot reverse the effects of toxin inside neurons. A small-molecule pharmacological intervention, especially one that would be effective against the light chain protease, would be highly desirable. Similarity search was carried out from ChemBridge and NSC libraries to the hit (7-(phenyl(8-quinolinylamino)methyl)-8-quinolinol; NSC 84096) to mine its analogs. Several hits obtained were screened for in silico inhibition using AutoDock 4.1 and 19 new molecules selected based on binding energy and Ki. Among these, eleven quinolinol derivatives potently inhibited in vitro endopeptidase activity of botulinum neurotoxin type A light chain (rBoNT/A-LC) on synaptosomes isolated from rat brain which simulate the in vivo system. Five of these inhibitor molecules exhibited IC(50) values ranging from 3.0 nM to 10.0 µM. NSC 84087 is the most potent inhibitor reported so far, found to be a promising lead for therapeutic development, as it exhibits no toxicity, and is able to protect animals from pre and post challenge of botulinum neurotoxin type A (BoNT/A).

  17. Small-Molecule Quinolinol Inhibitor Identified Provides Protection against BoNT/A in Mice

    PubMed Central

    Singh, Padma; Singh, Manglesh Kumar; Chaudhary, Dilip; Chauhan, Vinita; Bharadwaj, Pranay; Pandey, Apurva; Upadhyay, Nisha; Dhaked, Ram Kumar

    2012-01-01

    Botulinum neurotoxins (BoNTs), etiological agents of the life threatening neuroparalytic disease botulism, are the most toxic substances currently known. The potential for the use as bioweapon makes the development of small-molecule inhibitor against these deadly toxins is a top priority. Currently, there are no approved pharmacological treatments for BoNT intoxication. Although an effective vaccine/immunotherapy is available for immuno-prophylaxis but this cannot reverse the effects of toxin inside neurons. A small-molecule pharmacological intervention, especially one that would be effective against the light chain protease, would be highly desirable. Similarity search was carried out from ChemBridge and NSC libraries to the hit (7-(phenyl(8-quinolinylamino)methyl)-8-quinolinol; NSC 84096) to mine its analogs. Several hits obtained were screened for in silico inhibition using AutoDock 4.1 and 19 new molecules selected based on binding energy and Ki. Among these, eleven quinolinol derivatives potently inhibited in vitro endopeptidase activity of botulinum neurotoxin type A light chain (rBoNT/A-LC) on synaptosomes isolated from rat brain which simulate the in vivo system. Five of these inhibitor molecules exhibited IC50 values ranging from 3.0 nM to 10.0 µM. NSC 84087 is the most potent inhibitor reported so far, found to be a promising lead for therapeutic development, as it exhibits no toxicity, and is able to protect animals from pre and post challenge of botulinum neurotoxin type A (BoNT/A). PMID:23071727

  18. Phospholipase A2 inhibitors protect against prion and Aβ mediated synapse degeneration

    PubMed Central

    2010-01-01

    Background An early event in the neuropathology of prion and Alzheimer's diseases is the loss of synapses and a corresponding reduction in the level of synaptophysin, a pre-synaptic membrane protein essential for neurotransmission. The molecular mechanisms involved in synapse degeneration in these diseases are poorly understood. In this study the process of synapse degeneration was investigated by measuring the synaptophysin content of cultured neurones incubated with the prion derived peptide (PrP82-146) or with Aβ1-42, a peptide thought to trigger pathogenesis in Alzheimer's disease. A pharmacological approach was used to screen cell signalling pathways involved in synapse degeneration. Results Pre-treatment with phospholipase A2 inhibitors (AACOCF3, MAFP and aristolochic acids) protected against synapse degeneration in cultured cortical and hippocampal neurones incubated with PrP82-146 or Aβ1-42. Synapse degeneration was also observed following the addition of a specific phospholipase A2 activating peptide (PLAP) and the addition of PrP82-146 or Aβ1-42 activated cytoplasmic phospholipase A2 within synapses. Activation of phospholipase A2 is the first step in the generation of platelet-activating factor (PAF) and PAF receptor antagonists (ginkgolide B, Hexa-PAF and CV6029) protected against synapse degeneration induced by PrP82-146, Aβ1-42 and PLAP. PAF facilitated the production of prostaglandin E2, which also caused synapse degeneration and pre-treatment with the prostanoid E receptor antagonist AH13205 protected against PrP82-146, Aβ1-42 and PAF induced synapse degeneration. Conclusions Our results are consistent with the hypothesis that PrP82-146 and Aβ1-42trigger abnormal activation of cytoplasmic phospholipase A2 resident within synapses, resulting in elevated levels of PAF and prostaglandin E2that cause synapse degeneration. Inhibitors of this pathway that can cross the blood brain barrier may protect against the synapse degeneration seen during

  19. Hsp90 inhibitor 17-AAG sensitizes Bcl-2 inhibitor (-)-gossypol by suppressing ERK-mediated protective autophagy and Mcl-1 accumulation in hepatocellular carcinoma cells.

    PubMed

    Wang, Bin; Chen, Linfeng; Ni, Zhenhong; Dai, Xufang; Qin, Liyan; Wu, Yaran; Li, Xinzhe; Xu, Liang; Lian, Jiqin; He, Fengtian

    2014-11-01

    Natural BH3-memitic (-)-gossypol shows promising antitumor efficacy in several kinds of cancer. However, our previous studies have demonstrated that protective autophagy decreases the drug sensitivities of Bcl-2 inhibitors in hepatocellular carcinoma (HCC) cells. In the present study, we are the first to report that Hsp90 inhibitor 17-AAG enhanced (-)-gossypol-induced apoptosis via suppressing (-)-gossypol-triggered protective autophagy and Mcl-1 accumulation. The suppression effect of 17-AAG on autophagy was mediated by inhibiting ERK-mediated Bcl-2 phosphorylation while was not related to Beclin1 or LC3 protein instability. Meanwhile, 17-AAG downregulated (-)-gossypol-triggered Mcl-1 accumulation by suppressing Mcl-1(Thr163) phosphorylation and promoting protein degradation. Collectively, our study indicates that Hsp90 plays an important role in tumor maintenance and inhibition of Hsp90 may become a new strategy for sensitizing Bcl-2-targeted chemotherapies in HCC cells.

  20. Protection of macaques from vaginal SHIV challenge by vaginally delivered inhibitors of virus-cell fusion.

    PubMed

    Veazey, Ronald S; Klasse, Per Johan; Schader, Susan M; Hu, Qinxue; Ketas, Thomas J; Lu, Min; Marx, Preston A; Dufour, Jason; Colonno, Richard J; Shattock, Robin J; Springer, Martin S; Moore, John P

    2005-11-03

    Human immunodeficiency virus type 1 (HIV-1) continues to spread, principally by heterosexual sex, but no vaccine is available. Hence, alternative prevention methods are needed to supplement educational and behavioural-modification programmes. One such approach is a vaginal microbicide: the application of inhibitory compounds before intercourse. Here, we have evaluated the microbicide concept using the rhesus macaque 'high dose' vaginal transmission model with a CCR5-receptor-using simian-human immunodeficiency virus (SHIV-162P3) and three compounds that inhibit different stages of the virus-cell attachment and entry process. These compounds are BMS-378806, a small molecule that binds the viral gp120 glycoprotein and prevents its attachment to the CD4 and CCR5 receptors, CMPD167, a small molecule that binds to CCR5 to inhibit gp120 association, and C52L, a bacterially expressed peptide inhibitor of gp41-mediated fusion. In vitro, all three compounds inhibit infection of T cells and cervical tissue explants, and C52L acts synergistically with CMPD167 or BMS-378806 to inhibit infection of cell lines. In vivo, significant protection was achieved using each compound alone and in combinations. CMPD167 and BMS-378806 were protective even when applied 6 h before challenge.

  1. Inter-α inhibitor protein and its associated glycosaminoglycans protect against histone-induced injury.

    PubMed

    Chaaban, Hala; Keshari, Ravi S; Silasi-Mansat, Robert; Popescu, Narcis I; Mehta-D'Souza, Padmaja; Lim, Yow-Pin; Lupu, Florea

    2015-04-02

    Extracellular histones are mediators of tissue injury and organ dysfunction; therefore they constitute potential therapeutic targets in sepsis, inflammation, and thrombosis. Histone cytotoxicity in vitro decreases in the presence of plasma. Here, we demonstrate that plasma inter-α inhibitor protein (IAIP) neutralizes the cytotoxic effects of histones and decreases histone-induced platelet aggregation. These effects are mediated through the negatively charged glycosaminoglycans (GAGs) chondroitin sulfate and high-molecular-weight hyaluronan (HMW-HA) associated with IAIP. Cell surface anionic glycosaminoglycans heparan sulfate and HA protect the cells against histone-mediated damage in vitro. Surface plasmon resonance showed that both IAIP and HMW-HA directly bind to recombinant histone H4. In vivo neutralization of histones with IAIP and HMW-HA prevented histone-induced thrombocytopenia, bleeding, and lung microvascular thrombosis, decreased neutrophil activation, and averted histone-induced production of inflammatory cytokines and chemokines. IAIP and HMW-HA colocalized with histones in necrotic tissues and areas that displayed neutrophil extracellular traps. Increasing amounts of IAIP-histone complexes detected in the plasma of septic baboons correlated with increase in histones and/or nucleosomes and consumption of plasma IAIP. Our data suggest that IAIP, chondroitin sulfate, and HMW-HA are potential therapeutic agents to protect against histone-induced cytotoxicity, coagulopathy, systemic inflammation, and organ damage during inflammatory conditions such as sepsis and trauma.

  2. Use of Mesothelial Cells and Biological Matrices for Tissue Engineering of Simple Epithelium Surrogates

    PubMed Central

    Lachaud, Christian Claude; Rodriguez-Campins, Berta; Hmadcha, Abdelkrim; Soria, Bernat

    2015-01-01

    Tissue-engineering technologies have progressed rapidly through last decades resulting in the manufacture of quite complex bioartificial tissues with potential use for human organ and tissue regeneration. The manufacture of avascular monolayered tissues such as simple squamous epithelia was initiated a few decades ago and is attracting increasing interest. Their relative morphostructural simplicity makes of their biomimetization a goal, which is currently accessible. The mesothelium is a simple squamous epithelium in nature and is the monolayered tissue lining the walls of large celomic cavities (peritoneal, pericardial, and pleural) and internal organs housed inside. Interestingly, mesothelial cells can be harvested in clinically relevant numbers from several anatomical sources and not less important, they also display high transdifferentiation capacities and are low immunogenic characteristics, which endow these cells with therapeutic interest. Their combination with a suitable scaffold (biocompatible, degradable, and non-immunogenic) may allow the manufacture of tailored serosal membranes biomimetics with potential spanning a wide range of therapeutic applications, principally for the regeneration of simple squamous-like epithelia such as the visceral and parietal mesothelium vascular endothelium and corneal endothelium among others. Herein, we review recent research progresses in mesothelial cells biology and their clinical sources. We make a particular emphasis on reviewing the different types of biological scaffolds suitable for the manufacture of serosal mesothelial membranes biomimetics. Finally, we also review progresses made in mesothelial cells-based therapeutic applications and propose some possible future directions. PMID:26347862

  3. Vitronectin adsorption to chrysotile asbestos increases fiber phagocytosis and toxicity for mesothelial cells.

    PubMed

    Wu, J; Liu, W; Koenig, K; Idell, S; Broaddus, V C

    2000-11-01

    Biological modification of asbestos fibers can alter their interaction with target cells. We have shown that vitronectin (VN), a major adhesive protein in serum, adsorbs to crocidolite asbestos and increases fiber phagocytosis by mesothelial cells via integrins. Because chrysotile asbestos differs significantly from crocidolite in charge and shape, we asked whether VN would also adsorb to chrysotile asbestos and increase its toxicity for mesothelial cells. We found that VN, either from purified solutions or from serum, adsorbed to chrysotile but at a lower amount per surface area than to crocidolite. Nevertheless, VN coating increased the phagocytosis of chrysotile as well as of crocidolite asbestos. VN coating of both chrysotile and crocidolite, but not of glass beads, increased intracellular oxidation and apoptosis of mesothelial cells. The additional apoptosis could be blocked by integrin-ligand blockade with arginine-glycine-aspartic acid peptides, confirming a role for integrins in the fiber-induced toxicity. We conclude that VN increases the phagocytosis of chrysotile as well as of crocidolite asbestos and that phagocytosis is important in fiber-induced toxicity for mesothelial cells.

  4. C1-Inhibitor protects from focal brain trauma in a cortical cryolesion mice model by reducing thrombo-inflammation.

    PubMed

    Albert-Weissenberger, Christiane; Mencl, Stine; Schuhmann, Michael K; Salur, Irmak; Göb, Eva; Langhauser, Friederike; Hopp, Sarah; Hennig, Nelli; Meuth, Sven G; Nolte, Marc W; Sirén, Anna-Leena; Kleinschnitz, Christoph

    2014-01-01

    Traumatic brain injury (TBI) induces a strong inflammatory response which includes blood-brain barrier damage, edema formation and infiltration of different immune cell subsets. More recently, microvascular thrombosis has been identified as another pathophysiological feature of TBI. The contact-kinin system represents an interface between inflammatory and thrombotic circuits and is activated in different neurological diseases. C1-Inhibitor counteracts activation of the contact-kinin system at multiple levels. We investigated the therapeutic potential of C1-Inhibitor in a model of TBI. Male and female C57BL/6 mice were subjected to cortical cryolesion and treated with C1-Inhibitor after 1 h. Lesion volumes were assessed between day 1 and day 5 and blood-brain barrier damage, thrombus formation as well as the local inflammatory response were determined post TBI. Treatment of male mice with 15.0 IU C1-Inhibitor, but not 7.5 IU, 1 h after cryolesion reduced lesion volumes by ~75% on day 1. This protective effect was preserved in female mice and at later stages of trauma. Mechanistically, C1-Inhibitor stabilized the blood-brain barrier and decreased the invasion of immune cells into the brain parenchyma. Moreover, C1-Inhibitor had strong antithrombotic effects. C1-Inhibitor represents a multifaceted anti-inflammatory and antithrombotic compound that prevents traumatic neurodegeneration in clinically meaningful settings.

  5. Ovarian cancer ascites enhance the migration of patient-derived peritoneal mesothelial cells via cMet pathway through HGF-dependent and -independent mechanisms.

    PubMed

    Matte, Isabelle; Lane, Denis; Laplante, Claude; Garde-Granger, Perrine; Rancourt, Claudine; Piché, Alain

    2015-07-15

    Ovarian cancer ascites consist of a proinflammatory environment that is characterized by the presence of abundant human peritoneal mesothelial cells (HPMCs). Cytokines and growth factors in ascites modulate cell activities of tumor cells. The expression of proinflammatory cytokines in ascites is associated with a more aggressive tumor phenotype. The effect of ascites on HPMCs is for the most part unknown but this interplay is thought to be important for epithelial ovarian cancer (EOC) progression. Here, we examine the components of ascites, which stimulate patient-derived HPMC migration, from women with advanced EOC. We show that ovarian cancer ascites enhanced the migration of HPMCs. This effect was inhibited by heat treatment, hepatocyte growth factor (HGF) blocking antibodies and a HGF receptor (cMet) inhibitor. In ovarian cancer ascites, HGF is present at high concentration compared to benign fluids. Ascites-mediated activation of cMet was associated with Akt and EKR1/2 phosphorylation. This response was partly inhibited by heat treatment and cMet inhibitor. Ascites-induced migration and a cMet phosphorylation were strongly inhibited by epidermal growth factor receptor (EGFR) inhibitor PD153035, suggesting the transactivation of cMet by EGFR. Our study suggests that HGF and ligands of EGFR are factors that mediate ovarian cancer ascites-mediated migration of HPMCs by activating cMet and possibly downstream ERK1/2 and Akt pathways. The study provides evidence for the first time that ascites not only support tumor growth but also enhance the migratory potential of cancer-associated mesothelial cells, which in turn may support cancer progression.

  6. C1 inhibitor-mediated myocardial protection from chronic intermittent hypoxia-induced injury

    PubMed Central

    Fu, Jinrong; Guo, Furong; Chen, Cheng; Yu, Xiaoman; Hu, Ke; Li, Mingjiang

    2016-01-01

    The optimal treatment for chronic intermittent hypoxia (CIH)-induced cardiovascular injuries has yet to be determined. The aim of the current study was to explore the potential protective effect and mechanism of a C1 inhibitor in CIH in the myocardium. The present study used a rat model of CIH in which complement regulatory protein, known as C1 inhibitor (C1INH), was administered to the rats in the intervention groups. Cardiomyocyte apoptosis was detected by terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling. The expression of proteins associated with the apoptotic pathway, such as B-cell lymphoma 2 (Bcl-2), Bax and caspase-3 were detected by western blot analysis. The expression of complement C3 protein and RNA were also analyzed. C1INH was observed to improve the cardiac function in rats with CIH. Myocardial myeloperoxidase activity, a marker of neutrophil infiltration, was significantly decreased in the C1INH intervention group compared with the CIH control group, and cardiomyocyte apoptosis was significantly attenuated (P<0.05). Western blotting and reverse transcription-polymerase chain reaction analysis indicated that the protein expression levels of Bcl-2 were decreased and those of Bax were increased in the CIH group compared with the normal control group, but the protein expression levels of Bcl-2 were increased and those of Bax were decreased in the C1INH intervention group, as compared with the CIH group. Furthermore, the CIH-induced expression and synthesis of complement C3 in the myocardium were also reduced in the C1INH intervention group. C1INH, in addition to inhibiting complement activation and inflammation, preserved cardiac function in CIH-mediated myocardial cell injury through an anti-apoptotic mechanism. PMID:27698713

  7. Alterations in gene expression in human mesothelial cells correlate with mineral pathogenicity.

    PubMed

    Shukla, Arti; MacPherson, Maximilian B; Hillegass, Jedd; Ramos-Nino, Maria E; Alexeeva, Vlada; Vacek, Pamela M; Bond, Jeffrey P; Pass, Harvey I; Steele, Chad; Mossman, Brooke T

    2009-07-01

    Human mesothelial cells (LP9/TERT-1) were exposed to low and high (15 and 75 microm(2)/cm(2) dish) equal surface area concentrations of crocidolite asbestos, nonfibrous talc, fine titanium dioxide (TiO2), or glass beads for 8 or 24 hours. RNA was then isolated for Affymetrix microarrays, GeneSifter analysis and QRT-PCR. Gene changes by asbestos were concentration- and time-dependent. At low nontoxic concentrations, asbestos caused significant changes in mRNA expression of 29 genes at 8 hours and of 205 genes at 24 hours, whereas changes in mRNA levels of 236 genes occurred in cells exposed to high concentrations of asbestos for 8 hours. Human primary pleural mesothelial cells also showed the same patterns of increased gene expression by asbestos. Nonfibrous talc at low concentrations in LP9/TERT-1 mesothelial cells caused increased expression of 1 gene Activating Transcription Factor 3 (ATF3) at 8 hours and no changes at 24 hours, whereas expression levels of 30 genes were elevated at 8 hours at high talc concentrations. Fine TiO2 or glass beads caused no changes in gene expression. In human ovarian epithelial (IOSE) cells, asbestos at high concentrations elevated expression of two genes (NR4A2, MIP2) at 8 hours and 16 genes at 24 hours that were distinct from those elevated in mesothelial cells. Since ATF3 was the most highly expressed gene by asbestos, its functional importance in cytokine production by LP9/TERT-1 cells was assessed using siRNA approaches. Results reveal that ATF3 modulates production of inflammatory cytokines (IL-1 beta, IL-13, G-CSF) and growth factors (VEGF and PDGF-BB) in human mesothelial cells.

  8. Neutrophil and asbestos fiber-induced cytotoxicity in cultured human mesothelial and bronchial epithelial cells.

    PubMed

    Kinnula, V L; Raivio, K O; Linnainmaa, K; Ekman, A; Klockars, M

    1995-03-01

    This study investigates reactive oxygen species generation and oxidant-related cytotoxicity induced by amosite asbestos fibers and polymorphonuclear leucocytes (PMNs) in human mesothelial cells and human bronchial epithelial cells in vitro. Transformed human pleural mesothelial cells (MET 5A) and bronchial epithelial cells (BEAS 2B) were treated with amosite (2 micrograms/cm2) for 48 h. After 24 h of incubation, the cells were exposed for 1 h to nonactivated or amosite (50 micrograms) activated PMNs, washed, and incubated for another 23 h. Reactive oxygen species generation by the PMNs and the target cells was measured by chemiluminescence. Cell injury was assessed by cellular adenine nucleotide depletion, extracellular release of nucleotides, and lactate dehydrogenase (LDH). Amosite-activated (but also to a lesser degree nonactivated) PMNs released substantial amounts of reactive oxygen metabolites, whereas the chemiluminescence of amosite-exposed mesothelial cells and epithelial cells did not differ from the background. Amosite treatment (48 h) of the target cells did not change intracellular adenine nucleotides (ATP, ADP, AMP) or nucleotide catabolite products (xanthine, hypoxanthine, and uric acid). When the target cells were exposed to nonactivated PMNs, significant adenine nucleotide depletion and nucleotide catabolite accumulation was observed in mesothelial cells only. In separate experiments, when the target cells were exposed to amosite-activated PMNs, the target cell injury was further potentiated compared with the amosite treatment alone or exposure to nonactivated PMNs. In conclusion, this study suggests the importance of inflammatory cell-derived free radicals in the development of amosite-induced mesothelial cell injury.

  9. Role of renin angiotensin system inhibitors in cardiovascular and renal protection: a lesson from clinical trials.

    PubMed

    Stojiljkovic, Ljuba; Behnia, Rahim

    2007-01-01

    Beneficial effects of angiotensin converting enzyme inhibitors (ACEI) and angiotensin type 1 receptor (AT1) blockers in patients with cardiovascular and renal diseases have been clearly demonstrated in numerous large outcomes studies. In patients with heart failure (HF), ACEI have been shown to reduce overall mortality, mortality from cardiovascular causes, to increase life expectancy, as well as to preserve the renal function (CONSENSUS, SAVE, TRACE, AIRE, AIREX, CATS trials). In addition, in the PROGRESS study ACEI substantially decreased the risk of stroke and transient ischemic attacks in patients with cerebrovascular disorders. The HOPE and EUROPA studies confirmed that long term therapy with ACEI provides significant survival benefit in patients with broad range of atherosclerotic cardiovascular diseases. After these large and well designed clinical studies, ACEI have become standard therapy for routine secondary prevention in all patients with cardiovascular diseases, unless contraindicated. AT1 receptor blockers have been recently added to the cardiovascular therapeutic armamentarium. They are believed to provide additional protection by inhibition of locally synthesized angiotensin II on the level of AT1 receptor. The ELITE II, ValHeFT and CHARM studies have shown that AT1 receptor blockers are equally effective as ACEI in reduction of mortality and morbidity in patients with HF. Importantly, they may be used together with ACEI, or as alternative treatment in ACEI intolerant patients. Renal protection is another important effect of both ACEI and AT1 blockers that has been confirmed in several large clinical trials. The North American Microalbuminemia Study group and EUCLID group demonstrated significant reduction in progression of diabetic nephropathy in patients with insulin dependent diabetes mellitus (IDDM) treated with ACEI. AT1 receptor blockers are mainly studied in the non-insulin dependent diabetes mellitus (NIDDM) nephropathy. Four recent clinical

  10. ADMINISTRATION OF A SUBSTITUTED ADAMANTLY-UREA INHIBITOR OF THE SOLUBLE EPOXIDE HYDROLASE PROTECTS THE KIDNEY FROM DAMAGE IN HYPERTENSIVE GOTO-KAKIZAKI RATS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Hypertension and type II diabetes are co-morbid diseases that lead to the development of nephropathy. Soluble epoxide hydrolase (sEH) inhibitors are reported to provide protection from renal injury. We hypothesized that the sEH inhibitor 12-(3-adamantan-1-yl-ureido) dodecanoic acid (AUDA) protects ...

  11. Ectromelia virus inhibitor of complement enzymes protects intracellular mature virus and infected cells from mouse complement.

    PubMed

    Moulton, Elizabeth A; Bertram, Paula; Chen, Nanhai; Buller, R Mark L; Atkinson, John P

    2010-09-01

    Poxviruses produce complement regulatory proteins to subvert the host's immune response. Similar to the human pathogen variola virus, ectromelia virus has a limited host range and provides a mouse model where the virus and the host's immune response have coevolved. We previously demonstrated that multiple components (C3, C4, and factor B) of the classical and alternative pathways are required to survive ectromelia virus infection. Complement's role in the innate and adaptive immune responses likely drove the evolution of a virus-encoded virulence factor that regulates complement activation. In this study, we characterized the ectromelia virus inhibitor of complement enzymes (EMICE). Recombinant EMICE regulated complement activation on the surface of CHO cells, and it protected complement-sensitive intracellular mature virions (IMV) from neutralization in vitro. It accomplished this by serving as a cofactor for the inactivation of C3b and C4b and by dissociating the catalytic domain of the classical pathway C3 convertase. Infected murine cells initiated synthesis of EMICE within 4 to 6 h postinoculation. The levels were sufficient in the supernatant to protect the IMV, upon release, from complement-mediated neutralization. EMICE on the surface of infected murine cells also reduced complement activation by the alternative pathway. In contrast, classical pathway activation by high-titer antibody overwhelmed EMICE's regulatory capacity. These results suggest that EMICE's role is early during infection when it counteracts the innate immune response. In summary, ectromelia virus produced EMICE within a few hours of an infection, and EMICE in turn decreased complement activation on IMV and infected cells.

  12. The long-acting integrase inhibitor GSK744 protects macaques from repeated intravaginal SHIV challenge.

    PubMed

    Radzio, Jessica; Spreen, William; Yueh, Yun Lan; Mitchell, James; Jenkins, Leecresia; García-Lerma, J Gerardo; Heneine, Walid

    2015-01-14

    Daily preexposure prophylaxis (PrEP) with Truvada is a proven HIV prevention strategy; however, its effectiveness is limited by low adherence. Antiretroviral drug formulations that require infrequent dosing may increase adherence and thus PrEP effectiveness. We investigated whether monthly injections of a long-acting formulation of the HIV integrase inhibitor GSK1265744 (GSK744 LA) prevented simian/human immunodeficiency virus (SHIV) infection by vaginal challenge in macaques. Female pigtail macaques (n = 12) were exposed to intravaginal inoculations of SHIV twice a week for up to 11 weeks. Half of the animals received a GSK744 LA injection every 4 weeks, and half received placebo. GSK744 LA, at plasma concentrations achievable with quarterly injections in humans, protected all six macaques from infection. Placebo controls were all infected after a median of 4 (range, 2 to 20) vaginal challenges with SHIV. Efficacy was related to high and sustained vaginal and plasma drug concentrations that remained above the protein-adjusted 90% inhibitory concentration during the dosing cycles. These data support advancement of GSK744 LA as a potential PrEP candidate for women.

  13. Epidermal growth factor receptor inhibitor protects against abdominal aortic aneurysm in a mouse model.

    PubMed

    Obama, Takashi; Tsuji, Toshiyuki; Kobayashi, Tomonori; Fukuda, Yamato; Takayanagi, Takehiko; Taro, Yoshinori; Kawai, Tatsuo; Forrester, Steven J; Elliott, Katherine J; Choi, Eric; Daugherty, Alan; Rizzo, Victor; Eguchi, Satoru

    2015-05-01

    Angiotensin II (Ang II) has been implicated in the development of abdominal aortic aneurysm (AAA). In vascular smooth muscle cells (VSMC), Ang II activates epidermal growth factor receptor (EGFR) mediating growth promotion. We hypothesized that inhibition of EGFR prevents Ang II-dependent AAA. C57BL/6 mice were co-treated with Ang II and β-aminopropionitrile (BAPN) to induce AAA with or without treatment with EGFR inhibitor, erlotinib. Without erlotinib, 64.3% of mice were dead due to aortic rupture. All surviving mice had AAA associated with EGFR activation. Erlotinib-treated mice did not die and developed far fewer AAA. The maximum diameters of abdominal aortas were significantly shorter with erlotinib treatment. In contrast, both erlotinib-treated and non-treated mice developed hypertension. The erlotinib treatment of abdominal aorta was associated with lack of EGFR activation, endoplasmic reticulum (ER) stress, oxidative stress, interleukin-6 induction and matrix deposition. EGFR activation in AAA was also observed in humans. In conclusion, EGFR inhibition appears to protect mice from AAA formation induced by Ang II plus BAPN. The mechanism seems to involve suppression of vascular EGFR and ER stress.

  14. Bifunctional apoptosis inhibitor (BAR) protects neurons from diverse cell death pathways.

    PubMed

    Roth, W; Kermer, P; Krajewska, M; Welsh, K; Davis, S; Krajewski, S; Reed, J C

    2003-10-01

    The bifunctional apoptosis regulator (BAR) is a multidomain protein that was originally identified as an inhibitor of Bax-induced apoptosis. Immunoblot analysis of normal human tissues demonstrated high BAR expression in the brain, compared to low or absent expression in other organs. Immunohistochemical staining of human adult tissues revealed that the BAR protein is predominantly expressed by neurons in the central nervous system. Immunofluorescence microscopy indicated that BAR localizes mainly to the endoplasmic reticulum (ER) of cells. Overexpression of BAR in CSM 14.1 neuronal cells resulted in significant protection from a broad range of cell death stimuli, including agents that activate apoptotic pathways involving mitochondria, TNF-family death receptors, and ER stress. Downregulation of BAR by antisense oligonucleotides sensitized neuronal cells to induction of apoptosis. Moreover, the search for novel interaction partners of BAR identified several candidate proteins that might contribute to the regulation of neuronal apoptosis (HIP1, Hippi, and Bap31). Taken together, the expression pattern and functional data suggest that the BAR protein is involved in the regulation of neuronal survival.

  15. Programmed necrosis induced by asbestos in human mesothelial cells causes high-mobility group box 1 protein release and resultant inflammation

    PubMed Central

    Yang, Haining; Rivera, Zeyana; Jube, Sandro; Nasu, Masaki; Bertino, Pietro; Goparaju, Chandra; Franzoso, Guido; Lotze, Michael T.; Krausz, Thomas; Pass, Harvey I.; Bianchi, Marco E.; Carbone, Michele

    2010-01-01

    Asbestos carcinogenesis has been linked to the release of cytokines and mutagenic reactive oxygen species (ROS) from inflammatory cells. Asbestos is cytotoxic to human mesothelial cells (HM), which appears counterintuitive for a carcinogen. We show that asbestos-induced HM cell death is a regulated form of necrosis that links to carcinogenesis. Asbestos-exposed HM activate poly(ADP-ribose) polymerase, secrete H2O2, deplete ATP, and translocate high-mobility group box 1 protein (HMGB1) from the nucleus to the cytoplasm, and into the extracellular space. The release of HMGB1 induces macrophages to secrete TNF-α, which protects HM from asbestos-induced cell death and triggers a chronic inflammatory response; both favor HM transformation. In both mice and hamsters injected with asbestos, HMGB1 was specifically detected in the nuclei, cytoplasm, and extracellular space of mesothelial and inflammatory cells around asbestos deposits. TNF-α was coexpressed in the same areas. HMGB1 levels in asbestos-exposed individuals were significantly higher than in nonexposed controls (P < 0.0001). Our findings identify the release of HMGB1 as a critical initial step in the pathogenesis of asbestos-related disease, and provide mechanistic links between asbestos-induced cell death, chronic inflammation, and carcinogenesis. Chemopreventive approaches aimed at inhibiting the chronic inflammatory response, and especially blocking HMGB1, may decrease the risk of malignant mesothelioma among asbestos-exposed cohorts. PMID:20616036

  16. Mdm2 inhibition confers protection of p53-proficient cells from the cytotoxic effects of Wee1 inhibitors.

    PubMed

    Li, Yizhu; Saini, Priyanka; Sriraman, Anusha; Dobbelstein, Matthias

    2015-10-20

    Pharmacological inhibition of the cell cycle regulatory kinase Wee1 represents a promising strategy to eliminate cancer cells. Wee1 inhibitors cooperate with chemotherapeutics, e. g. nucleoside analogues, pushing malignant cells from S phase towards premature mitosis and death. However, considerable toxicities are observed in preclinical and clinical trials. A high proportion of tumor cells can be distinguished from all other cells of a patient's body by inactivating mutations in the tumor suppressor p53. Here we set out to develop an approach for the selective protection of p53-proficient cells against the cytotoxic effects of Wee1 inhibitors. We pretreated such cells with Nutlin-3a, a prototype inhibitor of the p53-antagonist Mdm2. The resulting transient cell cycle arrest effectively increased the survival of cells that were subsequently treated with combinations of the Wee1 inhibitor MK-1775 and/or the nucleoside analogue gemcitabine. In this constellation, Nutlin-3a reduced caspase activation and diminished the phosphorylation of Histone 2AX, an indicator of the DNA damage response. Both effects were strictly dependent on the presence of p53. Moreover, Nutlin pre-treatment reduced the fraction of cells that were undergoing premature mitosis in response to Wee1 inhibition. We conclude that the pre-activation of p53 through Mdm2 antagonists serves as a viable option to selectively protect p53-proficient cells against the cytotoxic effects of Wee1 inhibitors, especially when combined with a nucleoside analogue. Thus, Mdm2 antagonists might prove useful to avoid unwanted side effects of Wee1 inhibitors. On the other hand, when a tumor contains wild type p53, care should be taken not to induce its activity before applying Wee1 inhibitors.

  17. Unscheduled DNA synthesis in rat pleural mesothelial cells treated with mineral fibres.

    PubMed

    Renier, A; Lévy, F; Pillière, F; Jaurand, M C

    1990-08-01

    Unscheduled DNA synthesis (UDS) was studied in confluent rat pleural mesothelial cells (RPMCs) arrested in G0/G1 with hydroxyurea (HU) and treated with various fibre types, i.e., chrysotile, crocidolite or attapulgite. In addition, the effects of UV light and of benzo[a]pyrene were determined as references. Using autoradiography after [3H]thymidine incorporation ([3H]dThd), RPMCs treated with 4 micrograms/cm2 of chrysotile fibres exhibited a low but significant enhancement of net grains compared to untreated cells. Treatment with higher doses of chrysotile was not possible because of the impairment of microscopic observation due to the presence of the fibres. Using liquid scintillation counting, RPMCs treated with chrysotile or crocidolite showed a significant dose-dependent increase in [3H]dThd incorporation compared to untreated cells. In contrast, attapulgite did not enhance [3H]dThd incorporation compared to untreated cells. Treatment of RPMCs with 1, 2 or 4 micrograms/ml of benzo[a]pyrene resulted in a significant increase in [3H]dThd incorporation. In order to discount a possible role of S cells in the augmentation of [3H]dThd incorporation, despite the presence of 5 mM HU, S cells were counted by autoradiography. Results indicated that the percentage of S cells was similar in asbestos-treated and untreated cultures. Stimulation of the S phase also seems unlikely because treatment of RPMCs with asbestos fibres in the absence of HU resulted in a reduction of [3H]dThd incorporation attributed to an impairment of the S phase by the fibres. 1-4 micrograms/ml benzo[a]pyrene or 10-50 J/m2 UV light resulted in an approximate doubling of [3H]dThd incorporation. The effects of inhibitors of DNA repair were determined in chrysotile-treated RPMCs. [3H]dThd incorporation was inhibited by cytosine arabinoside and nalidixic acid. These results show that asbestos produces UDS in RPMCs.

  18. Statins and Renin Angiotensin System Inhibitors Dose-Dependently Protect Hypertensive Patients against Dialysis Risk

    PubMed Central

    Wu, Szu-Yuan

    2016-01-01

    Background Taiwan has the highest renal disease incidence and prevalence in the world. We evaluated the association of statin and renin–angiotensin system inhibitor (RASI) use with dialysis risk in hypertensive patients. Methods Of 248,797 patients who received a hypertension diagnosis in Taiwan during 2001–2012, our cohort contained 110,829 hypertensive patients: 44,764 who used RASIs alone; 7,606 who used statins alone; 27,836 who used both RASIs and statins; and 33,716 who used neither RASIs or statins. We adjusted for the following factors to reduce selection bias by using propensity scores (PSs): age; sex; comorbidities; urbanization level; monthly income; and use of nonstatin lipid-lowering drugs, metformin, aspirin, antihypertensives, diuretics, and beta and calcium channel blockers. The statin and RASI use index dates were considered the hypertension confirmation dates. To examine the dose–response relationship, we categorized only statin or RASI use into four groups in each cohort: <28 (nonusers), 28–90, 91–365, and >365 cumulative defined daily doses (cDDDs). Results In the main model, PS-adjusted hazard ratios (aHRs; 95% confidence intervals [CIs]) for dialysis risk were 0.57 (0.50–0.65), 0.72 (0.53–0.98), and 0.47 (0.41–0.54) in the only RASI, only statin, and RASI + statin users, respectively. RASIs dose-dependently reduced dialysis risk in most subgroups and in the main model. RASI use significantly reduced dialysis risk in most subgroups, regardless of comorbidities or other drug use (P < 0.001). Statins at >365 cDDDs protected hypertensive patients against dialysis risk in the main model (aHR = 0.62, 95% CI: 0.54–0.71), regardless of whether a high cDDD of RASIs, metformin, or aspirin was used. Conclusion Statins and RASIs independently have a significant dose-dependent protective effect against dialysis risk in hypertensive patients. The combination of statins and RASIs can additively protect hypertensive patients against dialysis

  19. A new dioxime corrosion inhibitor for the protection and conservation of copper: synthesis, characterization and evaluation in acidic chloride solution

    NASA Astrophysics Data System (ADS)

    Abu-Baker, Ahmad N.; Al-Qudah, Mahmoud A.

    2016-08-01

    This study aimed to investigate a new dioxime compound as a corrosion inhibitor for copper. The compound (4,6-dihydroxy benzene-1,3-dicarbaldehyde dioxime) was synthesized and characterized by nuclear magnetic resonance spectroscopy. Electrochemical impedance spectroscopy and potentiodynamic polarization measurements were used to compare the dioxime compound with benzotriazole for their effectiveness as corrosion inhibitors for copper in 0.1 M HCl solution. Fourier transform infrared (FTIR) spectroscopy and scanning electron microscopy (SEM) were used to investigate the bonding mechanisms and morphological changes of the two inhibitors on the copper surface. The electrochemical techniques showed that the new dioxime compound was more effective than benzotriazole in inhibiting copper corrosion in the acidic chloride medium. The FTIR and SEM results indicated that the dioxime compound was able to coordinate with copper ions and formed a protective film on the copper surface. It was concluded that the new dioxime compound proved effectiveness to be used as a corrosion inhibitor for the protection and conservation of copper.

  20. High-glucose-based peritoneal dialysis solution induces the upregulation of VEGF expression in human peritoneal mesothelial cells: The role of pleiotrophin.

    PubMed

    Liu, Jia; Wu, Xia; Liu, Yanchun; Xu, Yaguang; Huang, Yuhan; Xing, Changying; Wang, Xiaoyun

    2013-11-01

    The aim of the present study was to investigate the effect of a high-glucose-based peritoneal dialysis solution (HGPDS) on the expression of pleiotrophin (PTN) and vascular endothelial growth factor (VEGF) in human peritoneal mesothelial cells (HPMCs) and the mechanisms through which fluvastatin (Flu) protects the peritoneal membrane in continuous ambulatory peritoneal dialysis (CAPD). HPMCs were cultured with HGPDS, Flu (10-8‑10-6 mol/l) and PTN (10‑30 nmol/l). The expression of PTN and VEGF was examined at the mRNA and protein level. To define the role of PTN in the regulation of VEGF expression, HPMCs were cultured with HGPDS in the presence or absence of the blocking peptide of PTN. The signaling pathways involved in PTN synthesis induced by HGPDS were also characterized. The phenotypic characteristics of HPMCs were observed under a light microscope. Cell viability was measured by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) colorimetry and the mRNA and protein expression of PTN, VEGF and ERK1/2 was assessed by RT‑PCR and the western blot analysis, respectively. Following incubation with HGPDS for 48 h, the morphology of the HPMCs changed from a typical cobblestone‑like appearance to a fibroblast‑like phenotype. The same alteration in the morphology of the HPMCs also occurred following incubation with 20 nmol/l PTN. Flu (10-6 mol/l), GSK650394 [a competitive inhibitor of serum/glucocorticoid-regulated kinase 1 (SGK1), 10-5 mol/l] and PD98059 (a competitive inhibitor of ERK1/2, 10-5 mol/l) improved the negative changes in cell morphology induced by HGPDS. The results of MTT assay revealed that the reduction in HPMC viability occurred in the groups treated with HGPDS and this reduction was partially restored by Flu, GSK650394 and PD98059. A significant improvement in cell viability, which had been decreased by HGPDS, was observed following treatment with Flu (10-6 mol/l), PD98059 (10-5 mol/l) or GSK650394 (10-5 mol/l) (P<0

  1. Expression and regulation of epithelial Na+ channels by nucleotides in pleural mesothelial cells.

    PubMed

    Nie, Hong-Guang; Tucker, Torry; Su, Xue-Feng; Na, Tao; Peng, Ji-Bin; Smith, Peter R; Idell, Steven; Ji, Hong-Long

    2009-05-01

    Pleural effusions are commonly clinical disorders, resulting from the imbalance between pleural fluid turnover and reabsorption. The mechanisms underlying pleural fluid clearance across the mesothelium remain to be elucidated. We hypothesized that epithelial Na(+) channel (ENaC) is expressed and forms the molecular basis of the amiloride-sensitive resistance in human mesothelial cells. Our RT-PCR results showed that three ENaC subunits, namely, alpha, beta, gamma, and two delta ENaC subunits, are expressed in human primary pleural mesothelial cells, a human mesothelioma cell line (M9K), and mouse pleural tissue. In addition, Western blotting and immunofluorescence microscopy studies revealed that alpha, beta, gamma, and delta ENaC subunits are expressed in primary human mesothelial cells and M9K cells at the protein level. An amiloride-inhibitable short-circuit current was detected in M9K monolayers and mouse pleural tissues when mounted in Ussing chambers. Whole-cell patch clamp recordings showed an ENaC-like channel with an amiloride concentration producing 50% inhibition of 12 microM in M9K cells. This cation channel has a high affinity for extracellular Na+ ions (K(m): 53 mM). The ion selectivity of this channel to cations follows the same order as ENaC: Li+ > Na+ > K+. The unitary Li(+) conductance was 15 pS in on-cell patches. Four ENaC subunits form a functional Na+ channel when coinjected into Xenopus oocytes. Furthermore, we found that both forskolin and cGMP increased the short-circuit currents in mouse pleural tissues. Taken together, our data demonstrate that the ENaC channels are biochemically and functionally expressed in human pleural mesothelial cells, and can be up-regulated by cyclic AMP and cyclic GMP.

  2. Mesothelial cell proliferation after instillation of long or short asbestos fibers into mouse lung.

    PubMed Central

    Adamson, I. Y.; Bakowska, J.; Bowden, D. H.

    1993-01-01

    The relationship of asbestos deposition in the lung to subsequent cell proliferation at the pleural surface is not clear. The present study examines DNA synthesis by various pulmonary cells, particularly those at the pleura after intratracheal injection of 0.1 mg crocidolite to mice using: 1) long fibers (> 20 mu), which are deposited in bronchiolar regions and induce fibrosis; 2) short fibers (< 1 mu), which reach alveoli but do not induce fibrosis. Mice also received 2 microCi/g tritiated thymidine 1 hour before death at intervals to 16 weeks. Short fibers induced only a small increase in labeling of bronchiolar epithelial and interstitial cells, which subsided by 5 days, when a small increase in labeled mesothelial and subpleural cells was seen. In contrast, long fibers damaged the bronchiolar epithelium and became incorporated into connective tissue. During regeneration, 12% of cells were labeled at 3 days and labeling was greater than controls to 4 weeks. Increased peribronchiolar labeling of fibroblasts and interstitial macrophages was seen around long fibers, and increased DNA synthesis by mesothelial and subpleural cells was found. Up to 2% of mesothelial cells were labeled 1 week after long fibers compared to near zero in controls. No long fibers were found at the pleura. Activation of interstitial macrophages in response to long crocidolite fibers is associated with fibroblast proliferation. It is now suggested that mesothelial cells may also be stimulated by cytokines from activated interstitial macrophages that diffuse across the interstitium, without requiring actual fiber translocation to the pleura. Images Figure 1 Figure 2 Figure 3 Figure 6 Figure 9 Figure 11 PMID:8475994

  3. Effects of cigarette smoke and asbestos on airway, vascular and mesothelial cell proliferation.

    PubMed Central

    Sekhon, H.; Wright, J.; Churg, A.

    1995-01-01

    In order to determine whether exposure to both cigarette smoke and asbestos leads to enhanced cell proliferation, and whether pleura cell proliferation reflects the presence of fibres at or near the pleura, rats were exposed to air (control), daily cigarette smoke, a single intratracheal instillation of amosite asbestos, or a combination of smoke and asbestos. Dividing cells were labelled with bromodeoxyuridine (BrdU) and animals were sacrificed at 1, 2, 7 or 14 days. Both cigarette smoke and asbestos produced increases in the labelling index of small airway wall, epithelial cells and pulmonary artery cells. In the small airways there was a brief marked positive synergistic interaction between these two agents, but synergism was not seen in the vessels. Cigarette smoke did not increase the labelling of mesothelial or submesothelial cells, whereas asbestos caused a persisting increase in mesothelial cell labelling. There was no correlation between the number of BrdU labelled mesothelial or submesothelial cells and the number of fibres touching the pleura, or located within 180 microns of the pleura. We conclude that the combination of cigarette smoke and asbestos exposure produces a complex set of interactions and has the potential to markedly increase cell proliferation in the parenchyma, an effect that may be important in both fibrogenesis and carcinogenesis. In contrast to the diminishing effects over time of a single dose of asbestos on cell proliferation in the small airways and vessels, the same dose of asbestos leads to sustained mesothelial cell proliferation. However, the latter process does not correlate with local accumulation of asbestos fibres. Images Figure 1 PMID:8652361

  4. Prolonged effect of fluid flow stress on the proliferative activity of mesothelial cells after abrupt discontinuation of fluid streaming

    SciTech Connect

    Aoki, Shigehisa; Ikeda, Satoshi; Takezawa, Toshiaki; Kishi, Tomoya; Makino, Junichi; Uchihashi, Kazuyoshi; Matsunobu, Aki; Noguchi, Mitsuru; Sugihara, Hajime; Toda, Shuji

    2011-12-16

    Highlights: Black-Right-Pointing-Pointer Late-onset peritoneal fibrosis leading to EPS remains to be elucidated. Black-Right-Pointing-Pointer Fluid streaming is a potent factor for peritoneal fibrosis in PD. Black-Right-Pointing-Pointer We focused on the prolonged effect of fluid streaming on mesothelial cell kinetics. Black-Right-Pointing-Pointer A history of fluid streaming exposure promoted mesothelial proliferative activity. Black-Right-Pointing-Pointer We have thus identified a potent new factor for late-onset peritoneal fibrosis. -- Abstract: Encapsulating peritoneal sclerosis (EPS) often develops after transfer to hemodialysis and transplantation. Both termination of peritoneal dialysis (PD) and transplantation-related factors are risks implicated in post-PD development of EPS, but the precise mechanism of this late-onset peritoneal fibrosis remains to be elucidated. We previously demonstrated that fluid flow stress induced mesothelial proliferation and epithelial-mesenchymal transition via mitogen-activated protein kinase (MAPK) signaling. Therefore, we speculated that the prolonged bioactive effect of fluid flow stress may affect mesothelial cell kinetics after cessation of fluid streaming. To investigate how long mesothelial cells stay under the bioactive effect brought on by fluid flow stress after removal of the stress, we initially cultured mesothelial cells under fluid flow stress and then cultured the cells under static conditions. Mesothelial cells exposed to fluid flow stress for a certain time showed significantly high proliferative activity compared with static conditions after stoppage of fluid streaming. The expression levels of protein phosphatase 2A, which dephosphorylates MAPK, in mesothelial cells changed with time and showed a biphasic pattern that was dependent on the duration of exposure to fluid flow stress. There were no differences in the fluid flow stress-related bioactive effects on mesothelial cells once a certain time had passed

  5. A localized PCR inhibitor in a porcelain crab suggests a protective role

    PubMed Central

    El-Maklizi, Mahmoud A.; Ouf, Amged; Ferreira, Ari; Hedar, Shahyn

    2014-01-01

    A number of polymerase chain reaction (PCR) inhibitors have been identified from biological and environmental samples. By and large, such substances are treated as random nuisances and contaminants with alternate functions; their inhibitory effects on DNA replication being a coincidental property of their molecular structure. Here, we demonstrate the presence of a localized PCR inhibitor in the foregut of the porcelain crab Petrolisthes rufescens (Anomura: Porcellanidae) from the Red Sea. The inhibitor precluded amplification of 28s, 16s and 18s gene sequences effectively but lost activity at 10−2 dilutions from initial concentration. Heat treatment was ineffective in arresting inhibition and spectrophotometric techniques suggested that the inhibitor was not a melanin-type compound. The compound was not detected from midgut, hindgut, or gills of the crab. Activity of the inhibitor was precluded when samples were treated with suspensions from the midgut, suggesting that enzymatic degradation of the inhibitor likely happens at that part of the gut. As many microbial pathogens invade their hosts via ingestion, we suggest the presence of the localized inhibitor could carry a defensive or immunological role for P. rufescens. The identity of the inhibitory molecule remains unknown. PMID:25493214

  6. Platelet derived growth factor B and epithelial mesenchymal transition of peritoneal mesothelial cells.

    PubMed

    Patel, Pranali; West-Mays, Judy; Kolb, Martin; Rodrigues, Juan-Carlos; Hoff, Catherine M; Margetts, Peter J

    2010-03-01

    Platelet derived growth factor (PDGF) is involved in wound healing in various organ systems. Its potential role in the context of peritoneal injury following long-term peritoneal dialysis is unclear. We used an adenovirus expressing the B chain of PDGF (AdPDGF-B) to assess its effect on pro-fibrotic pathways in the peritoneal membrane. To assess the transforming growth factor (TGF) beta independent effects of PDGF, we over-expressed PDGF-B in the peritoneum of either wild-type mice (Smad3+/+) or those with a deletion of the TGFbeta signaling protein Smad3 (Smad3(-/-)). PDGF-B induced sustained angiogenesis in both Smad3+/+ and Smad3(-/-) mice. Despite increased collagen gene expression, collagen accumulation was transient and fibrogenesis was associated with induction of collagenase activity. We observed epithelial to mesenchymal transition (EMT) involving the peritoneal mesothelial cells, as shown by increased SNAIL and decreased E-Cadherin expression with evidence of mesothelial cells expressing both epithelial and mesenchymal markers. Unlike TGFbeta-induced EMT, PDGF-B exposure did not lead to mobilization of the mesothelial cells; they remained as a single monolayer throughout the observation period. This "non-invasive" EMT phenomenon is a novel finding and may have implications concerning the role of EMT in peritoneal fibrosis and injury to other organ systems. The observed effects were similar in Smad3(-/-) and Smad3+/+ animals, suggesting that the PDGF-B effects were independent of TGFbeta or Smad signaling.

  7. Stimulation of DNA synthesis in cultured primary human mesothelial cells by specific growth factors

    SciTech Connect

    Gabrielson, E.W.; Gerwin, B.I.; Harris, C.C.; Roberts, A.B.; Sporn, M.B.; Lechner, J.F.

    1988-08-01

    Monolayer cultures of human mesothelial cells made quiescent by serum deprivation are induced to undergo one round of DNA synthesis by platelet-derived growth factor (PDGF), epidermal growth factor (EGF), or transforming growth factor type beta 1 (TGF-beta 1). This one-time stimulation is independent of other serum components. The kinetics for induction of DNA synthesis observed for PDGF, EGF, and TGF-beta 1 are all similar to one another, with a peak of DNA synthesis occurring 24-36 h after the addition of the growth factors. Repetitive rounds of DNA synthesis and cell division do not ensue after addition of PDGF, EGF, or TGF-beta 1 alone or in combination; however, in media supplemented with chemically denatured serum, each of these factors is capable of sustaining continuous replication of mesothelial cells. Stimulation of growth by PDGF and TGF-beta 1 is unusual for an epithelial cell type, and indicates that mesothelial cells have growth regulatory properties similar to connective tissue cells.

  8. NFAT5 Contributes to Osmolality-Induced MCP-1 Expression in Mesothelial Cells

    PubMed Central

    Küper, Christoph; Beck, Franz-X.; Neuhofer, Wolfgang

    2012-01-01

    Increased expression of the C-C chemokine monocyte chemoattractant protein-1 (MCP-1) in mesothelial cells in response to high glucose concentrations and/or high osmolality plays a crucial role in the development of peritoneal fibrosis during continuous ambulatory peritoneal dialysis (CAPD). Recent studies suggest that in kidney cells osmolality-induced MCP-1 upregulation is mediated by the osmosensitive transcription factor, nuclear factor of activated T cells 5 (NFAT5). The present study addressed the question of whether activation of NFAT5 by hyperosmolality, as present in PD fluids, contributes to MCP-1 expression in the mesothelial cell line Met5A. Hyperosmolality, induced by addition of glucose, NaCl, or mannitol to the growth medium, increased NFAT5 activity and stimulated MCP-1 expression in Met5A cells. siRNA-mediated knockdown of NFAT5 attenuated osmolality-induced MCP-1 upregulation substantially. Hyperosmolality also induced activation of nuclear factor-κB (NF-κB). Accordingly, pharmacological inhibition of NF-κB significantly decreased osmolality-induced MCP-1 expression. Taken together, these results indicate that high osmolalities activate the transcription factor NFAT5 in mesothelial cells. NFAT5 in turn upregulates MCP-1, likely in combination with NF-κB, and thus may participate in the development of peritoneal fibrosis during CAPD. PMID:22619484

  9. An in-built proteinase inhibitor system for the protection of recombinant proteins recovered from transgenic plants.

    PubMed

    Rivard, Daniel; Anguenot, Raphaël; Brunelle, France; Le, Van Quy; Vézina, Louis-Philippe; Trépanier, Sonia; Michaud, Dominique

    2006-05-01

    Proteolytic degradation represents a significant barrier to the efficient production of several recombinant proteins in plants, both in vivo during their expression and in vitro during their recovery from source tissues. Here, we describe a strategy to protect recombinant proteins during the recovery process, based on the coexpression of a heterologous proteinase inhibitor acting as a 'mouse trap' against the host proteases during extraction. After confirming the importance of trypsin- and chymotrypsin-like activities in crude protein extracts of potato (Solanum tuberosum L.) leaves, transgenic lines of potato expressing either tomato cathepsin D inhibitor (CDI) or bovine aprotinin, both active against trypsin and chymotrypsin, were generated by Agrobacterium tumefaciens-mediated genetic transformation. Leaf crude protein extracts from CDI-expressing lines, showing decreased levels of cathepsin D-like and ribulose 1,5-bisphosphate carboxylase/oxygenase hydrolysing activities in vitro, conducted decreased turnover rates of the selection marker protein neomycin phosphotransferase II (NPTII) relative to the turnover rates measured for transgenic lines expressing only the marker protein. A similar stabilizing effect on NPTII was observed in leaf protein extracts from plant lines coexpressing bovine aprotinin, confirming the ability of ectopically expressed broad-spectrum serine proteinase inhibitors to reproduce the protein-stabilizing effect of low-molecular-weight proteinase inhibitors generally added to protein extraction media.

  10. A bacterial protease inhibitor protects antigens delivered in oral vaccines from digestion while triggering specific mucosal immune responses.

    PubMed

    Ibañez, Andrés Esteban; Coria, Lorena Mirta; Carabajal, Marianela Verónica; Delpino, María Victoria; Risso, Gabriela Sofía; Cobiello, Paula Gonzalez; Rinaldi, Jimena; Barrionuevo, Paula; Bruno, Laura; Frank, Fernanda; Klinke, Sebastián; Goldbaum, Fernando Alberto; Briones, Gabriel; Giambartolomei, Guillermo Hernán; Pasquevich, Karina Alejandra; Cassataro, Juliana

    2015-12-28

    We report here that a bacterial protease inhibitor from Brucella spp. called U-Omp19 behaves as an ideal constituent for a vaccine formulation against infectious diseases. When co-administered orally with an antigen (Ag), U-Omp19: i) can bypass the harsh environment of the gastrointestinal tract by inhibiting stomach and intestine proteases and consequently increases the half-life of the co-administered Ag at immune inductive sites: Peyer's patches and mesenteric lymph nodes while ii) it induces the recruitment and activation of antigen presenting cells (APCs) and increases the amount of intracellular Ag inside APCs. Therefore, mucosal as well as systemic Ag-specific immune responses, antibodies, Th1, Th17 and CD8(+) T cells are enhanced when U-Omp19 is co-administered with the Ag orally. Finally, this bacterial protease inhibitor in an oral vaccine formulation confers mucosal protection and reduces parasite loads after oral challenge with virulent Toxoplasma gondii.

  11. The PA endonuclease inhibitor RO-7 protects mice from lethal challenge with influenza A or B viruses.

    PubMed

    Jones, Jeremy C; Marathe, Bindumadhav M; Vogel, Peter; Gasser, Rodolfo; Najera, Isabel; Govorkova, Elena A

    2017-02-13

    Current influenza treatment relies on a single class of antiviral drugs, the neuraminidase inhibitors (NAIs), raising concern over the potential emergence of resistant variants and necessitating the development of novel drugs. In recent years, investigational inhibitors targeting the endonuclease activity of the influenza acidic polymerase (PA) protein have yielded encouraging results, although there are only limited data on their in vivo efficacy. Here, we examined the antiviral potential of the PA endonuclease inhibitor RO-7 in prophylactic and therapeutic regimens in BALB/c mice inoculated with influenza A/California/04/2009 (H1N1)pdm09 or B/Brisbane/60/2008 viruses, which represent currently circulating antigenic variants. RO-7 was administered to mice intraperitoneally twice daily at dosages of 6, 15, or 30 mg/kg/day for 5 days, starting 4 h before or 24 or 48 h after virus inoculation, and showed no adverse effects. Prophylactic administration completely protected mice from lethal infection by influenza A or B virus. The level of therapeutic protection conferred depended upon the time of treatment initiation and RO-7 dosage, resulting in 60%-100% and 80%-100% survival with influenza A and B viruses, respectively. RO-7 treatment significantly decreased virus titers in the lung and lessened the extent and severity of lung damage. No PA endonuclease-inhibitor resistance was observed in viruses isolated from lungs of RO-7-treated mice, and the viruses remained susceptible to the drug at nanomolar concentrations in phenotypic assays. These in vivo efficacy results further highlight the potential of RO-7 for development as antiviral therapy for influenza A and B virus infections.

  12. A novel inhibitor of the insulin/IGF signaling pathway protects from age-onset, neurodegeneration-linked proteotoxicity.

    PubMed

    El-Ami, Tayir; Moll, Lorna; Carvalhal Marques, Filipa; Volovik, Yuli; Reuveni, Hadas; Cohen, Ehud

    2014-02-01

    Aging manipulation is an emerging strategy aimed to postpone the manifestation of late-onset neurodegenerative disorders such as Alzheimer's (AD) and Huntington's diseases (HD) and to slow their progression once emerged. Reducing the activity of the insulin/IGF signaling cascade (IIS), a prominent aging-regulating pathway, protects worms from proteotoxicity of various aggregative proteins, including the AD-associated peptide, Aβ- and the HD-linked peptide, polyQ40. Similarly, IGF1 signaling reduction protects mice from AD-like disease. These discoveries suggest that IIS inhibitors can serve as new drugs for the treatment of neurodegenerative maladies including AD and HD. Here, we report that NT219, a novel IIS inhibitor, mediates a long-lasting, highly efficient inhibition of this signaling cascade by a dual mechanism; it reduces the autophosphorylation of the IGF1 receptor and directs the insulin receptor substrates 1 and 2 (IRS 1/2) for degradation. NT219 treatment promotes stress resistance and protects nematodes from AD- and HD-associated proteotoxicity without affecting lifespan. Our discoveries strengthen the theme that IIS inhibition has a therapeutic potential as a cure for neurodegenerative maladies and point at NT219 as a promising compound for the treatment of these disorders through a selective manipulation of aging.

  13. Urethral Reconstruction Using Mesothelial Cell-Seeded Autogenous Granulation Tissue Tube: An Experimental Study in Male Rabbits

    PubMed Central

    Jiang, Shiwei; Xu, Zhonghua; Zhao, Yuanyuan; Yan, Lei; Zhou, Zunlin

    2017-01-01

    Objective. This study was to evaluate the utility of the compound graft for tubularized urethroplasty by seeding mesothelial cells onto autogenous granulation tissue. Methods. Silastic tubes were implanted subcutaneously in 18 male rabbits, of which nine underwent omentum biopsies simultaneously for in vitro expansion of mesothelial cells. The granulation tissue covering the tubes was harvested 2 weeks after operation. Mesothelial cells were seeded onto and cocultured with the tissue for 7 days. A pendulous urethral segment of 1.5 cm was totally excised. Urethroplasty was performed with mesothelial cell-seeded tissue tubes in an end-to-end fashion in nine rabbits and with unseeded grafts in others as controls. Serial urethrograms were performed at 1, 2, and 6 months postoperatively. Meanwhile, the neourethra was harvested and analyzed grossly and histologically. Results. Urethrograms showed cell-seeded grafts maintained wide at each time point, while strictures formation was found in unseeded grafts. Histologically, layers of urothelium surrounded by increasingly organized smooth muscles were observed in seeded grafts. In contrast, myofibroblasts accumulation and extensive scarring occurred in unseeded grafts. Conclusions. Mesothelial cell-seeded granulation tissue tube can be successfully used for tubularized urethroplasty in male rabbits. PMID:28337443

  14. Pest protection conferred by a Beta vulgaris serine proteinase inhibitor gene.

    PubMed

    Smigocki, Ann C; Ivic-Haymes, Snezana; Li, Haiyan; Savić, Jelena

    2013-01-01

    Proteinase inhibitors provide a means of engineering plant resistance to insect pests. A Beta vulgaris serine proteinase inhibitor gene (BvSTI) was fused to the constitutive CaMV35S promoter for over-expression in Nicotiana benthamiana plants to study its effect on lepidopteran insect pests. Independently derived BvSTI transgenic tobacco T2 homozygous progeny were shown to have relatively high BvSTI gene transcript levels. BvSTI-specific polyclonal antibodies cross-reacted with the expected 30 kDA recombinant BvSTI protein on Western blots. In gel trypsin inhibitor activity assays revealed a major clear zone that corresponded to the BvSTI proteinase inhibitor that was not detected in the untransformed control plants. BvSTI-transgenic plants were bioassayed for resistance to five lepidopteran insect pests. Spodoptera frugiperda, S. exigua and Manduca sexta larvae fed BvSTI leaves had significant reductions in larval weights as compared to larvae fed on untransformed leaves. In contrast, larval weights increased relative to the controls when Heliothis virescens and Agrotis ipsilon larvae were fed on BvSTI leaves. As the larvae entered the pupal stage, pupal sizes reflected the overall larval weights. Some developmental abnormalities of the pupae and emerging moths were noted. These findings suggest that the sugar beet BvSTI gene may prove useful for effective control of several different lepidopteran insect pests in genetically modified tobacco and other plants. The sugar beet serine proteinase inhibitor may be more effective for insect control because sugar beet is cropped in restricted geographical areas thus limiting the exposure of the insects to sugar beet proteinase inhibitors and build up of non-sensitive midgut proteases.

  15. Is angiotensin-converting enzyme inhibitors/angiotensin receptor blockers therapy protective against prostate cancer?

    PubMed Central

    Mao, Yeqing; Xu, Xin; Wang, Xiao; Zheng, Xiangyi; Xie, Liping

    2016-01-01

    Emerging evidence suggests that renin-angiotensin system (RAS) may act as a molecular and therapeutic target for treating site-specific cancers, including prostate cancer. However, previous observational studies regarding the association between RAS inhibitors and prostate cancer risk have reported inconsistent results. We examined this association by performing a systematic review and meta-analysis. A total of 20,267 patients from nine cohort studies were enrolled. Compared with non-users of RAS inhibitors, individuals using RAS inhibitors had a reduced risk of prostate cancer (RR 0.92, 95 % CI 0.87-0.98), without statistically significant heterogeneity among studies (P = 0.118 for heterogeneity, I2 = 37.6 %). In addition, when subgroup analyses by study quality and number of cases, more statistically significant associations were observed in studies of high quality (RR 0.93, 95 % CI 0.88-0.97) and large sample size (RR 0.94, 95 % CI 0.91-0.98). There was no evidence of significant publication bias with Begg's test (P = 0.602) or with Egger's test (P = 0.350). Overall, this study indicates that use of RAS inhibitors may be associated with a decreased risk of prostate cancer. Large-scale well designed studies are needed to further explore this association. PMID:26760503

  16. ADAMTS13 Endopeptidase Protects against Vascular Endothelial Growth Factor Inhibitor-Induced Thrombotic Microangiopathy.

    PubMed

    Erpenbeck, Luise; Demers, Melanie; Zsengellér, Zsuzsanna K; Gallant, Maureen; Cifuni, Stephen M; Stillman, Isaac E; Karumanchi, S Ananth; Wagner, Denisa D

    2016-01-01

    Thrombotic microangiopathy (TMA) is a life-threatening condition that affects some, but not all, recipients of vascular endothelial growth factor (VEGF) inhibitors given as part of chemotherapy. TMA is also a complication of preeclampsia, a disease characterized by excess production of the VEGF-scavenging soluble VEGF receptor 1 (soluble fms-like tyrosine kinase 1; sFlt-1). Risk factors for VEGF inhibitor-related TMA remain unknown. We hypothesized that deficiency of the VWF-cleaving ADAMTS13 endopeptidase contributes to the development of VEGF inhibitor-related TMA. ADAMTS13(-/-) mice overexpressing sFlt-1 presented all hallmarks of TMA, including thrombocytopenia, schistocytosis, anemia, and VWF-positive microthrombi in multiple organs. Similar to VEGF inhibitor-related TMA in humans, these mice exhibited severely impaired kidney function and hypertension. In contrast, wild-type mice overexpressing sFlt-1 developed modest hypertension but no other features of TMA. Recombinant ADAMTS13 therapy ameliorated all symptoms of TMA in ADAMTS13(-/-) mice overexpressing sFlt-1 and normalized BP in wild-type mice. ADAMTS13 activity may thus be a critical determinant for the development of TMA secondary to VEGF inhibition. Administration of recombinant ADAMTS13 may serve as a therapeutic approach to treat or prevent thrombotic complications of VEGF inhibition.

  17. Tropism-independent protection of macaques against vaginal transmission of three SHIVs by the HIV-1 fusion inhibitor T-1249.

    PubMed

    Veazey, Ronald S; Ketas, Thomas A; Klasse, Per Johan; Davison, Donna K; Singletary, Morgan; Green, Linda C; Greenberg, Michael L; Moore, John P

    2008-07-29

    We have assessed the potential of the fusion inhibitory peptide T-1249 for development as a vaginal microbicide to prevent HIV-1 sexual transmission. When formulated as a simple gel, T-1249 provided dose-dependent protection to macaques against high-dose challenge with three different SHIVs that used either CCR5 or CXCR4 for infection (the R5 virus SHIV-162P3, the X4 virus SHIV-KU1 and the R5X4 virus SHIV-89.6P), and it also protected against SIVmac251 (R5). Protection of half of the test animals was estimated by interpolation to occur at T-1249 concentrations of approximately 40-130 muM, whereas complete protection was observed at 0.1-2 mM. In vitro, T-1249 had substantial breadth of activity against HIV-1 strains from multiple genetic subtypes and in a coreceptor-independent manner. Thus, at 1 muM in a peripheral blood mononuclear cell-based replication assay, T-1249 inhibited all 29 R5 viruses, all 12 X4 viruses and all 7 R5X4 viruses in the test panel, irrespective of their genetic subtype. Combining lower concentrations of T-1249 with other entry inhibitors (CMPD-167, BMS-C, or AMD3465) increased the proportion of test viruses that could be blocked. In the PhenoSense assay, T-1249 was active against 636 different HIV-1 Env-pseudotyped viruses of varying tropism and derived from clinical samples, with IC(50) values typically clustered in a 10-fold range approximately 10 nM. Overall, these results support the concept of using T-1249 as a component of an entry inhibitor-based combination microbicide to prevent the sexual transmission of diverse HIV-1 variants.

  18. Microfluidic gradient device for studying mesothelial cell migration and the effect of chronic carbon nanotube exposure

    NASA Astrophysics Data System (ADS)

    Zhang, Hanyuan; Lohcharoenkal, Warangkana; Sun, Jianbo; Li, Xiang; Wang, Liying; Wu, Nianqiang; Rojanasakul, Yon; Liu, Yuxin

    2015-07-01

    Cell migration is one of the crucial steps in many physiological and pathological processes, including cancer development. Our recent studies have shown that carbon nanotubes (CNTs), similarly to asbestos, can induce accelerated cell growth and invasiveness that contribute to their mesothelioma pathogenicity. Malignant mesothelioma is a very aggressive tumor that develops from cells of the mesothelium, and is most commonly caused by exposure to asbestos. CNTs have a similar structure and mode of exposure to asbestos. This has raised a concern regarding the potential carcinogenicity of CNTs, especially in the pleural area which is a key target for asbestos-related diseases. In this paper, a static microfluidic gradient device was applied to study the migration of human pleural mesothelial cells which had been through a long-term exposure (4 months) to subcytotoxic concentration (0.02 µg cm-2) of single-walled CNTs (SWCNTs). Multiple migration signatures of these cells were investigated using the microfluidic gradient device for the first time. During the migration study, we observed that cell morphologies changed from flattened shapes to spindle shapes prior to their migration after their sensing of the chemical gradient. The migration of chronically SWCNT-exposed mesothelial cells was evaluated under different fetal bovine serum (FBS) concentration gradients, and the migration speeds and number of migrating cells were extracted and compared. The results showed that chronically SWCNT-exposed mesothelial cells are more sensitive to the gradient compared to non-SWCNT-exposed cells. The method described here allows simultaneous detection of cell morphology and migration under chemical gradient conditions, and also allows for real-time monitoring of cell motility that resembles in vivo cell migration. This platform would be much needed for supporting the development of more physiologically relevant cell models for better assessment and characterization of the

  19. Retinoic acid improves morphology of cultured peritoneal mesothelial cells from patients undergoing dialysis.

    PubMed

    Retana, Carmen; Sanchez, Elsa I; Gonzalez, Sirenia; Perez-Lopez, Alejandro; Cruz, Armando; Lagunas-Munoz, Jesus; Alfaro-Cruz, Carmen; Vital-Flores, Socorro; Reyes, José L

    2013-01-01

    Patients undergoing continuous ambulatory peritoneal dialysis are classified according to their peritoneal permeability as low transporter (low solute permeability) or High transporter (high solute permeability). Factors that determine the differences in permeability between them have not been fully disclosed. We investigated morphological features of cultured human peritoneal mesothelial cells from low or high transporter patients and its response to All trans retinoic Acid (ATRA, vitamin A active metabolite), as compared to non-uremic human peritoneal mesothelial cells. Control cells were isolated from human omentum. High or low transporter cells were obtained from dialysis effluents. Cells were cultured in media containing ATRA (0, 50, 100 or 200 nM). We studied length and distribution of microvilli and cilia (scanning electron microscopy), epithelial (cytokeratin, claudin-1, ZO-1 and occludin) and mesenchymal (vimentin and α-smooth muscle actin) transition markers by immunofluorescence and Western blot, and transforming growth factor β1 expression by Western blot. Low and high transporter exhibited hypertrophic cells, reduction in claudin-1, occludin and ZO-1 expression, cytokeratin and vimentin disorganization and positive α-smooth muscle actin label. Vimentin, α-smooth muscle actin and transforming growth factor-β1 were overexpressed in low transporter. Ciliated cells were diminished in low and high transporters. Microvilli number and length were severely reduced in high transporter. ATRA reduced hypertrophic cells number in low transporter. It also improved cytokeratin and vimentin organization, decreased vimentin and α-smooth muscle actin expression, and increased claudin 1, occludin and ZO-1 expression, in low and high transporter. In low transporter, ATRA reduced transforming growth factor-β1 expression. ATRA augmented percentage of ciliated cells in low and high transporter. It also augmented cilia length in high transporter. Alterations in

  20. The proliferative effects of asbestos-exposed peripheral blood mononuclear cells on mesothelial cells

    PubMed Central

    MAKI, YUHO; NISHIMURA, YASUMITSU; TOYOOKA, SHINICHI; SOH, JUNICHI; TSUKUDA, KAZUNORI; SHIEN, KAZUHIKO; FURUKAWA, MASASHI; MURAOKA, TAKAYUKI; UENO, TSUYOSHI; TANAKA, NORIMITSU; YAMAMOTO, HIROMASA; ASANO, HIROAKI; MAEDA, MEGUMI; KUMAGAI-TAKEI, NAOKO; LEE, SUNI; MATSUZAKI, HIDENORI; OTSUKI, TAKEMI; MIYOSHI, SHINICHIRO

    2016-01-01

    Malignant mesothelioma (MM) is thought to arise from the direct effect of asbestos on mesothelial cells. However, MM takes a long time to develop following exposure to asbestos, which suggests that the effects of asbestos are complex. The present study examined the effects of asbestos exposure on the cell growth of MeT-5A human mesothelial cells via cytokines produced by immune cells. Peripheral blood mononuclear cells (PBMCs) were stimulated with antibodies against cluster of differentiation (CD)3 and CD28 upon exposure to the asbestos chrysotile A (CA) or crocidolite (CR); the growth of MeT-5A cells in media supplemented with PBMC culture supernatants was subsequently examined. MeT-5A cells exhibited an increase in proliferation when grown in supernatant from the 7-day PBMC culture exposed to CA or CR. Analysis of cytokine production demonstrated increased levels of granulocyte colony-stimulating factor (G-CSF), granulocyte-macrophage colony-stimulating factor (GM-CSF), interleukin (IL)-1α, IL-1β, IL-3, IL-5, IL-13 and IL-17A in supernatants. Individual administration of these cytokines, excluding G-CSF and GM-CSF, led to an increase in cell growth of MeT-5A, whereas this effect was not observed following the combined administration of these cytokines. The results indicate that cytokines secreted by immune cells upon exposure to asbestos cause an increase in the growth activity of mesothelial cells, suggesting that alterations in the production of cytokines by immune cells may contribute to tumorigenesis in individuals exposed to asbestos. PMID:27123108

  1. Detection of malignant mesothelioma using nuclear structure of mesothelial cells in effusion cytology specimens.

    PubMed

    Tosun, Akif Burak; Yergiyev, Oleksandr; Kolouri, Soheil; Silverman, Jan F; Rohde, Gustavo K

    2015-04-01

    Mesothelioma is a form of cancer generally caused from previous exposure to asbestos. Although it was considered a rare neoplasm in the past, its incidence is increasing worldwide due to extensive use of asbestos. In the current practice of medicine, the gold standard for diagnosing mesothelioma is through a pleural biopsy with subsequent histologic examination of the tissue. The diagnostic tissue should demonstrate the invasion by the tumor and is obtained through thoracoscopy or open thoracotomy, both being highly invasive surgical operations. On the other hand, thoracocentesis, which is removal of effusion fluid from the pleural space, is a far less invasive procedure that can provide material for cytological examination. In this study, we aim at detecting and classifying malignant mesothelioma based on the nuclear chromatin distribution from digital images of mesothelial cells in effusion cytology specimens. Accordingly, a computerized method is developed to determine whether a set of nuclei belonging to a patient is benign or malignant. The quantification of chromatin distribution is performed by using the optimal transport-based linear embedding for segmented nuclei in combination with the modified Fisher discriminant analysis. Classification is then performed through a k-nearest neighborhood approach and a basic voting strategy. Our experiments on 34 different human cases result in 100% accurate predictions computed with blind cross validation. Experimental comparisons also show that the new method can significantly outperform standard numerical feature-type methods in terms of agreement with the clinical diagnosis gold standard. According to our results, we conclude that nuclear structure of mesothelial cells alone may contain enough information to separate malignant mesothelioma from benign mesothelial proliferations.

  2. Microfluidic gradient device for studying mesothelial cell migration and the effect of chronic carbon nanotube exposure

    PubMed Central

    Zhang, Hanyuan; Lohcharoenkal, Warangkana; Sun, Jianbo; Li, Xiang; Wang, Liying; Wu, Nianqiang; Rojanasakul, Yon; Liu, Yuxin

    2016-01-01

    Cell migration is one of the crucial steps in many physiological and pathological processes, including cancer development. Our recent studies have shown that carbon nanotubes (CNTs), similarly to asbestos, can induce accelerated cell growth and invasiveness that contribute to their mesothelioma pathogenicity. Malignant mesothelioma is a very aggressive tumor that develops from cells of the mesothelium, and is most commonly caused by exposure to asbestos. CNTs have a similar structure and mode of exposure to asbestos. This has raised a concern regarding the potential carcinogenicity of CNTs, especially in the pleural area which is a key target for asbestos-related diseases. In this paper, a static microfluidic gradient device was applied to study the migration of human pleural mesothelial cells which had been through a long-term exposure (4 months) to subcytotoxic concentration (0.02 μg cm−2) of single-walled CNTs (SWCNTs). Multiple migration signatures of these cells were investigated using the microfluidic gradient device for the first time. During the migration study, we observed that cell morphologies changed from flattened shapes to spindle shapes prior to their migration after their sensing of the chemical gradient. The migration of chronically SWCNT-exposed mesothelial cells was evaluated under different fetal bovine serum (FBS) concentration gradients, and the migration speeds and number of migrating cells were extracted and compared. The results showed that chronically SWCNT-exposed mesothelial cells are more sensitive to the gradient compared to non-SWCNT-exposed cells. The method described here allows simultaneous detection of cell morphology and migration under chemical gradient conditions, and also allows for real-time monitoring of cell motility that resembles in vivo cell migration. This platform would be much needed for supporting the development of more physiologically relevant cell models for better assessment and characterization of the

  3. Asbestos fibers and interleukin-1 upregulate the formation of reactive nitrogen species in rat pleural mesothelial cells.

    PubMed

    Choe, N; Tanaka, S; Kagan, E

    1998-08-01

    Nitric oxide radical (.NO) and peroxynitrite anion (ONOO-) have been implicated in lung inflammation and may be important in pleural injury. The present study was undertaken to determine the effects of asbestos exposure and cytokine stimulation on .NO and ONOO- production by rat pleural mesothelial cells. Accordingly, rat parietal pleural mesothelial cells were cultured for 2 to 72 h with or without 50 ng/ml of recombinant interleukin-1beta (IL-1beta) in the presence (1.05 to 8.4 microg/cm2) or absence of crocidolite or chrysotile asbestos fibers. The effects of asbestos were compared with those of carbonyl iron, a nonfibrogenic particulate. Mesothelial cell messenger RNA (mRNA) expression of the inducible form of .NO synthase (iNOS), assessed with the reverse transcription-polymerase chain reaction (RT-PCR), increased progressively from 2 to 12 h in IL-1beta-containing cultures. Nitrite (NO2-), the stable oxidation product of .NO in mesothelial cell conditioned medium, was assayed through the Griess reaction. Both types of asbestos fibers (chrysotile > crocidolite) upregulated the formation of NO2- in mesothelial cells costimulated with IL-1beta in a concentration-dependent and time-dependent fashion. In contrast, carbonyl iron did not upregulate NO2- formation in IL-1beta-stimulated cells. Both types of asbestos fibers also induced iNOS protein expression and the formation of nitrotyrosine in mesothelial cells and greatly induced the formation of nitrate (NO3-), a surrogate marker of ONOO- formation, in IL-1beta-stimulated cells. However, the effects of chrysotile were notably greater than those of crocidolite. These findings may have significance for the induction of pleural injury by asbestos fibers.

  4. DNA damage by smoke: Protection by turmeric and other inhibitors of ROS

    SciTech Connect

    Srinivas, L.; Shalini, V.K. )

    1991-01-01

    Twigs-dry leaves smoke condensate (TDS), as a source of clastogenic ROS and carcinogenic PAH, was investigated for its in vitro DNA-damaging effect in calf thymus DNA and human peripheral lymphocytes. An aqueous turmeric component--Aq.T--with an established antioxidant activity, was tested as a DNA protectant. TDS induced 13-fold damage to calf thymus DNA as judged by the emergence of a DNA damage specific, fluorescent product (em: 405 nm). Aq.T at 800 ng/microL extended 69% protection to calf thymus DNA and was comparable to the other protectants such as curcumin, BHA, vitamin E, SOD, and CAT. In human peripheral lymphocytes, TDS induced extensive DNA damage in comparison with the tumor promoter TPA, as judged by FADU. Aq.T at 300 ng/microL extended 90% protection to human lymphocyte DNA against TDS-induced damage, and was more effective than the other protectants--DABCO, D-mannitol, sodium benzoate, vitamin E (ROS quenchers), SOD, CAT (antioxidant enzymes), tannic acid, flufenamic acid, BHA, BHT, n-PG, curcumin and quercetin (antioxidants). Aq.T offered 65% protection to human lymphocyte DNA against TPA-induced damage and was comparable to SOD. The above results indicate that TDS induces substantial DNA damage in calf thymus DNA and human lymphocytes and Aq.T is an efficient protectant.

  5. In Vivo Islet Protection by a Nuclear Import Inhibitor in a Mouse Model of Type 1 Diabetes

    PubMed Central

    Moore, Daniel J.; Zienkiewicz, Jozef; Kendall, Peggy L.; Liu, Danya; Liu, Xueyan; Veach, Ruth Ann; Collins, Robert D.; Hawiger, Jacek

    2010-01-01

    Background Insulin-dependent Type 1 diabetes (T1D) is a devastating autoimmune disease that destroys beta cells within the pancreatic islets and afflicts over 10 million people worldwide. These patients face life-long risks for blindness, cardiovascular and renal diseases, and complications of insulin treatment. New therapies that protect islets from autoimmune destruction and allow continuing insulin production are needed. Increasing evidence regarding the pathomechanism of T1D indicates that islets are destroyed by the relentless attack by autoreactive immune cells evolving from an aberrant action of the innate, in addition to adaptive, immune system that produces islet-toxic cytokines, chemokines, and other effectors of islet inflammation. We tested the hypothesis that targeting nuclear import of stress-responsive transcription factors evoked by agonist-stimulated innate and adaptive immunity receptors would protect islets from autoimmune destruction. Principal Findings Here we show that a first-in-class inhibitor of nuclear import, cSN50 peptide, affords in vivo islet protection following a 2-day course of intense treatment in NOD mice, which resulted in a diabetes-free state for one year without apparent toxicity. This nuclear import inhibitor precipitously reduces the accumulation of islet-destructive autoreactive lymphocytes while enhancing activation-induced cell death of T and B lymphocytes derived from autoimmune diabetes-prone, non-obese diabetic (NOD) mice that develop T1D. Moreover, in this widely used model of human T1D we noted attenuation of pro-inflammatory cytokine and chemokine production in immune cells. Conclusions These results indicate that a novel form of immunotherapy that targets nuclear import can arrest inflammation-driven destruction of insulin-producing beta cells at the site of autoimmune attack within pancreatic islets during the progression of T1D. PMID:20949090

  6. WRN protects against topo I but not topo II inhibitors by preventing DNA break formation

    PubMed Central

    Christmann, Markus; Tomicic, Maja T.; Gestrich, Christopher; Roos, Wynand P.; Bohr, Vilhelm A.; Kaina, Bernd

    2008-01-01

    The Werner syndrome helicase/3′-exonuclease (WRN) is a major component of the DNA repair and replication machinery. To analyze whether WRN is involved in the repair of topoisomerase-induced DNA damage we utilized U2-OS cells, in which WRN is stably down-regulated (wrn-kd), and the corresponding wild-type cells (wrn-wt). We show that cells not expressing WRN are hypersensitive to the toxic effect of the topoisomerase I inhibitor topotecan, but not to the topoisomerase II inhibitor etoposide. This was shown by mass survival assays, colony formation and induction of apoptosis. Upon topotecan treatment WRN deficient cells showed enhanced DNA replication inhibition and S-phase arrest, whereas after treatment with etoposide they showed the same cell cycle response as the wild-type. A considerable difference between WRN and wild-type cells was also observed for DNA single-and double-strand break formation in response to topotecan. Topotecan induced most DNA single-strand breaks 6 h after treatment. In both wrn-wt and wrn-kd cells these breaks were repaired at similar kinetics. However, in wrn-kd but not wrn-wt cells they were converted into DNA double-strand breaks (DSBs) at high frequency, as shown by neutral comet assay and phosphorylation of H2AX. Our data provide evidence that WRN is involved in the repair of topoisomerase I, but not topoisomerase II-induced DNA damage, most likely via preventing the conversion of DNA single-strand breaks into DSBs during the resolution of stalled replication forks at topo I–DNA complexes. We suggest that the WRN status of tumor cells impacts anticancer therapy with topoisomerase I, but not topoisomerase II inhibitors. PMID:18805512

  7. Bradykinin-mediated cardiovascular protective actions of ACE inhibitors. A new dimension in anti-ischaemic therapy?

    PubMed

    Remme, W J

    1997-01-01

    become operative and clinically important during long term oral ACE inhibitor therapy when endothelial function improves, and may subsequently protect against the vasoconstrictor effect of neurohormonal activation. As it is unlikely that the mechanisms mentioned above are only relevant in patients with ventricular dysfunction or heart failure, several large controlled trials are currently examining the long term anti-ischaemic and cardiovascular protective effects of ACE inhibition in patients at risk of a cardiovascular event [Heart Outcomes Prevention Evaluation study (HOPE)], with a normal cardiac function [Prevention of Events with ACE inhibition study (PEACE)] or in all patients with coronary artery disease irrespective of cardiac function [EUropean trial of Reduction Of cardiac events with Perindopril in stable coronary Artery disease (EUROPA)].

  8. Interleukin-6 production by peritoneal mesothelial cells and its regulation by inflammatory factors in rats administered carbon tetrachloride intraperitoneally

    SciTech Connect

    Yamaji, Kenzaburo; Ohnishi, Ken-ichi; Zuinen, Ryoji; Ochiai, Yosuke; Chikuma, Toshiyuki; Hojo, Hiroshi

    2008-01-01

    We previously reported that a high level of interleukin-6 (IL-6), which is protective against CCl{sub 4}-induced hepatotoxicity, is produced in the peritoneal cavity in the early period after ip carbon tetrachloride (CCl{sub 4}) administration. The objective of this study was to identify the tissues and cells involved in IL-6 production and clarify the mechanisms underlying its regulation. IL-6 mRNA levels increased significantly in the serous membranes of the mesentery and peritoneum, but not in the parenchymal organs including liver, kidney and spleen, 3 h after ip CCl{sub 4} administration. Peritoneal mesothelial cells (PMCs), a major cell population in serous membranes, were isolated from rat peritoneal walls by trypsin digestion and cultured with peritoneal exudate fluid (PEF) from CCl{sub 4}-administered rats. PMCs produced a high level of IL-6 in the presence of PEF recovered 0.5 h after ip CCl{sub 4} administration. Analyses of PEF revealed that the levels of prostaglandin E{sub 2} (PGE{sub 2}), histamine, IL-1{alpha}, IL-1{beta} and tumor necrosis factor-{alpha} (TNF-{alpha}) increased immediately after ip CCl{sub 4} administration. These inflammatory factors, except for histamine, stimulated IL-6 production to varying degrees, in the following order: IL-1{alpha} > IL-1{beta} > TNF-{alpha} >> PGE{sub 2}. In summary, the present study indicates that the high level of IL-6 observed in the rat peritoneal cavity after ip CCl{sub 4} administration is at least partially produced by PMCs stimulated cooperatively with IL-1{alpha}, IL-1{beta}, TNF-{alpha} and PGE{sub 2}. These inflammatory factors may be released from tissues or cells either stimulated or injured directly by CCl{sub 4}.

  9. The protein kinase 2 inhibitor tetrabromobenzotriazole protects against renal ischemia reperfusion injury

    PubMed Central

    Ka, Sun-O; Hwang, Hong Pil; Jang, Jong-Hwa; Hyuk Bang, In; Bae, Ui-Jin; Yu, Hee Chul; Cho, Baik Hwan; Park, Byung-Hyun

    2015-01-01

    Protein kinase 2 (CK2) activation was reported to enhance reactive oxygen species production and activate the nuclear factor κB (NF-κB) pathway. Because oxidative stress and inflammation are critical events for tissue destruction during ischemia reperfusion (I/R), we sought to determine whether CK2 was important in the renal response to I/R. Mice underwent 25 min of renal ischemia and were then reperfused. We confirmed an increased expression of CK2α during the reperfusion period, while expression of CK2β remained consistent. We administered tetrabromobenzotriazole (TBBt), a selective CK2α inhibitor before inducing I/R injury. Mice subjected to I/R injury showed typical patterns of acute kidney injury; blood urea nitrogen and serum creatinine levels, tubular necrosis and apoptosis, inflammatory cell infiltration and proinflammatory cytokine production, and oxidative stress were markedly increased when compared to sham mice. However, pretreatment with TBBt abolished these changes and improved renal function and architecture. Similar renoprotective effects of CK2α inhibition were observed for emodin. Renoprotective effects of CK2α inhibition were associated with suppression of NF-κB and mitogen activated protein kinase (MAPK) pathways. Taken together, these results suggest that CK2α mediates proapoptotic and proinflammatory signaling, thus the CK2α inhibitor may be used to prevent renal I/R injuries observed in clinical settings. PMID:26423352

  10. Genomic reprograming analysis of the Mesothelial to Mesenchymal Transition identifies biomarkers in peritoneal dialysis patients

    PubMed Central

    Ruiz-Carpio, Vicente; Sandoval, Pilar; Aguilera, Abelardo; Albar-Vizcaíno, Patricia; Perez-Lozano, María Luisa; González-Mateo, Guadalupe T.; Acuña-Ruiz, Adrián; García-Cantalejo, Jesús; Botías, Pedro; Bajo, María Auxiliadora; Selgas, Rafael; Sánchez-Tomero, José Antonio; Passlick-Deetjen, Jutta; Piecha, Dorothea; Büchel, Janine; Steppan, Sonja; López-Cabrera, Manuel

    2017-01-01

    Peritoneal dialysis (PD) is an effective renal replacement therapy, but a significant proportion of patients suffer PD-related complications, which limit the treatment duration. Mesothelial-to-mesenchymal transition (MMT) contributes to the PD-related peritoneal dysfunction. We analyzed the genetic reprograming of MMT to identify new biomarkers that may be tested in PD-patients. Microarray analysis revealed a partial overlapping between MMT induced in vitro and ex vivo in effluent-derived mesothelial cells, and that MMT is mainly a repression process being higher the number of genes that are down-regulated than those that are induced. Cellular morphology and number of altered genes showed that MMT ex vivo could be subdivided into two stages: early/epithelioid and advanced/non-epithelioid. RT-PCR array analysis demonstrated that a number of genes differentially expressed in effluent-derived non-epithelioid cells also showed significant differential expression when comparing standard versus low-GDP PD fluids. Thrombospondin-1 (TSP1), collagen-13 (COL13), vascular endothelial growth factor A (VEGFA), and gremlin-1 (GREM1) were measured in PD effluents, and except GREM1, showed significant differences between early and advanced stages of MMT, and their expression was associated with a high peritoneal transport status. The results establish a proof of concept about the feasibility of measuring MMT-associated secreted protein levels as potential biomarkers in PD. PMID:28327551

  11. The Mesothelial Origin of Carcinoma Associated-Fibroblasts in Peritoneal Metastasis

    PubMed Central

    Rynne-Vidal, Angela; Jiménez-Heffernan, José Antonio; Fernández-Chacón, Concepción; López-Cabrera, Manuel; Sandoval, Pilar

    2015-01-01

    Solid tumors are complex and unstructured organs that, in addition to cancer cells, also contain other cell types. Carcinoma-associated fibroblasts (CAFs) represent an important population in the tumor microenviroment and participate in several stages of tumor progression, including cancer cell migration/invasion and metastasis. During peritoneal metastasis, cancer cells detach from the primary tumor, such as ovarian or gastrointestinal, disseminate through the peritoneal fluid and colonize the peritoneum. Tumor cells metastasize by attaching to and invading through the mesothelial cell (MC) monolayer that lines the peritoneal cavity, then colonizing the submesothelial compact zone where CAFs accumulate. CAFs may derive from different sources depending on the surrounding metastatic niche. In peritoneal metastasis, a sizeable subpopulation of CAFs originates from MCs through a mesothelial-to-mesenchymal transition (MMT), which promotes adhesion, invasion, vascularization and subsequent tumor growth. The bidirectional communication between cancer cells and MC-derived CAFs via secretion of a wide range of cytokines, growth factors and extracellular matrix components seems to be crucial for the establishment and progression of the metastasis in the peritoneum. This manuscript provides a comprehensive review of novel advances in understanding how peritoneal CAFs provide cancer cells with a supportive microenvironment, as well as the development of future therapeutic approaches by interfering with the MMT in the peritoneum. PMID:26426054

  12. Diffuse hyperplastic mesothelial cells in multiple lymph nodes: case report with review of the literature

    PubMed Central

    Peng, Libo; Shen, Qin; Liu, Xia; Wang, Jiandong; Shi, Shanshan; Yu, Bo; Zhou, Xiaojun

    2013-01-01

    We report a case of diffuse hyperplastic mesothelial cells in multiple lymph nodes. Microscopically, the lymph nodes had a normal follicular pattern. The lymphatic sinus was extremely expanded, within the sinuses the epithelial-like cells proliferated actively in the form of sheets and clusters. Epithelioid-like cells had eosinophilic cytoplasm, prominent nucleoli and vesicular nuclei. Mitotic figures were rarely observed. These cells were immunopositive for Calretinin, CK5/6, D2-40, MC and Ckpan and immunonegative for S-100, HMB45, MelanA, TTF-1, CDX-2, Villin, ALK, CD30, CD20, CD3, CD1a and CD68. In addition, during a 22 months follow-up period failed to identify any malignant neoplasms, thus confirming the benign nature of these cells. It is the first reported case of diffuse hyperplastic of mesothelial cells mainly in the cervical lymph nodes associated with systemic multiple lymph node involvement. Awareness of this event is important for the pathologist in preventing the misdiagnosis of malignancy. PMID:23638225

  13. Source of peritoneal proteoglycans. Human peritoneal mesothelial cells synthesize and secrete mainly small dermatan sulfate proteoglycans.

    PubMed Central

    Yung, S.; Thomas, G. J.; Stylianou, E.; Williams, J. D.; Coles, G. A.; Davies, M.

    1995-01-01

    This study describes experiments that compare the proteoglycans (PGs) extracted from the dialysate from patients receiving continuous peritoneal ambulatory dialysis (CAPD) with those secreted by metabolically labeled human peritoneal mesothelial cells in vitro. The PGs isolated from both sources were predominantly small chondroitin sulfate/dermatan sulfate PGs. Western blot of the core proteins obtained after chondroitin ABC lyase treatment with specific antibodies identified decorin and biglycan. With [35S]sulfate and [35S]methionine as labeling precursors it was shown that dermatan sulfate rather than chondroitin sulfate were the major glycosaminoglycan chains and that decorin was the predominant species. These data provide the first evidence that human peritoneal mesothelial cells may be the principal source of PGs in the peritoneum. Given the proposed functions of decorin and biglycan, the results suggest that these PGs may be involved in the control of transforming growth factor-beta activity and collagen fibril formation in the peritoneum. Images Figure 2 Figure 7 Figure 8 PMID:7856761

  14. Genomic reprograming analysis of the Mesothelial to Mesenchymal Transition identifies biomarkers in peritoneal dialysis patients.

    PubMed

    Ruiz-Carpio, Vicente; Sandoval, Pilar; Aguilera, Abelardo; Albar-Vizcaíno, Patricia; Perez-Lozano, María Luisa; González-Mateo, Guadalupe T; Acuña-Ruiz, Adrián; García-Cantalejo, Jesús; Botías, Pedro; Bajo, María Auxiliadora; Selgas, Rafael; Sánchez-Tomero, José Antonio; Passlick-Deetjen, Jutta; Piecha, Dorothea; Büchel, Janine; Steppan, Sonja; López-Cabrera, Manuel

    2017-03-22

    Peritoneal dialysis (PD) is an effective renal replacement therapy, but a significant proportion of patients suffer PD-related complications, which limit the treatment duration. Mesothelial-to-mesenchymal transition (MMT) contributes to the PD-related peritoneal dysfunction. We analyzed the genetic reprograming of MMT to identify new biomarkers that may be tested in PD-patients. Microarray analysis revealed a partial overlapping between MMT induced in vitro and ex vivo in effluent-derived mesothelial cells, and that MMT is mainly a repression process being higher the number of genes that are down-regulated than those that are induced. Cellular morphology and number of altered genes showed that MMT ex vivo could be subdivided into two stages: early/epithelioid and advanced/non-epithelioid. RT-PCR array analysis demonstrated that a number of genes differentially expressed in effluent-derived non-epithelioid cells also showed significant differential expression when comparing standard versus low-GDP PD fluids. Thrombospondin-1 (TSP1), collagen-13 (COL13), vascular endothelial growth factor A (VEGFA), and gremlin-1 (GREM1) were measured in PD effluents, and except GREM1, showed significant differences between early and advanced stages of MMT, and their expression was associated with a high peritoneal transport status. The results establish a proof of concept about the feasibility of measuring MMT-associated secreted protein levels as potential biomarkers in PD.

  15. Mesothelial-to-mesenchymal transition in the pathogenesis of post-surgical peritoneal adhesions.

    PubMed

    Sandoval, Pilar; Jiménez-Heffernan, José A; Guerra-Azcona, Gonzalo; Pérez-Lozano, María L; Rynne-Vidal, Ángela; Albar-Vizcaíno, Patricia; Gil-Vera, Fernando; Martín, Paloma; Coronado, María José; Barcena, Carmen; Dotor, Javier; Majano, Pedro Lorenzo; Peralta, Abelardo Aguilera; López-Cabrera, Manuel

    2016-05-01

    Peritoneal adhesions (PAs) are fibrotic bands formed between bowel loops, solid organs, and the parietal peritoneum, which may appear following surgery, infection or endometriosis. They represent an important health problem with no effective treatment. Mesothelial cells (MCs) line the peritoneal cavity and undergo a mesothelial-to-mesenchymal transition (MMT) under pathological conditions, transforming into myofibroblasts, which are abundant in peritoneal fibrotic tissue. The aim of this study was to investigate if peritoneal MCs undergo a MMT contributing to the formation of post-surgical adhesions. Biopsies from patients with PAs were analysed by immunohistochemistry, immunofluorescence, and quantitative RT-PCR. A mouse model of PAs based on ischaemic buttons was used to modulate MMT by blocking the transforming growth factor-beta (TGF-β) pathway. The severity of adhesions and MMT-related marker expression were studied. We observed myofibroblasts derived from the conversion of MCs in submesothelial areas of patients with PAs. In addition, MMT-related markers were dysregulated in adhesion zones when compared to distant normal peritoneal tissue of the same patient. In animal experiments, blockage of TGF-β resulted in molecular reprogramming of markers related to the mesenchymal conversion of MCs and in a significant decrease in the severity of the adhesions. These data indicate for the first time that MMT is involved in PA pathogenesis. This finding opens new therapeutic strategies to interfere with adhesion formation by modulating MMT with a wide range of pharmacological agents.

  16. Phagocytosis of crocidolite asbestos induces oxidative stress, DNA damage, and apoptosis in mesothelial cells.

    PubMed

    Liu, W; Ernst, J D; Broaddus, V C

    2000-09-01

    Phagocytosis of asbestos fibers may be a necessary step for asbestos-induced injury to mesothelial cells, but this has not been established because quantification of fiber uptake is difficult and ways to increase fiber phagocytosis without also increasing total dose were not available. We quantified phagocytosis by counting intracellular fibers after removing adherent fibers with trypsin; we selectively increased fiber phagocytosis by coating crocidolite asbestos fibers with the adhesive serum protein vitronectin (VN), which we have shown increases fiber uptake via integrins. We measured various aspects of asbestos-induced cytotoxicity: intracellular oxidation by the shift of fluorescence of cells loaded with an oxidative probe, DNA strand breakage by the alkaline unwinding ethidium bromide fluorometric assay, apoptosis by annexin V binding and by nuclear morphology, and cell-cycle progression. We found that, compared with control fibers or particles, asbestos increased intracellular oxidation, DNA strand breakage, and apoptosis. Selective increases in fiber uptake by VN-coating of the fibers further increased the oxidation, DNA strand breakage, and apoptosis, and induced a cell-cycle arrest in G2/M. Selective decreases in fiber uptake by cytochalasin or by integrin blockade with RGD peptides inhibited several of these measures of injury. We conclude that phagocytosis is important and perhaps necessary for asbestos-induced injury to mesothelial cells.

  17. Iron overload as a major targetable pathogenesis of asbestos-induced mesothelial carcinogenesis.

    PubMed

    Toyokuni, Shinya

    2014-01-01

    Few people expected that asbestos, a fibrous mineral, would be carcinogenic to humans. In fact, asbestos is a definite carcinogen in humans, causing a rare but aggressive cancer called malignant mesothelioma (MM). Mesothelial cells line the three somatic cavities and thus do not face the outer surface, but reduce the friction among numerous moving organs. MM has several characteristics: extremely long incubation period of 30-40 years after asbestos exposure, difficulty in clinical diagnosis at an early stage, and poor prognosis even under the current multimodal therapies. In Japan, 'Kubota shock' attracted considerable social attention in 2005 for asbestos-induced mesothelioma and, thereafter, the government enacted a law to provide the people suffering from MM a financial allowance. Several lines of recent evidence suggest that the major pathology associated with asbestos-induced MM is local iron overload, associated with asbestos exposure. Preclinical studies to prevent MM after asbestos exposure with iron reduction are in progress. In addition, novel target genes in mesothelial carcinogenesis have been discovered with recently recognized mesothelioma-prone families. Development of an effective preventive strategy is eagerly anticipated because of the long incubation period for MM.

  18. A novel complex I inhibitor protects against hypertension-induced left ventricular hypertrophy.

    PubMed

    Matsumura, Nobutoshi; Robertson, Ian M; Hamza, Shereen M; Soltys, Carrie-Lynn M; Sung, Miranda M; Masson, Grant; Beker, Donna L; Dyck, Jason R B

    2017-03-01

    Since left ventricular hypertrophy (LVH) increases the susceptibility for the development of other cardiac conditions, pharmacotherapy that mitigates pathological cardiac remodeling may prove to be beneficial in patients with LVH. Previous work has shown that the activation of the energy-sensing kinase AMP-activated protein kinase (AMPK) can inhibit some of the molecular mechanisms that are involved in LVH. Of interest, metformin activates AMPK through its inhibition of mitochondrial complex I in the electron transport chain and can prevent LVH induced by pressure overload. However, metformin has additional cellular effects unrelated to AMPK activation, raising questions about whether mitochondrial complex I inhibition is sufficient to reduce LVH. Herein, we characterize the cardiac effects of a novel compound (R118), which is a more potent complex I inhibitor than metformin and is thus used at a much lower concentration. We show that R118 activates AMPK in the cardiomyocyte, inhibits multiple signaling pathways involved in LVH, and prevents Gq protein-coupled receptor agonist-induced prohypertrophic signaling. We also show that in vivo administration of R118 prevents LVH in a mouse model of hypertension, suggesting that R118 can directly modulate the response of the cardiomyocyte to stress. Of importance, we also show that while R118 treatment prevents adaptive remodelling in response to elevated afterload, it does so without compromising systolic function, improves myocardial energetics, and prevents a decline in diastolic function in hypertensive mice. Taken together, our data suggest that inhibition of mitochondrial complex I may be worthy of future investigation for the treatment of LVH.NEW & NOTEWORTHY Inhibition of mitochondrial complex I by R118 reduces left ventricular hypertrophy (LVH) and improves myocardial energetics as well as diastolic function without compromising systolic function. Together, these effects demonstrate the therapeutic potential of

  19. Reduced estradiol synthesis by letrozole, an aromatase inhibitor, is protective against development of pentylenetetrazole-induced kindling in mice.

    PubMed

    Rashid, Davood; Panda, B P; Vohora, Divya

    2015-11-01

    Neurosteroids, such as testosterone and their metabolites, are known to modulate neuronal excitability. The enzymes regulating the metabolism of these neurosteroids, thus, may be targeted as a noval strategy for the development of new antiepileptic drugs. The present work targeted two such enzymes i,e aromatase and 5α-reductase in order to explore the potential of letrozole (an aromatase inhibitor) on pentylenetetrazole (PTZ)-induced kindling in mice and the ability of finasteride (a 5α-reductase inhibitor) to modulate any such effects. PTZ (30 mg/kg, i.p.), when administered once every two days (for a total of 24 doses) induced kindling in Swiss albino mice. Letrozole (1 mg/kg, p.o.), administered prior to PTZ, significantly reduced the % incidence of kindling, delayed mean onset time of seizures and reduced seizure severity score. Letrozole reduced the levels of plasma 17β-estradiol after induction of kindling. The concurrent administration of finasteride and letrozole produced effects similar to letrozole on PTZ-kindling and on estradiol levels. This implies that the ability of letrozole to redirect the synthesis of dihydrotestosterone (DHT) and 5α-androstanediol from testosterone doesn't appear to play a significant role in the protective effects of letrozole against PTZ kindling. Letrozole, however, increased the levels of 5α-DHT in mice plasma. The aromatase inhibitors, thus, may be exploited for inhibiting the synthesis of proconvulsant (17β-estradiol) and/or redirecting the synthesis of anticonvulsant (DHT and 5α-androstanediol) neurosteroids.

  20. Vitronectin enhances internalization of crocidolite asbestos by rabbit pleural mesothelial cells via the integrin alpha v beta 5.

    PubMed Central

    Boylan, A M; Sanan, D A; Sheppard, D; Broaddus, V C

    1995-01-01

    The mechanism by which pleural mesothelial cells, the likely progenitor cells of asbestos-induced mesothelioma, recognize and internalize crocidolite asbestos is unknown. Because incubation of asbestos fibers with serum increases their association with cells, we asked whether a protein coat on asbestos increased internalization of fibers via specific cellular receptors. Coating crocidolite with citronectin, but not with fibronectin or other proteins, increased fiber internalization by rabbit pleural mesothelial cells, as measured by a new technique using fluorescence confocal microscopy. Receptors for vitronectin, alpha v beta 3 and alpha v beta 5, were identified on mesothelial cells. Inhibiting vitronectin receptors by plating cells on a vitronectin substrate or incubating cells with excess soluble vitronectin reduced internalization of vitronectin-coated crocidolite. Inhibition of alpha v beta 5, but not alpha v beta 3, with blocking antibodies similarly reduced internalization. In addition, alpha v beta 5, but not alpha v beta 3, showed immunocytochemical colocalization with fibers. Of biologic relevance, coating crocidolite with serum also increased internalization via alpha v beta 5, an effect dependent on the vitronectin in serum. We conclude that pleural mesothelial cells recognize and internalize vitronectin- and serum-coated asbestos via the integrin alpha v beta 5. Since integrins initiate some of the same signaling pathways as does asbestos, our findings may provide insights into the mechanisms of asbestos-induced biologic effects. Images PMID:7560092

  1. Differences and similarities between carbon nanotubes and asbestos fibers during mesothelial carcinogenesis: shedding light on fiber entry mechanism.

    PubMed

    Nagai, Hirotaka; Toyokuni, Shinya

    2012-08-01

    The emergence of nanotechnology represents an important milestone, as it opens the way to a broad spectrum of applications for nanomaterials in the fields of engineering, industry and medicine. One example of nanomaterials that have the potential for widespread use is carbon nanotubes, which have a tubular structure made of graphene sheets. However, there have been concerns that they may pose a potential health risk due to their similarities to asbestos, namely their high biopersistence and needle-like structure. We recently found that despite these similarities, carbon nanotubes and asbestos differ in certain aspects, such as their mechanism of entry into mesothelial cells. In the study, we showed that non-functionalized, multi-walled carbon nanotubes enter mesothelial cells by directly piercing through the cell membrane in a diameter- and rigidity-dependent manner, whereas asbestos mainly enters these cells through the process of endocytosis, which is independent of fiber diameter. In this review, we discuss the key differences, as well as similarities, between asbestos fibers and carbon nanotubes. We also summarize previous reports regarding the mechanism of carbon nanotube entry into non-phagocytic cells. As the entry of fibers into mesothelial cells is a crucial step in mesothelial carcinogenesis, we believe that a comprehensive study on the differences by which carbon nanotubes and asbestos fibers enter into non-phagocytic cells will provide important clues for the safer manufacture of carbon nanotubes through strict regulation on fiber characteristics, such as diameter, surface properties, length and rigidity.

  2. Mesothelial papillary proliferation of the pleura associated with radiation therapy: Does it have a role in the pathogenesis of mesothelioma

    SciTech Connect

    Jagirdar, J.; Frydman, C.; Sakurai, H.; Dumitrescu, O.

    1989-03-01

    Diffuse papillary proliferation of mesothelial cells in the pleura mimicking metastatic carcinoma was seen four weeks following radiation therapy for a Pancoast tumor. Such papillary proliferations are not observed incidentally and are envisioned to occur during asbestos-induced carcinogenesis. We postulate that similar papillary lesions may serve as a link in the pathogenesis of radiation-induced mesotheliomas.

  3. The c-Abl inhibitor, nilotinib, protects dopaminergic neurons in a preclinical animal model of Parkinson's disease.

    PubMed

    Karuppagounder, Senthilkumar S; Brahmachari, Saurav; Lee, Yunjong; Dawson, Valina L; Dawson, Ted M; Ko, Han Seok

    2014-05-02

    c-Abl is activated in the brain of Parkinson's disease (PD) patients and in 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-intoxicated mice where it inhibits parkin through tyrosine phosphorylation leading to the accumulation of parkin substrates, and neuronal cell death. In the present study, we evaluated the in vivo efficacy of nilotinib, a brain penetrant c-Abl inhibitor, in the acute MPTP-induced model of PD. Our results show that administration of nilotinib reduces c-Abl activation and the levels of the parkin substrate, PARIS, resulting in prevention of dopamine (DA) neuron loss and behavioral deficits following MPTP intoxication. On the other hand, we observe no reduction in the tyrosine phosphorylation of parkin and the parkin substrate, AIMP2 suggesting that the protective effect of nilotinib may, in part, be parkin-independent or to the pharmacodynamics properties of nilotinib. This study provides a strong rationale for testing other brain permeable c-Abl inhibitors as potential therapeutic agents for the treatment of PD.

  4. The c-Abl inhibitor, Nilotinib, protects dopaminergic neurons in a preclinical animal model of Parkinson's disease

    PubMed Central

    Karuppagounder, Senthilkumar S.; Brahmachari, Saurav; Lee, Yunjong; Dawson, Valina L.; Dawson, Ted M.; Ko, Han Seok

    2014-01-01

    c-Abl is activated in the brain of Parkinson's disease (PD) patients and in 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-intoxicated mice where it inhibits parkin through tyrosine phosphorylation leading to the accumulation of parkin substrates, and neuronal cell death. In the present study, we evaluated the in vivo efficacy of nilotinib, a brain penetrant c-Abl inhibitor, in the acute MPTP-induced model of PD. Our results show that administration of nilotinib reduces c-Abl activation and the levels of the parkin substrate, PARIS, resulting in prevention of dopamine (DA) neuron loss and behavioral deficits following MPTP intoxication. On the other hand, we observe no reduction in the tyrosine phosphorylation of parkin and the parkin substrate, AIMP2 suggesting that the protective effect of nilotinib may, in part, be parkin-independent or to the pharmacodynamics properties of nilotinib. This study provides a strong rationale for testing other brain permeable c-Abl inhibitors as potential therapeutic agents for the treatment of PD. PMID:24786396

  5. Protection of macaques from vaginal SHIV challenge by an orally delivered CCR5 inhibitor.

    PubMed

    Veazey, Ronald S; Springer, Martin S; Marx, Preston A; Dufour, Jason; Klasse, Per Johan; Moore, John P

    2005-12-01

    Pre-exposure oral prophylaxis with antiviral drugs is a potential method for preventing transmission of human immunodeficiency virus type 1 (HIV-1). We show that oral delivery of CMPD167, a small molecule that binds to the CCR5 coreceptor, for 10-14 d can protect a substantial proportion of macaques from vaginal infection with a CCR5-using virus (SHIV-162P3). The macaques that became infected despite receiving CMPD167 had reduced plasma viremia levels during the earliest stages of infection.

  6. Renal Protective Effect of DPP-4 Inhibitors in Type 2 Diabetes Mellitus Patients: A Cohort Study

    PubMed Central

    Byun, JungHyun; Yoon, Dukyong; Jeon, Ja Young; Han, Seung Jin; Kim, Dae Jung; Lee, Kwan-Woo

    2016-01-01

    Aims. Dipeptidyl-peptidase IV inhibitors (DPP-4i) are among the most popular oral antidiabetic agents. However, the effects of DPP-4i on diabetic nephropathy are not well-established. The aim of this study was to determine the renoprotective effects of DPP-4i, using albuminuria and glomerular filtration rate (GFR) as indicators, in type 2 diabetes mellitus (T2DM) patients. Methods. This retrospective observational cohort study used the clinical database of a tertiary hospital. The changes of urine albumin/creatinine ratio (UACR), estimated GFR (eGFR), and metabolic parameters after treatment were compared with the changes of those parameters before treatment using paired Student's t-test. Results. The mean UACR in the entire study population decreased to approximately 45 mg/g 1 year after DPP-4i treatment, while it was increased approximately 39 mg/g 1 year before DPP-4i treatment (p < 0.05). Patients with macroalbuminuria showed a significant reduction in albumin levels after DPP-4i treatment (p < 0.05); however, patients with microalbuminuria and normoalbuminuria did not show improvements in albuminuria levels after treatment. Although eGFR was not changed 1 year after DPP-4i treatment, reductions in eGFR were slowed in patients with microalbuminuria and reversed in the macroalbuminuria or normoalbuminuria groups, 4 years after treatment. Conclusions. Administration of DPP-4i reduces urine albumin excretion and mitigates reduction of eGFR in T2DM patients. PMID:28119930

  7. Leishmania donovani P23 protects parasites against HSP90 inhibitor-mediated growth arrest.

    PubMed

    Hombach, Antje; Ommen, Gabi; Sattler, Victoria; Clos, Joachim

    2015-07-01

    In Leishmania donovani, the HSP90 chaperone complex plays an essential role in the control of the parasite's life cycle, general viability and infectivity. Several of the associated co-chaperones were also shown to be essential for viability and/or infectivity to mammalian cells. Here, we identify and describe the co-chaperone P23 and distinguish its function from that of the structurally related small heat shock protein HSP23. P23 is expressed constitutively and associates itself with members of the HSP90 complex, i.e. HSP90 and Sti1. Viable P23 gene replacement mutants could be raised and confirmed as null mutants without deleterious effects on viability under a variety of physiological growth conditions. The null mutant also displays near-wild-type infectivity, arguing against a decisive role played by P23 in laboratory settings. However, the P23 null mutant displays a marked hypersensitivity against HSP90 inhibitors geldanamycin and radicicol. P23 also appears to affect the radicicol resistance of a HSP90 Leu33-Ile mutant described previously. Therefore, the annotation of L. donovani P23 as HSP90-interacting co-chaperone is confirmed.

  8. Combination of ACE inhibitor with nicorandil provides further protection in chronic kidney disease.

    PubMed

    Shiraishi, Takeshi; Tamura, Yoshifuru; Taniguchi, Kei; Higaki, Masato; Ueda, Shuko; Shima, Tomoko; Nagura, Michito; Nakagawa, Takahiko; Johnson, Richard J; Uchida, Shunya

    2014-12-15

    An inhibition in the renin-angiotensin system (RAS) is one of the most widely used therapies to treat chronic kidney disease. However, its effect is occasionally not sufficient and additional treatments may be required. Recently, we reported that nicorandil exhibited renoprotective effects in a mouse model of diabetic nephropathy. Here we examined if nicorandil can provide an additive protection on enalapril in chronic kidney disease. Single treatment with either enalapril or nicorandil significantly ameliorated glomerular and tubulointerstitial injury in the rat remnant kidney while the combination of these two compounds provided additive effects. In addition, an increase in oxidative stress in remnant kidney was also blocked by either enalapril or nicorandil while the combination of the drugs was more potent. A mechanism was likely due for nicorandil to preventing manganase superoxide dismutase (MnSOD) and sirtuin (Sirt)3 from being reduced in injured kidneys. A study with cultured podocytes indicated that the antioxidative effect could be mediated through sulfonylurea receptor (SUR) in the mitochondrial KATP channel since blocking SUR with glibenclamide reduced MnSOD and Sirt3 expression in podocytes. In conclusion, nicorandil may synergize with enalapril to provide superior protection in chronic kidney disease.

  9. Renin–angiotensin system inhibitors protect against age-related changes in rat liver mitochondrial DNA content and gene expression

    PubMed Central

    de Cavanagh, Elena M.V.; Flores, Idhaliz; Ferder, Marcelo; Inserra, Felipe; Ferder, León

    2016-01-01

    Chronic renin–angiotensin system inhibition protects against liver fibrosis, ameliorates age-associated mitochondrial dysfunction and increases rodent lifespan. We hypothesized that life-long angiotensin-II-mediated stimulation of oxidant generation might participate in mitochondrial DNA “common deletion” formation, and the resulting impairment of bioenergetic capacity. Enalapril (10 mg/kg/d) or losartan (30 mg/kg/d) administered during 16.5 months were unable to prevent the age-dependent accumulation of rat liver mitochondrial DNA “common deletion”, but attenuated the decrease of mitochondrial DNA content. This evidence – together with the enhancement of NRF-1 and PGC-1 mRNA contents – seems to explain why enalapril and losartan improved mitochondrial functioning and lowered oxidant production, since both the absolute number of mtDNA molecules and increased NRF-1 and PGC-1 transcription are positively related to mitochondrial respiratory capacity, and PGC-1 protects against increases in ROS production and damage. Oxidative stress evoked by abnormal respiratory function contributes to the pathophysiology of mitochondrial disease and human aging. If the present mitochondrial actions of renin–angiotensin system inhibitors are confirmed in humans they may modify the therapeutic significance of that strategy. PMID:18765277

  10. HIV-1 protease inhibitor induced oxidative stress suppresses glucose stimulated insulin release: protection with thymoquinone.

    PubMed

    Chandra, Surabhi; Mondal, Debasis; Agrawal, Krishna C

    2009-04-01

    The highly active anti-retroviral therapy (HAART) regimen has considerably reduced the mortality rate in HIV-1 positive patients. However, long-term exposure to HAART is associated with a metabolic syndrome manifesting cardiovascular dysfunction, lipodystrophy, and insulin resistance syndrome (IRS). The inclusion of HIV-1 protease inhibitors (PIs) in HAART has been linked to the induction of IRS. Although several molecular mechanisms of PI-induced effects on insulin action have been postulated, the deleterious effects of PIs on insulin production by pancreatic beta-cells have not been fully investigated and therapeutic strategies to ameliorate insulin dysregulation at this level have not been targeted. The present study showed that exposure to several different PIs, nelfinavir (5-10 microM), saquinavir (5-10 microM) and atazanavir (8-20 microM), decreases glucose stimulated insulin secretion from rat pancreatic beta-cells (INS-1). Nelfinavir significantly increased reactive oxygen species (ROS) generation and suppressed cytosolic, but not mitochondrial superoxide dismutase (SOD) levels. Nelfinvair also decreased both glutathione and ATP and increased UCP2 levels in these cells. Simultaneous treatment with thymoquinone (TQ) (2.5 microM), an active ingredient of black seed oil, significantly inhibited the effect of nelfinavir on augmented ROS production and suppressed SOD levels. Both TQ and black seed oil exposure increased glucose stimulated insulin secretion and ameliorated the suppressive effect of nelfinavir. The present findings imply a direct role of ROS in PI induced deleterious effects on pancreatic beta-cells. Our findings also suggest that TQ may be used as a potential therapeutic agent to normalize the dysregulated insulin production observed in HAART treated patients.

  11. Di-peptidyl peptidase-4 inhibitor sitagliptin protects vascular function in metabolic syndrome: possible role of epigenetic regulation.

    PubMed

    Cicek, Figen Amber; Amber, Cicek Figen; Tokcaer-Keskin, Zeynep; Zeynep, Tokcaer-Keskin; Ozcinar, Evren; Evren, Ozcinar; Bozkus, Yosuf; Yusuf, Bozkus; Akcali, Kamil Can; Can, Akcali Kamil; Turan, Belma; Belma, Turan

    2014-08-01

    Metabolic syndrome (MetS) is a complex medical disorder characterized by insulin resistance, hypertension, and high risk of coronary disease and stroke. Microvascular rarefaction and endothelial dysfunction have also been linked with MetS, and recent evidence from clinical studies supports the efficacy of incretin-based antidiabetic therapies for vascular protection in diabetes. Previous studies pointed out the importance of dipeptidyl peptidase-4 (DPP-4) inhibition in endothelial cells due to getting protection against metabolic pathologies. We therefore aimed to investigate the acute effects of a DPP-4 inhibitor, sitagliptin, on vascular function in rats with high-sucrose diet-induced MetS. In order to elucidate the mechanisms implicated in the effects of DPP-4 inhibition, we tested the involvement of NO pathway and epigenetic regulation in the MetS. Acute use of sitagliptin protects the vascular function in the rats with MetS in part due to NO pathway via restoring the depressed aortic relaxation responses mediated by receptors. Application of sitagliptin enhanced the depressed phosphorylation levels of both the endothelial NO synthase and the apoptotic status of protein kinase B, known as Akt, in endothelium-intact thoracic aorta from rats with MetS. One-hour application of sitagliptin on aortic rings from rats with MetS also induced remarkable histon posttranslational modifications such as increased expression of H3K27Me3, but not of H3K27Me2, resulting in an accumulation of the H3K27Me3. Our findings suggest that, in addition to its well-known hypoglycemic action, sitagliptin may also have beneficial effects on hyperglycemia-induced vascular changes in an endotheium-dependent manner. These present results with sitagliptin aside from the glycaemic control, may demonstrate its important role in the treatment of patients with MetS.

  12. End-organ protection in hypertension by the novel and selective Rho-kinase inhibitor, SAR407899

    PubMed Central

    Löhn, Matthias; Plettenburg, Oliver; Kannt, Aimo; Kohlmann, Markus; Hofmeister, Armin; Kadereit, Dieter; Monecke, Peter; Schiffer, Alexander; Schulte, Anke; Ruetten, Hartmut; Ivashchenko, Yuri

    2015-01-01

    AIM: To compare the therapeutic efficacy of SAR407899 with the current standard treatment for hypertension [an angiotensin converting enzyme (ACE)-inhibitor and a calcium channel blocker] and compare the frequency and severity of the hypertension-related end-organ damage. METHODS: Long-term pharmacological characte-rization of SAR407899 has been performed in two animal models of hypertension, of which one is sensitive to ACE-inhibition (LNAME) and the other is insensitive [deoxycorticosterone acetate (DOCA)]. SAR407899 efficiently lowered high blood pressure and significantly reduced late-stage end organ damage as indicated by improved heart, kidney and endothelial function and reduced heart and kidney fibrosis in both models of chronic hypertension. RESULTS: Long term treatment with SAR407899 has been well tolerated and dose-dependently reduced elevated blood pressure in both models with no signs of tachyphylaxia. Blood pressure lowering effects and protective effects on hypertension related end organ damage of SAR407899 were superior to ramipril and amlodipine in the DOCA rat. Typical end-organ damage was significantly reduced in the SAR407899-treated animals. Chronic administration of SAR407899 significantly reduced albuminuria in both models. The beneficial effect of SAR407899 was associated with a reduction in leukocyte/macrophage tissue infiltration. The overall protective effect of SAR407899 was superior or comparable to that of ACE-inhibition or calcium channel blockade. Chronic application of SAR407899 protects against hypertension and hypertension-induced end organ damage, regardless of the pathophysiological mechanism of hypertension. CONCLUSION: Rho-kinases-inhibition by the SAR407899 represents a new therapeutic option for the treatment of hypertension and its complications. PMID:25632317

  13. Mesothelial glandular structures within pseudosarcomatous proliferative funiculitis--a diagnostic pitfall: report of 17 cases.

    PubMed

    Michal, Michal; Hes, Ondrej; Kazakov, Dmitry V

    2008-01-01

    We describe 17 cases of distinct benign pseudomalignant mesothelial proliferations, involving the spermatic cord. All cases revealed necrosis. The areas adjacent to the necrotic tissue comprised a cellular spindle cell proliferation with a haphazard arrangement of the myofibroblasts that in many areas revealed transitions into plump oval epithelioid cells and into cells with genuine epithelial appearances arranged in linear cords and often luminized into small microcysts. These epithelial cells formed isolated groups with glandular structures arising on the myofibroblastic background. Glandular structures were often situated deeply in the stroma of the spermatic cords. All cellular elements were strongly positive with AE1/AE3 antibody. All myofibroblasts stained with SM-actin antibody. Ultrastructurally, the spindle cells displayed features of myofibroblasts including actin microfilaments, as did the plump epithelioid cells that, additionally, had desmosomes, and the cords of the epithelial cells including those forming glandular structures had characteristics of mesothelias including the characteristic microvilli.

  14. Mesothelial-to-mesenchymal transition as a possible therapeutic target in peritoneal metastasis of ovarian cancer.

    PubMed

    Rynne-Vidal, Angela; Au-Yeung, Chi Lam; Jiménez-Heffernan, José A; Pérez-Lozano, María Luisa; Cremades-Jimeno, Lucía; Bárcena, Carmen; Cristóbal-García, Ignacio; Fernández-Chacón, Concepción; Yeung, Tsz Lun; Mok, Samuel C; Sandoval, Pilar; López-Cabrera, Manuel

    2017-03-01

    Peritoneal dissemination is the primary metastatic route of ovarian cancer (OvCa), and is often accompanied by the accumulation of ascitic fluid. The peritoneal cavity is lined by mesothelial cells (MCs), which can be converted into carcinoma-associated fibroblasts (CAFs) through mesothelial-to-mesenchymal transition (MMT). Here, we demonstrate that MCs isolated from ascitic fluid (AFMCs) of OvCa patients with peritoneal implants also undergo MMT and promote subcutaneous tumour growth in mice. RNA sequencing of AFMCs revealed that MMT-related pathways - including transforming growth factor (TGF)-β signalling - are differentially regulated, and a gene signature was verified in peritoneal implants from OvCa patients. In a mouse model, pre-induction of MMT resulted in increased peritoneal tumour growth, whereas interfering with the TGF-β receptor reduced metastasis. MC-derived CAFs showed activation of Smad-dependent TGF-β signalling, which was disrupted in OvCa cells, despite their elevated TGF-β production. Accordingly, targeting Smad-dependent signalling in the peritoneal pre-metastatic niche in mice reduced tumour colonization, suggesting that Smad-dependent MMT could be crucial in peritoneal carcinomatosis. Together, these results indicate that bidirectional communication between OvCa cells and MC-derived CAFs, via TGF-β-mediated MMT, seems to be crucial to form a suitable metastatic niche. We suggest MMT as a possible target for therapeutic intervention and a potential source of biomarkers for improving OvCa diagnosis and/or prognosis. © 2017 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of Pathological Society of Great Britain and Ireland.

  15. Size- and shape-dependent pleural translocation, deposition, fibrogenesis, and mesothelial proliferation by multiwalled carbon nanotubes.

    PubMed

    Xu, Jiegou; Alexander, David B; Futakuchi, Mitsuru; Numano, Takamasa; Fukamachi, Katsumi; Suzui, Masumi; Omori, Toyonori; Kanno, Jun; Hirose, Akihiko; Tsuda, Hiroyuki

    2014-07-01

    Multiwalled carbon nanotubes (MWCNT) have a fibrous structure similar to asbestos, raising concern that MWCNT exposure may lead to asbestos-like diseases. Previously we showed that MWCNT translocated from the lung alveoli into the pleural cavity and caused mesothelial proliferation and fibrosis in the visceral pleura. Multiwalled carbon nanotubes were not found in the parietal pleura, the initial site of development of asbestos-caused pleural diseases in humans, probably due to the short exposure period of the study. In the present study, we extended the exposure period to 24 weeks to determine whether the size and shape of MWCNT impact on deposition and lesion development in the pleura and lung. Two different MWCNTs were chosen for this study: a larger sized needle-like MWCNT (MWCNT-L; l = 8 μm, d = 150 nm), and a smaller sized MWCNT (MWCNT-S; l = 3 μm, d = 15 nm), which forms cotton candy-like aggregates. Both MWCNT-L and MWCNT-S suspensions were administered to the rat lung once every 2 weeks for 24 weeks by transtracheal intrapulmonary spraying. It was found that MWCNT-L, but not MWCNT-S, translocated into the pleural cavity, deposited in the parietal pleura, and induced fibrosis and patchy parietal mesothelial proliferation lesions. In addition, MWCNT-L induced stronger inflammatory reactions including increased inflammatory cell number and cytokine/chemokine levels in the pleural cavity lavage than MWCNT-S. In contrast, MWCNT-S induced stronger inflammation and higher 8-hydroxydeoxyguanosine level in the lung tissue than MWCNT-L. These results suggest that MWCNT-L has higher risk of causing asbestos-like pleural lesions relevant to mesothelioma development.

  16. Bleomycin induced epithelial–mesenchymal transition (EMT) in pleural mesothelial cells

    SciTech Connect

    Chen, Li-Jun; Ye, Hong; Zhang, Qian; Li, Feng-Zhi; Song, Lin-Jie; Yang, Jie; Mu, Qing; Rao, Shan-Shan; Cai, Peng-Cheng; Xiang, Fei; Zhang, Jian-Chu; Su, Yunchao; Xin, Jian-Bao; Ma, Wan-Li

    2015-03-01

    Idiopathic pulmonary fibrosis (IPF) is a chronic progressive lung disease characterized by the development of subpleural foci of myofibroblasts that contribute to the exuberant fibrosis. Recent studies revealed that pleural mesothelial cells (PMCs) undergo epithelial–mesenchymal transition (EMT) and play a pivotal role in IPF. In animal model, bleomycin induces pulmonary fibrosis exhibiting subpleural fibrosis similar to what is seen in human IPF. It is not known yet whether bleomycin induces EMT in PMCs. In the present study, PMCs were cultured and treated with bleomycin. The protein levels of collagen-I, mesenchymal phenotypic markers (vimentin and α-smooth muscle actin), and epithelial phenotypic markers (cytokeratin-8 and E-cadherin) were measured by Western blot. PMC migration was evaluated using wound-healing assay of culture PMCs in vitro, and in vivo by monitoring the localization of PMC marker, calretinin, in the lung sections of bleomycin-induced lung fibrosis. The results showed that bleomycin induced increases in collagen-I synthesis in PMC. Bleomycin induced significant increases in mesenchymal phenotypic markers and decreases in epithelial phenotypic markers in PMC, and promoted PMC migration in vitro and in vivo. Moreover, TGF-β1-Smad2/3 signaling pathway involved in the EMT of PMC was demonstrated. Taken together, our results indicate that bleomycin induces characteristic changes of EMT in PMC and the latter contributes to subpleural fibrosis. - Highlights: • Bleomycin induces collagen-I synthesis in pleural mesothelial cells (PMCs). • Bleomycin induces increases in vimentin and α-SMA protein in PMCs. • Bleomycin induces decreases in cytokeratin-8 and E-cadherin protein in PMCs • TGF-β1-Smad2/3 signaling pathway is involved in the PMC EMT induced by bleomycin.

  17. Size- and shape-dependent pleural translocation, deposition, fibrogenesis, and mesothelial proliferation by multiwalled carbon nanotubes

    PubMed Central

    Xu, Jiegou; Alexander, David B; Futakuchi, Mitsuru; Numano, Takamasa; Fukamachi, Katsumi; Suzui, Masumi; Omori, Toyonori; Kanno, Jun; Hirose, Akihiko; Tsuda, Hiroyuki

    2014-01-01

    Multiwalled carbon nanotubes (MWCNT) have a fibrous structure similar to asbestos, raising concern that MWCNT exposure may lead to asbestos-like diseases. Previously we showed that MWCNT translocated from the lung alveoli into the pleural cavity and caused mesothelial proliferation and fibrosis in the visceral pleura. Multiwalled carbon nanotubes were not found in the parietal pleura, the initial site of development of asbestos-caused pleural diseases in humans, probably due to the short exposure period of the study. In the present study, we extended the exposure period to 24 weeks to determine whether the size and shape of MWCNT impact on deposition and lesion development in the pleura and lung. Two different MWCNTs were chosen for this study: a larger sized needle-like MWCNT (MWCNT-L; l = 8 μm, d = 150 nm), and a smaller sized MWCNT (MWCNT-S; l = 3 μm, d = 15 nm), which forms cotton candy-like aggregates. Both MWCNT-L and MWCNT-S suspensions were administered to the rat lung once every 2 weeks for 24 weeks by transtracheal intrapulmonary spraying. It was found that MWCNT-L, but not MWCNT-S, translocated into the pleural cavity, deposited in the parietal pleura, and induced fibrosis and patchy parietal mesothelial proliferation lesions. In addition, MWCNT-L induced stronger inflammatory reactions including increased inflammatory cell number and cytokine/chemokine levels in the pleural cavity lavage than MWCNT-S. In contrast, MWCNT-S induced stronger inflammation and higher 8-hydroxydeoxyguanosine level in the lung tissue than MWCNT-L. These results suggest that MWCNT-L has higher risk of causing asbestos-like pleural lesions relevant to mesothelioma development. PMID:24815191

  18. Malignant pleural mesothelioma and mesothelial hyperplasia: A new molecular tool for the differential diagnosis.

    PubMed

    Bruno, Rossella; Alì, Greta; Giannini, Riccardo; Proietti, Agnese; Lucchi, Marco; Chella, Antonio; Melfi, Franca; Mussi, Alfredo; Fontanini, Gabriella

    2017-01-10

    Malignant pleural mesothelioma (MPM) is a rare asbestos related cancer, aggressive and unresponsive to therapies. Histological examination of pleural lesions is the gold standard of MPM diagnosis, although it is sometimes hard to discriminate the epithelioid type of MPM from benign mesothelial hyperplasia (MH).This work aims to define a new molecular tool for the differential diagnosis of MPM, using the expression profile of 117 genes deregulated in this tumour.The gene expression analysis was performed by nanoString System on tumour tissues from 36 epithelioid MPM and 17 MH patients, and on 14 mesothelial pleural samples analysed in a blind way. Data analysis included raw nanoString data normalization, unsupervised cluster analysis by Pearson correlation, non-parametric Mann Whitney U-test and molecular classification by the Uncorrelated Shrunken Centroid (USC) Algorithm.The Mann-Whitney U-test found 35 genes upregulated and 31 downregulated in MPM. The unsupervised cluster analysis revealed two clusters, one composed only of MPM and one only of MH samples, thus revealing class-specific gene profiles. The Uncorrelated Shrunken Centroid algorithm identified two classifiers, one including 22 genes and the other 40 genes, able to properly classify all the samples as benign or malignant using gene expression data; both classifiers were also able to correctly determine, in a blind analysis, the diagnostic categories of all the 14 unknown samples.In conclusion we delineated a diagnostic tool combining molecular data (gene expression) and computational analysis (USC algorithm), which can be applied in the clinical practice for the differential diagnosis of MPM.

  19. Protective effects of a squalene synthase inhibitor, lapaquistat acetate (TAK-475), on statin-induced myotoxicity in guinea pigs

    SciTech Connect

    Nishimoto, Tomoyuki; Ishikawa, Eiichiro; Anayama, Hisashi; Hamajyo, Hitomi; Nagai, Hirofumi; Hirakata, Masao; Tozawa, Ryuichi

    2007-08-15

    High-dose statin treatment has been recommended as a primary strategy for aggressive reduction of LDL cholesterol levels and protection against coronary artery disease. The effectiveness of high-dose statins may be limited by their potential for myotoxic side effects. There is currently little known about the molecular mechanisms of statin-induced myotoxicity. Previously we showed that T-91485, an active metabolite of the squalene synthase inhibitor lapaquistat acetate (lapaquistat: a previous name is TAK-475), attenuated statin-induced cytotoxicity in human skeletal muscle cells [Nishimoto, T., Tozawa, R., Amano, Y., Wada, T., Imura, Y., Sugiyama, Y., 2003a. Comparing myotoxic effects of squalene synthase inhibitor, T-91485, and 3-hydroxy-3-methylglutaryl coenzyme A. Biochem. Pharmacol. 66, 2133-2139]. In the current study, we investigated the effects of lapaquistat administration on statin-induced myotoxicity in vivo. Guinea pigs were treated with either high-dose cerivastatin (1 mg/kg) or cerivastatin together with lapaquistat (30 mg/kg) for 14 days. Treatment with cerivastatin alone decreased plasma cholesterol levels by 45% and increased creatine kinase (CK) levels by more than 10-fold (a marker of myotoxicity). The plasma CK levels positively correlated with the severity of skeletal muscle lesions as assessed by histopathology. Co-administration of lapaquistat almost completely prevented the cerivastatin-induced myotoxicity. Administration of mevalonolactone (100 mg/kg b.i.d.) prevented the cerivastatin-induced myotoxicity, confirming that this effect is directly related to HMG-CoA reductase inhibition. These results strongly suggest that cerivastatin-induced myotoxicity is due to depletion of mevalonate derived isoprenoids. In addition, squalene synthase inhibition could potentially be used clinically to prevent statin-induced myopathy.

  20. Genistein, the dietary-derived angiogenesis inhibitor, prevents LDL oxidation and protects endothelial cells from damage by atherogenic LDL.

    PubMed

    Kapiotis, S; Hermann, M; Held, I; Seelos, C; Ehringer, H; Gmeiner, B M

    1997-11-01

    There is now growing evidence that the oxidative modification of LDL plays a potential role in atherosclerosis. In this study, genistein, a compound derived from a soy diet with a flavonoid chemical structure (4',5,7-trihydroxyisoflavone), which was found to inhibit angiogenesis, has been evaluated for its ability to act as an LDL antioxidant and a vascular cell protective agent against oxidized LDL. The results showed that genistein was able to inhibit the oxidation of LDL in the presence of copper ions or superoxide/nitric oxide radicals as measured by thiobarbituric acid-reactive substance formation, alteration in electrophoretic mobility, and lipid hydroperoxides. Bovine aortic endothelial cell- and human endothelial cell-mediated LDL oxidation was also inhibited in the presence of genistein. The 7-O-glucoside of genistein, genistin, was much less effective in inhibiting LDL oxidation in the cell-free and cell-mediated lipoprotein-oxidating systems. Incubating human endothelial cells in the absence or presence of genistein and challenging the cells with already oxidized lipoprotein revealed that in addition to its antioxidative potential during LDL oxidating processes, genistein effectively protected the vascular cells from damage by oxidized lipoproteins. The tyrosine kinase inhibitor genistein was found to block upregulation of two tyrosine-phosphorylated proteins of 132 and 69 kDa in endothelial cells induced by oxidized LDL. Parallel experiments with the inactive analogue daidzein, however, showed that the cytoprotective effect of the isoflavones seems not to be dependent on tyrosine phosphorylation. Our findings will support the suggested and documented beneficial action of a soy diet in preventing chronic vascular diseases and early atherogenic events.

  1. Mitochondrial division inhibitor 1 protects against mutant huntingtin-induced abnormal mitochondrial dynamics and neuronal damage in Huntington's disease.

    PubMed

    Manczak, Maria; Reddy, P Hemachandra

    2015-12-20

    The objective of this study was to determine the protective effects of the mitochondrial division inhibitor 1 (Mdivi1) in striatal neurons that stably express mutant Htt (STHDhQ111/Q111) and wild-type (WT) Htt (STHDhQ7/Q7). Using gene expression analysis, biochemical methods, transmission electron microscopy (TEM) and confocal microscopy methods, we studied (i) mitochondrial and synaptic activities by measuring mRNA and the protein levels of mitochondrial and synaptic genes, (ii) mitochondrial function and (iii) ultra-structural changes in mutant Htt neurons relative to WT Htt neurons. We also studied these parameters in Mdivil-treated and untreated WT and mutant Htt neurons. Increased expressions of mitochondrial fission genes, decreased expression of fusion genes and synaptic genes were found in the mutant Htt neurons relative to the WT Htt neurons. Electron microscopy of the mutant Htt neurons revealed a significantly increased number of mitochondria, indicating that mutant Htt fragments mitochondria. Biochemical analysis revealed defective mitochondrial functioning. In the Mdivil-treated mutant Htt neurons, fission genes were down-regulated, and fusion genes were up-regulated, suggesting that Mdivil decreases fission activity. Synaptic genes were up-regulated, and mitochondrial function was normal in the Mdivi1-treated mutant Htt neurons. Immunoblotting findings of mitochondrial and synaptic proteins agreed with mRNA findings. The TEM studies revealed that increased numbers of structurally intact mitochondria were present in Mdivi1-treated mutant Htt neurons. Increased synaptic and mitochondrial fusion genes and decreased fission genes were found in the Mdivi1-treated WT Htt neurons, indicating that Mdivi1 beneficially affects healthy neurons. Taken together, these findings suggest that Mdivi1 is protective against mutant Htt-induced mitochondrial and synaptic damage in HD neurons and that Mdivi1 may be a promising molecule for the treatment of HD patients.

  2. Nebivolol, a β1-adrenergic blocker, protects from peritoneal membrane damage induced during peritoneal dialysis

    PubMed Central

    Abensur, Hugo; Albar-Vizcaino, Patricia; Parra, Emilio González; Sandoval, Pilar; Ramírez, Laura García; del Peso, Gloria; Acedo, Juan Manuel; Bajo, María A.; Selgas, Rafael; Tomero, José A. Sánchez; López-Cabrera, Manuel; Aguilera, Abelardo

    2016-01-01

    Peritoneal dialysis (PD) is a form of renal replacement treatment, which employs the peritoneal membrane (PM) to eliminate toxins that cannot be removed by the kidney. The procedure itself, however, contributes to the loss of the PM ultrafiltration capacity (UFC), leading consequently to the technique malfunction. β-blockers have been considered deleterious for PM due to their association with loss of UFC and induction of fibrosis. Herein we analyzed the effects of Nebivolol, a new generation of β1-blocker, on PM alterations induced by PD fluids (PDF). In vitro: We found that mesothelial cells (MCs) express β1-adrenergic receptor. MCs were treated with TGF-β to induce mesothelial-to-mesenchymal transition (MMT) and co-treated with Nebivolol. Nebivolol reversed the TGF-β effects, decreasing extracellular matrix synthesis, and improved the fibrinolytic capacity, decreasing plasminogen activator inhibitor-1 (PAI-1) and increasing tissue-type plasminogen activator (tPA) supernatant levels. Moreover, Nebivolol partially inhibited MMT and decreased vascular endothelial growth factor (VEGF) and IL-6 levels in supernatants. In vivo: Twenty-one C57BL/6 mice were divided into 3 groups. Control group carried a catheter without PDF infusion. Study group received intraperitoneally PDF and oral Nebivolol during 30 days. PDF group received PDF alone. Nebivolol maintained the UFC and reduced PM thickness, MMT and angiogenesis promoted by PDF. It also improved the fibrinolytic capacity in PD effluents decreasing PAI-1 and IL-8 and increased tPA levels. Conclusion: Nebivolol protects PM from PDF-induced damage, promoting anti-fibrotic, anti-angiogenic, anti-inflammatory and pro-fibrinolytic effects. PMID:27102153

  3. Structural optimization of a retrograde trafficking inhibitor that protects cells from infections by human polyoma- and papillomaviruses.

    PubMed

    Carney, Daniel W; Nelson, Christian D S; Ferris, Bennett D; Stevens, Julia P; Lipovsky, Alex; Kazakov, Teymur; DiMaio, Daniel; Atwood, Walter J; Sello, Jason K

    2014-09-01

    Human polyoma- and papillomaviruses are non-enveloped DNA viruses that cause severe pathologies and mortalities. Under circumstances of immunosuppression, JC polyomavirus causes a fatal demyelinating disease called progressive multifocal leukoencephalopathy (PML) and the BK polyomavirus is the etiological agent of polyomavirus-induced nephropathy and hemorrhagic cystitis. Human papillomavirus type 16, another non-enveloped DNA virus, is associated with the development of cancers in tissues like the uterine cervix and oropharynx. Currently, there are no approved drugs or vaccines to treat or prevent polyomavirus infections. We recently discovered that the small molecule Retro-2(cycl), an inhibitor of host retrograde trafficking, blocked infection by several human and monkey polyomaviruses. Here, we report diversity-oriented syntheses of Retro-2(cycl) and evaluation of the resulting analogs using an assay of human cell infections by JC polyomavirus. We defined structure-activity relationships and also discovered analogs with significantly improved potency as suppressors of human polyoma- and papillomavirus infection in vitro. Our findings represent an advance in the development of drug candidates that can broadly protect humans from non-enveloped DNA viruses and toxins that exploit retrograde trafficking as a means for cell entry.

  4. Proton pump inhibitors protect mice from acute systemic inflammation and induce long-term cross-tolerance

    PubMed Central

    Balza, E; Piccioli, P; Carta, S; Lavieri, R; Gattorno, M; Semino, C; Castellani, P; Rubartelli, A

    2016-01-01

    Incidence of sepsis is increasing, representing a tremendous burden for health-care systems. Death in acute sepsis is attributed to hyperinflammatory responses, but the underlying mechanisms are still unclear. We report here that proton pump inhibitors (PPIs), which block gastric acid secretion, selectively inhibited tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β) secretion by Toll-like receptor (TLR)-activated human monocytes in vitro, in the absence of toxic effects. Remarkably, the oversecretion of IL-1β that represents a hallmark of monocytes from patients affected by cryopyrin-associated periodic syndrome is also blocked. Based on these propaedeutic experiments, we tested the effects of high doses of PPIs in vivo in the mouse model of endotoxic shock. Our data show that a single administration of PPI protected mice from death (60% survival versus 5% of untreated mice) and decreased TNF-α and IL-1β systemic production. PPIs were efficacious even when administered after lipopolysaccharide (LPS) injection. PPI-treated mice that survived developed a long-term cross-tolerance, becoming resistant to LPS- and zymosan-induced sepsis. In vitro, their macrophages displayed impaired TNF-α and IL-1β to different TLR ligands. PPIs also prevented sodium thioglycollate-induced peritoneal inflammation, indicating their efficacy also in a non-infectious setting independent of TLR stimulation. Lack of toxicity and therapeutic effectiveness make PPIs promising new drugs against sepsis and other severe inflammatory conditions. PMID:27441656

  5. Structural Optimization of a Retrograde Trafficking Inhibitor that Protects Cells from Infections by Human Polyoma- and Papillomaviruses

    PubMed Central

    Carney, Daniel W.; Nelson, Christian D. S.; Ferris, Bennett D.; Stevens, Julia P.; Lipovsky, Alex; Kazakov, Temur; DiMaio, Daniel C.; Atwood, Walter J.; Sello, Jason K.

    2015-01-01

    Human polyoma- and papillomaviruses are non-enveloped DNA viruses that cause severe pathologies and mortalities. Under circumstances of immunosuppression, JC polyomavirus causes a fatal demyelinating disease called progressive multifocal leukoencephalopathy (PML) and the BK polyomavirus is the etiological agent of polyomavirus-induced nephropathy and hemorrhagic cystitis. Human papillomavirus type 16, another non-enveloped DNA virus, is associated with the development of cancers in tissues like the uterine cervix and oropharynx. Currently, there are no approved drugs or vaccines to treat or prevent polyomavirus infections. We recently discovered that the small molecule Retro-2cycl, an inhibitor of host retrograde trafficking, blocked infection by several human and monkey polyomaviruses. Here, we report diversity-oriented syntheses of Retro-2cycl and evaluation of the resulting analogs using an assay of human cell infections by JC polyomavirus. We defined structure-activity relationships and also discovered analogs with significantly improved potency as suppressors of human polyoma- and papillomavirus infection in vitro. Our findings represent an advance in the development of drug candidates that can broadly protect humans from non-enveloped DNA viruses and toxins that exploit retrograde trafficking as a means for cell entry. PMID:25087050

  6. Protective mechanism of the Mexican bean weevil against high levels of alpha-amylase inhibitor in the common bean.

    PubMed

    Ishimoto, M; Chrispeels, M J

    1996-06-01

    Alpha-amylase inhibitor (alpha AI) protects seeds of the common bean (Phaseolus vulgaris) against predation by certain species of bruchids such as the cowpea weevil (Callosobruchus maculatus) and the azuki bean weevil (Callosobruchus chinensis), but not against predation by the bean weevil (Acanthoscelides obtectus) or the Mexican bean weevil (Zabrotes subfasciatus), insects that are common in the Americas. We characterized the interaction of alpha AI-1 present in seeds of the common bean, of a different isoform, alpha AI-2, present in seeds of wild common bean accessions, and of two homologs, alpha AI-Pa present in seeds of the tepary bean (Phaseolus acutifolius) and alpha AI-Pc in seeds of the scarlet runner bean (Phaseolus coccineus), with the midgut extracts of several bruchids. The extract of the Z. subfasciatus larvae rapidly digests and inactivates alpha AI-1 and alpha AI-Pc, but not alpha AI-2 or alpha AI-Pa. The digestion is caused by a serine protease. A single proteolytic cleavage in the beta subunit of alpha AI-1 occurs at the active site of the protein. When degradation is prevented, alpha AI-1 and alpha AI-Pc do not inhibit the alpha-amylase of Z. subfasciatus, although they are effective against the alpha-amylase of C. chinensis. Alpha AI-2 and alpha AI-Pa, on the other hand, do inhibit the alpha-amylase of Z. subfasciatus, suggesting that they are good candidates for genetic engineering to achieve resistance to Z. subfasciatus.

  7. HDAC Inhibitor-Mediated Beta-Cell Protection Against Cytokine-Induced Toxicity Is STAT1 Tyr701 Phosphorylation Independent

    PubMed Central

    Dahllöf, Mattias S.; Christensen, Dan P.; Harving, Mette; Wagner, Bridget K.; Mandrup-Poulsen, Thomas

    2015-01-01

    Histone deacetylase (HDAC) inhibition protects pancreatic beta-cells against apoptosis induced by the combination of the proinflammatory cytokines interleukin (IL)-1β and interferon (IFN)-γ. Decreased expression of cell damage-related genes is observed on the transcriptional level upon HDAC inhibition using either IL-1β or IFN-γ alone. Whereas HDAC inhibition has been shown to regulate NFκB-activity, related primarily to IL-1β signaling, it is unknown whether the inhibition of HDACs affect IFN-γ signaling in beta-cells. Further, in non-beta-cells, there is a dispute whether HDAC inhibition regulates IFN-γ signaling at the level of STAT1 Tyr701 phosphorylation. Using different small molecule HDAC inhibitors with varying class selectivity, INS-1E wild type and stable HDAC1-3 knockdown pancreatic INS-1 cell lines, we show that IFN-γ-induced Cxcl9 and iNos expression as well as Cxcl9 and GAS reporter activity were decreased by HDAC inhibition in a STAT1 Tyr701 phosphorylation-independent fashion. In fact, knockdown of HDAC1 increased IFN-γ-induced STAT1 phosphorylation. PMID:25062500

  8. Mesothelial/monocytic incidental cardiac excrescences (cardiac MICE) associated with acute aortic dissection: a study of two cases

    PubMed Central

    Strecker, Thomas; Bertz, Simone; Wachter, David Lukas; Weyand, Michael; Agaimy, Abbas

    2015-01-01

    Acute aortic dissection is a life-threatening condition mainly caused by hypertension, atherosclerotic disease and other degenerative diseases of the connective tissue of the aortic wall. Mesothelial/monocytic incidental cardiac excrescences (cardiac MICE) is a rare benign reactive tumor-like lesion composed of admixture of histiocytes, mesothelial cells, and inflammatory cells set within a fibrinous meshwork without a vascular network or supporting stroma. Cardiac MICE occurring in association with aortic dissection is exceptionally rare (only one such case reported to date). We herein report on the surgical repair of two Stanford type A aortic dissections caused by idiopathic giant cell aortitis in a 66-year-old-woman and by atherosclerotic disease in a 58-year-old-man, respectively. In both cases, the dissections could be visualized via computed tomography. Histopathology showed cardiac incidental MICE within the external aortic wall near the pericardial surface which was confirmed by immunohistochemistry. PMID:26097568

  9. Estrogen Receptor Alpha Is Expressed in Mesenteric Mesothelial Cells and Is Internalized in Caveolae upon Freund's Adjuvant Treatment

    PubMed Central

    Balogh, Petra; Szabó, Arnold; Katz, Sándor; Likó, István; Patócs, Attila; L.Kiss, Anna

    2013-01-01

    Transformation of epithelial cells into connective tissue cells (epithelial-mesenchymal transition, EMT) is a complex mechanism involved in tumor metastasis, and in normal embryogenesis, while type II EMT is mainly associated with inflammatory events and tissue regenaration. In this study we examined type II EMT at the ultrastructural and molecular level during the inflammatory process induced by Freund's adjuvant treatment in rat mesenteric mesothelial cells. We found that upon the inflammatory stimulus mesothelial cells lost contact with the basal lamina and with each other, and were transformed into spindle-shaped cells. These morphological changes were accompanied by release of interleukins IL-1alpha, -1beta and IL-6 and by secretion of transforming growth factor beta (TGF-β) into the peritoneal cavity. Mesothelial cells also expressed estrogen receptor alpha (ER-α) as shown by immunolabeling at the light and electron microscopical levels, as well as by quantitative RT-PCR. The mRNA level of ER-α showed an inverse correlation with the secretion of TGF-β. At the cellular and subcellular levels ER-α was colocalized with the coat protein caveolin-1 and was found in the plasma membrane of mesothelial cells, in caveolae close to multivesicular bodies (MVBs) or in the membrane of these organelles, suggesting that ER-α is internalized via caveola-mediated endocytosis during inflammation. We found asymmetric, thickened, electron dense areas on the limiting membrane of MVBs (MVB plaques) indicating that these sites may serve as platforms for collecting and organizing regulatory proteins. Our morphological observations and biochemical data can contribute to form a potential model whereby ER-α and its caveola-mediated endocytosis might play role in TGF-β induced type II EMT in vivo. PMID:24244516

  10. Characterization of preneoplastic and neoplastic rat mesothelial cell lines: the involvement of TETs, DNMTs, and 5-hydroxymethylcytosine.

    PubMed

    Roulois, David; Deshayes, Sophie; Guilly, Marie-Noëlle; Nader, Joëlle S; Liddell, Charly; Robard, Myriam; Hulin, Philippe; Ouacher, Amal; Le Martelot, Vanessa; Fonteneau, Jean-François; Grégoire, Marc; Blanquart, Christophe; Pouliquen, Daniel L

    2016-06-07

    Malignant mesothelioma (MM) is one of the worst cancers in terms of clinical outcome, urging the need to establish and characterize new preclinical tools for investigation of the tumorigenic process, improvement of early diagnosis and evaluation of new therapeutic strategies. For these purposes, we characterized a collection of 27 cell lines established from F344 rats, after 136 to 415 days of induction with crocidolite asbestos administered intraperitoneally. Four mesotheliomas were distinguished from 23 preneoplastic mesothelial cell lines (PN) according to their propensity to generate tumors after orthotopic transplantation into syngeneic rats, their growth pattern, and the expression profile of three genes. PN cell lines were further discriminated into groups / subgroups according to morphology in culture and the expression profiles of 14 additional genes. This approach was completed by analysis of positive and negative immunohistochemical MM markers in the four tumors, of karyotype alterations in the most aggressive MM cell line in comparison with a PN epithelioid cell line, and of human normal mesothelial and mesothelioma cells and a tissue array. Our results showed that both the rat and human MM cell lines shared in common a dramatic decrease in the relative expression of Cdkn2a and of epigenetic regulators, in comparison with PN and normal human mesothelial cells, respectively. In particular, we identified the involvement of the relative expression of the Ten-Eleven Translocation (TET) family of dioxygenases and Dnmt3a in relation to the 5-hydroxymethylcytosine level in malignant transformation and the acquisition of metastatic potential.

  11. Distinguishing benign from malignant mesothelial cells in effusions by Glut-1, EMA, and Desmin expression: an evidence-based approach.

    PubMed

    Kuperman, Michael; Florence, Roxanne R; Pantanowitz, Liron; Visintainer, Paul F; Cibas, Edmund S; Otis, Christopher N

    2013-02-01

    Distinguishing malignant mesothelioma (MM) from reactive mesothelial hyperplasia (RM) may be difficult in effusions. This study tested the hypothesis that immunocytochemistry (IC) in effusion cell blocks (CB) can distinguish MM from RM and that the results may be applied to individual specimens. External validation of a risk score (RS) model associating sensitivity and specificity was applied to an external set of MM and RM specimens from a separate institution. Forty three effusion cytology CBs of 25 confirmed malignant mesotheliomas were compared to CBs of 23 benign mesothelial effusions without inflammation and 13 reactive mesothelial proliferations associated with inflammation. Glut-1, EMA, and Desmin expression were evaluated by immunocytochemistry on CBs. Each antibody was compared using ROC values, where the area under the curve (AUC) was 0.90, 0.82, and 0.84 for Glut-1, EMA, and Desmin, respectively. Logistic regression (LR) analysis was applied to a combination of Glut-1 and EMA. A combined ROC curve was modeled for Glut-1 and EMA (AUC = 0.93). A RS = 2 × (Glut-1%) + 1 × (EMA%) was created from this ROC curve. When applied to an external set of MM and RM, the RS resulted in an ROC with AUC = 0.91. In conclusion, a RS derived from a LR of Glut-1 and EMA IC greatly improves the distinction between MM from RM cells in individual effusions. The study illustrates principles of evidence-based pathology concerning internal and external test performance in the differential diagnosis of MM versus RM.

  12. Characterization of preneoplastic and neoplastic rat mesothelial cell lines: the involvement of TETs, DNMTs, and 5-hydroxymethylcytosine

    PubMed Central

    Roulois, David; Deshayes, Sophie; Guilly, Marie-Noëlle; Nader, Joëlle S.; Liddell, Charly; Robard, Myriam; Hulin, Philippe; Ouacher, Amal; Le Martelot, Vanessa; Fonteneau, Jean-François; Grégoire, Marc

    2016-01-01

    Malignant mesothelioma (MM) is one of the worst cancers in terms of clinical outcome, urging the need to establish and characterize new preclinical tools for investigation of the tumorigenic process, improvement of early diagnosis and evaluation of new therapeutic strategies. For these purposes, we characterized a collection of 27 cell lines established from F344 rats, after 136 to 415 days of induction with crocidolite asbestos administered intraperitoneally. Four mesotheliomas were distinguished from 23 preneoplastic mesothelial cell lines (PN) according to their propensity to generate tumors after orthotopic transplantation into syngeneic rats, their growth pattern, and the expression profile of three genes. PN cell lines were further discriminated into groups / subgroups according to morphology in culture and the expression profiles of 14 additional genes. This approach was completed by analysis of positive and negative immunohistochemical MM markers in the four tumors, of karyotype alterations in the most aggressive MM cell line in comparison with a PN epithelioid cell line, and of human normal mesothelial and mesothelioma cells and a tissue array. Our results showed that both the rat and human MM cell lines shared in common a dramatic decrease in the relative expression of Cdkn2a and of epigenetic regulators, in comparison with PN and normal human mesothelial cells, respectively. In particular, we identified the involvement of the relative expression of the Ten-Eleven Translocation (TET) family of dioxygenases and Dnmt3a in relation to the 5-hydroxymethylcytosine level in malignant transformation and the acquisition of metastatic potential. PMID:27129173

  13. A long-acting integrase inhibitor protects female macaques from repeated high-dose intravaginal SHIV challenge.

    PubMed

    Andrews, Chasity D; Yueh, Yun Lan; Spreen, William R; St Bernard, Leslie; Boente-Carrera, Mar; Rodriguez, Kristina; Gettie, Agegnehu; Russell-Lodrigue, Kasi; Blanchard, James; Ford, Susan; Mohri, Hiroshi; Cheng-Mayer, Cecilia; Hong, Zhi; Ho, David D; Markowitz, Martin

    2015-01-14

    Long-acting GSK1265744 (GSK744 LA) is a strand transfer inhibitor of the HIV/SIV (simian immunodeficiency virus) integrase and was shown to be an effective preexposure prophylaxis (PrEP) agent in a low-dose intrarectal SHIV (simian-human immunodeficiency virus) rhesus macaque challenge model. We examined the pharmacokinetics and efficacy of GSK744 LA as PrEP against repeat high-dose intravaginal SHIV challenge in female rhesus macaques treated with Depo-Provera (depot medroxyprogesterone acetate), which promotes viral transmission vaginally. When Depo-Provera-treated female rhesus macaques were dosed with GSK744 LA (50 mg/kg) monthly, systemic and tissue drug concentrations were lower than previously observed in male rhesus macaques. GSK744 concentrations were fivefold lower on average in cervical tissues than in rectal tissues. Eight female rhesus macaques were treated with GSK744 LA at week 0, and four female rhesus macaques served as controls. All animals received a high-dose challenge of SHIV162P3 at week 1. No infection was detected in GSK744 LA-treated rhesus macaques, whereas viremia was detected 1 to 2 weeks after SHIV challenge in all control animals. The GSK744 LA-treated rhesus macaques were given a second administration of drug at week 4 and further challenged at weeks 5 and 7. GSK744 LA treatment protected six of eight female rhesus macaques against three high-dose SHIV challenges, whereas all control animals became infected after the first challenge (P = 0.0003, log-rank test). These results support further clinical development of GSK744 LA for PrEP.

  14. Transition of Mesothelial Cell to Fibroblast in Peritoneal Dialysis: EMT, Stem Cell or Bystander?

    PubMed Central

    Liu, Yu; Dong, Zheng; Liu, Hong; Zhu, Jiefu; Liu, Fuyou; Chen, Guochun

    2015-01-01

    Long-term peritoneal dialysis (PD) can lead to fibrotic changes in the peritoneum, characterized by loss of mesothelial cells (MCs) and thickening of the submesothelial area with an accumulation of collagen and myofibroblasts. The origin of myofibroblasts is a central question in peritoneal fibrosis that remains unanswered at present. Numerous clinical and experimental studies have suggested that MCs, through epithelial-mesenchymal transition (EMT), contribute to the pool of peritoneal myofibroblasts. However, recent work has placed significant doubts on the paradigm of EMT in organ fibrogenesis (in the kidney particularly), highlighting the need to reconsider the role of EMT in the generation of myofibroblasts in peritoneal fibrosis. In particular, selective cell isolation and lineage-tracing experiments have suggested the existence of progenitor cells in the peritoneum, which are able to switch to fibroblast-like cells when stimulated by the local environment. These findings highlight the plastic nature of MCs and its contribution to peritoneal fibrogenesis. In this review, we summarize the key findings and caveats of EMT in organ fibrogenesis, with a focus on PD-related peritoneal fibrosis, and discuss the potential of peritoneal MCs as a source of myofibroblasts. PMID:25700459

  15. Activation of calpain by renin-angiotensin system in pleural mesothelial cells mediates tuberculous pleural fibrosis

    PubMed Central

    Yang, Jie; Xiang, Fei; Cai, Peng-Cheng; Lu, Yu-Zhi; Xu, Xiao-Xiao; Yu, Fan; Li, Feng-Zhi; Greer, Peter A.; Shi, Huan-Zhong; Zhou, Qiong; Xin, Jian-Bao; Ye, Hong; Su, Yunchao

    2016-01-01

    Pleural fibrosis is defined as an excessive deposition of extracellular matrix (ECM) components that results in destruction of the normal pleural tissue architecture. It can result from diverse inflammatory conditions, especially tuberculous pleurisy. Pleural mesothelial cells (PMCs) play a pivotal role in pleural fibrosis. Calpain is a family of calcium-dependent endopeptidases, which plays an important role in ECM remodeling. However, the role of calpain in pleural fibrosis remains unknown. In the present study, we found that tuberculous pleural effusion (TPE) induced calpain activation in PMCs and that inhibition of calpain prevented TPE-induced collagen-I synthesis and cell proliferation of PMCs. Moreover, our data revealed that the levels of angiotensin (ANG)-converting enzyme (ACE) were significantly higher in pleural fluid of patients with TPE than those with malignant pleural effusion, and ACE-ANG II in TPE resulted in activation of calpain and subsequent triggering of the phosphatidylinositol 3-kinase (PI3K)/Akt/NF-κB signaling pathway in PMCs. Finally, calpain activation in PMCs and collagen depositions were confirmed in pleural biopsy specimens from patients with tuberculous pleurisy. Together, these studies demonstrated that calpain is activated by renin-angiotensin system in pleural fibrosis and mediates TPE-induced collagen-I synthesis and proliferation of PMCs via the PI3K/Akt/NF-κB signaling pathway. Calpain in PMCs might be a novel target for intervention in tuberculous pleural fibrosis. PMID:27261452

  16. The diagnostic utility of p16 FISH and GLUT-1 immunohistochemical analysis in mesothelial proliferations.

    PubMed

    Monaco, Sara E; Shuai, Yongli; Bansal, Mona; Krasinskas, Alyssa M; Dacic, Sanja

    2011-04-01

    Two promising ancillary tests used in the diagnosis of mesothelioma include GLUT-1 immunohistochemical analysis and fluorescence in situ hybridization (FISH) testing for the p16 deletion. This study compared the diagnostic usefulness of p16 FISH and GLUT-1 immunohistochemical analysis in the diagnosis of mesothelial proliferations in 158 cases with a diagnosis of benign (45.4%), atypical (10.4%), or malignant/mesothelioma (44.2%). Of the 70 benign cases, none had a deletion of p16 and 5 cases (7%) were positive for GLUT-1. Of the 68 mesotheliomas, 40 (59%) had a deletion of p16 (sensitivity, 59%; specificity, 100%) and 27 (40%) were positive for GLUT-1 (sensitivity, 40%; specificity, 93%). GLUT-1 showed lower sensitivity in pleural (56% vs 70%) and peritoneal (29% vs 51%) mesotheliomas (P = .004). Our results demonstrate that p16 FISH is a more sensitive and specific test than GLUT-1 immunohistochemical analysis and can be a more reliable ancillary tool to support the diagnosis of mesothelioma.

  17. The Role of Mesothelial Cells in Liver Development, Injury, and Regeneration.

    PubMed

    Lua, Ingrid; Asahina, Kinji

    2016-03-01

    Mesothelial cells (MCs) cover the surface of visceral organs and the parietal walls of cavities, and they synthesize lubricating fluids to create a slippery surface that facilitates movement between organs without friction. Recent studies have indicated that MCs play active roles in liver development, fibrosis, and regeneration. During liver development, the mesoderm produces MCs that form a single epithelial layer of the mesothelium. MCs exhibit an intermediate phenotype between epithelial cells and mesenchymal cells. Lineage tracing studies have indicated that during liver development, MCs act as mesenchymal progenitor cells that produce hepatic stellate cells, fibroblasts around blood vessels, and smooth muscle cells. Upon liver injury, MCs migrate inward from the liver surface and produce hepatic stellate cells or myofibroblast depending on the etiology, suggesting that MCs are the source of myofibroblasts in capsular fibrosis. Similar to the activation of hepatic stellate cells, transforming growth factor β induces the conversion of MCs into myofibroblasts. Further elucidation of the biological and molecular changes involved in MC activation and fibrogenesis will contribute to the development of novel approaches for the prevention and therapy of liver fibrosis.

  18. Phosphodiesterase-5 Inhibitor, Tadalafil, Protects against Myocardial Ischemia/Reperfusion through Protein-Kinase G Dependent Generation of Hydrogen Sulfide

    PubMed Central

    Salloum, Fadi N.; Chau, Vinh Q.; Hoke, Nicholas N.; Abbate, Antonio; Varma, Amit; Ockaili, Ramzi A.; Toldo, Stefano; Kukreja, Rakesh C.

    2014-01-01

    Background Tadalafil is a novel long acting inhibitor of phosphodiesterase-5. Since cGMP-dependent protein kinase (PKG) signaling plays a key role in cardioprotection, we hypothesized that PKG activation with tadalafil would limit myocardial ischemia/reperfusion (I/R) injury and dysfunction. Additionally, we contemplated that cardioprotection with tadalafil is mediated by hydrogen sulfide (H2S) signaling in a PKG-dependent fashion. Methods and Results After baseline transthoracic echocardiography (TTE), adult ICR mice were injected i.p. with vehicle (10% DMSO) or tadalafil (1 mg/kg) with or without KT5823 (KT, PKG blocker, 1 mg/kg) or dl-propargylglycine [PAG, Cystathionine-γ-lyase (CSE, H2S-producing enzyme) blocker; 50 mg/kg] 1 h prior to coronary artery ligation for 30 min and reperfusion for 24 h, whereas C57BL-wild type and CSE-knockout mice were treated with either vehicle or tadalafil. After reperfusion, TTE was performed and hearts were collected for infarct size (IS) measurement using TTC staining. Survival was increased with tadalafil (95%) compared with control (65%, P<0.05). Infarct size was reduced with tadalafil (13.2±1.7%) compared to vehicle (40.6±2.5%; P<0.05). KT and PAG abolished tadalafil-induced protection (IS: 39.2±1% and 51.2±2.4%, respectively) similar to genetic deletion of CSE (47.2±5.1%). Moreover, tadalafil preserved fractional shortening (FS: 31±1.5%) compared to control (FS: 22±4.8%, P<0.05). Baseline FS was 44±1.7%. KT and PAG abrogated the preservation of LV function with tadalafil by a decline in FS to 17±1% and 23±3%, respectively. Compared to vehicle, myocardial H2S production was significantly increased with tadalafil and was abolished with KT. Conclusion PKG activation with tadalafil limits myocardial infarction and preserves LV function through H2S signaling. PMID:19752383

  19. Molecular Mechanism of Silver Nanoparticles-Induced Human Osteoblast Cell Death: Protective Effect of Inducible Nitric Oxide Synthase Inhibitor

    PubMed Central

    Zielinska, Ewelina; Tukaj, Cecylia; Radomski, Marek Witold; Inkielewicz-Stepniak, Iwona

    2016-01-01

    Background Silver nanoparticles (AgNPs) show strong antibacterial properties, making them excellent candidates to be used in orthopaedic repair and regeneration. However, there are concerns regarding the cytotoxicity of AgNPs and molecular mechanisms underlying AgNPs-induced bone cells toxicity have not been elucidated. Therefore, the aim of our study was to explore mechanisms of AgNPs-induced osteoblast cell death with particular emphasis on the role of nitric oxide (NO) generated by inducible nitric oxide synthase (iNOS). Methods and Result Silver nanoparticles used in this study were 18.3±2.6 nm in size, uncoated, spherical, regular shape and their zeta potential was -29.1±2.4 mV as measured by transmission electron microscopy (TEM) and zetasizer. The release of silver (Ag) from AgNPs was measured in cell culture medium by atomic absorption spectroscopy (AAS). The exposure of human osteoblast cells (hFOB 1.19) to AgNPs at concentration of 30 or 60 μg/mL for 24 or 48 hours, respectively resulted in cellular uptake of AgNPs and changes in cell ultrastructure. These changes were associated with apoptosis and necrosis as shown by flow cytometry and lactate dehydrogenase (LDH) assay as well as increased levels of pro-apoptotic Bax and decreased levels of anti-apoptotic Bcl-2 mRNA and protein. Importantly, we have found that AgNPs elevated the levels of nitric oxide (NO) with concomitant upregulation of inducible nitric oxide synthase (iNOS) mRNA and protein. A significant positive correlation was observed between the concentration of AgNPs and iNOS at protein and mRNA level (r = 0.837, r = 0.721, respectively; p<0.001). Finally, preincubation of osteoblast cells with N-iminoethyl-l-lysine (L-NIL), a selective iNOS inhibitor, as well as treating cells with iNOS small interfering RNAs (siRNA) significantly attenuated AgNPs-induced apoptosis and necrosis. Moreover, we have found that AgNPs-induced cells death is not related to Ag dissolution is cell culture medium

  20. Nuclear Factor kB and Inhibitor of kB: Acupuncture Protection Against Acute Focal Cerebral Ischemia in Rodents.

    PubMed

    Huang, Wei; Zhou, Zhongyu; Wan, Bijiang; Chen, Guang; Li, Jia

    2017-02-27

    Context • Acute, focal, cerebral ischemic stroke is a leading cause of morbidity and mortality worldwide. Acupuncture is an emerging alternative therapy for treatment of acute brain ischemia. Nevertheless, the precise mechanism underlying the neuroprotective effects of acupuncture has not been elucidated. Nuclear factor κB (NF-κB) and nuclear factor of κ light polypeptide gene enhancer in B cell inhibitor alpha (IκB-α) are involved in cerebral inflammation. However, the involvement of NF-κB and IκB-α in the protective effects of acupuncture on ischemic tolerance remains unknown. Objective • The study evaluated the hypothesis that acupuncture can exert a neuroprotective action in a rat model of middle cerebral artery occlusion (MCAO). Design • The rats were randomly divided into a normal group (N), a sham model group (SM), an MCAO model group (M), a sham acupuncture group (SA), and an acupuncture group (A). Setting • All of processes of this study were conducted at Hubei University of Chinese Medicine (Hubei Shang, China). Animals • The animals were 100 Sprague-Dawley rats, aged 3 mo. Intervention • Craniotomy and electrocoagulation of the middle cerebral artery were conducted to generate acute, focal, cerebral ischemic models in 3 groups, excluding the N and SM groups. The SM group received a surgical fenestration similar to the M group, but the procedure did not include the coagulation of the exposed artery. In the A group, acupuncture was administered at the acupoints Baihui (GV-20) and Renzhong (GV-26). In the SA group, sham acupuncture was performed at a depth of 5 mm at a position close to the left side of the GV-20 and GV-26 points. The N, M, and SM groups received neither the acupuncture nor the sham acupuncture treatment. Outcome Measures • The study (1) evaluated neurological function using the modified neurological severity score; (2) examined the ultrastructure; (3) assessed the infarct volume; (4) determined levels of serum

  1. Wilms' tumor 1 (Wt1) regulates pleural mesothelial cell plasticity and transition into myofibroblasts in idiopathic pulmonary fibrosis

    PubMed Central

    Karki, Suman; Surolia, Ranu; Hock, Thomas David; Guroji, Purusotham; Zolak, Jason S.; Duggal, Ryan; Ye, Tong; Thannickal, Victor J.; Antony, Veena B.

    2014-01-01

    Pleural mesothelial cells (PMCs), which are derived from the mesoderm, exhibit an extraordinary capacity to undergo phenotypic changes during development and disease. PMC transformation and trafficking has a newly defined role in idiopathic pulmonary fibrosis (IPF); however, the contribution of Wilms' tumor 1 (Wt1)-positive PMCs to the generation of pathognomonic myofibroblasts remains unclear. PMCs were obtained from IPF lung explants and healthy donor lungs that were not used for transplantation. Short hairpin Wt1-knockdown PMCs (sh Wt1) were generated with Wt1 shRNA, and morphologic and functional assays were performed in vitro. Loss of Wt1 abrogated the PMC phenotype and showed evidence of mesothelial-to-mesenchymal transition (MMT), with a reduced expression of E-cadherin and an increase in the profibrotic markers α-smooth muscle actin (α-SMA) and fibronectin, along with increased migration and contractility, compared with that of the control. Migration of PMCs in response to active transforming growth factor (TGF)-β1 was assessed by live-cell imaging with 2-photon microscopy and 3D imaging, of Wt1-EGFP transgenic mice. Lineage-tracing experiments to map the fate of Wt1+ PMCs in mouse lung in response to TGF-β1 were also performed by using a Cre-loxP system. Our results, for the first time, demonstrate that Wt1 is necessary for the morphologic integrity of pleural membrane and that loss of Wt1 contributes to IPF via MMT of PMCs into a myofibroblast phenotype.—Karki, S., Surolia, R., Hock, T. D., Guroji, P., Zolak, J. S., Duggal, R., Ye, T., Thannickal, V., J., Antony, V. B. Wilms' tumor 1 (Wt1) regulates pleural mesothelial cell plasticity and transition into myofibroblasts in idiopathic pulmonary fibrosis. PMID:24265486

  2. Co-Transcriptomes of Initial Interactions In Vitro between Streptococcus Pneumoniae and Human Pleural Mesothelial Cells

    PubMed Central

    Heath, Claire J.; del Mar Cendra, Maria; Watson, Alastair; Auger, Jean-Philippe; Pandey, Anish; Tighe, Paddy; Christodoulides, Myron

    2015-01-01

    Streptococcus pneumoniae (Spn) is a major causative organism of empyema, an inflammatory condition occurring in the pleural sac. In this study, we used human and Spn cDNA microarrays to characterize the transcriptional responses occurring during initial contact between Spn and a human pleural mesothelial cell line (PMC) in vitro. Using stringent filtering criteria, 42 and 23 Spn genes were up-and down-regulated respectively. In particular, genes encoding factors potentially involved in metabolic processes and Spn adherence to eukaryotic cells were up-regulated e.g. glnQ, glnA, aliA, psaB, lytB and nox. After Spn initial contact, 870 human genes were differentially regulated and the largest numbers of significant gene expression changes were found in canonical pathways for eukaryotic initiation factor 2 signaling (60 genes out of 171), oxidative phosphorylation (32/103), mitochondrial dysfunction (37/164), eIF4 and p70S6K signaling (28/142), mTOR signaling (27/182), NRF2-mediated oxidative stress response (20/177), epithelial adherens junction remodeling (11/66) and ubiquitination (22/254). The cellular response appeared to be directed towards host cell survival and defense. Spn did not activate NF-kB or phosphorylate p38 MAPK or induce cytokine production from PMC. Moreover, Spn infection of TNF-α pre-stimulated PMC inhibited production of IL-6 and IL-8 secretion by >50% (p<0.01). In summary, this descriptive study provides datasets and a platform for examining further the molecular mechanisms underlying the pathogenesis of empyema. PMID:26566142

  3. Cytotoxicity and anaphase aberrations induced by mineral fibres in cultured human mesothelial cells.

    PubMed

    Pelin, K; Husgafvel-Pursiainen, K; Vallas, M; Vanhala, E; Linnainmaa, K

    1992-09-01

    The in vitro cytotoxicity of two amphibole asbestos fibres (amosite and crocidolite), a serpentine asbestos (chrysotile), a non-asbestos fibrous aluminosilicate (erionite) and three different size fractions of both glass wool and rock wool fibres were assessed in an immortalized human mesothelial cell line, MeT-5A. We also investigated the induction of anaphase aberrations by the asbestos and erionite fibres. On a comparison by weight, amosite, crocidolite and chrysotile showed similar toxic effects (2-5 mug/cm(2) of the asbestos fibres caused 50% of cells to die) but erionite was less toxic (10-20 mug/cm(2) was needed for the same effect). When the doses were converted to the number of fibres/cm(2) of culture area, amosite was shown to be about 10 times more cytotoxic than crocidolite and chrysotile. Crocidolite and chrysotile showed similar cytotoxicity, and erionite was again less toxic. Of the man-made mineral fibres (MMMF), thin glass wool was the most cytotoxic (50% cell death for 10-20 mug/cm(2)), followed (in descending order of cytotoxicity) by thin rock wool, coarse glass wool, milled rock wool, milled glass wool and coarse rock wool. In general, the MMMF samples were less toxic than the asbestos and erionite samples. All three asbestos types studied induced anaphase aberrations at high (near toxic) doses. A statistically significant increase in the number of aberrant anaphases was observed in cultures treated with crocidolite or chrysotile at 5 mug/cm(2). The increase was caused by lagging chromatids, chromosomes or chromosome fragments.

  4. Fibroblast-induced switching to the mesenchymal-like phenotype and PI3K/mTOR signaling protects melanoma cells from BRAF inhibitors

    PubMed Central

    Seip, Kotryna; Nygaard, Vigdis; Haugen, Mads H.; Engesæter, Birgit Ø.; Mælandsmo, Gunhild M.; Prasmickaite, Lina

    2016-01-01

    The knowledge on how tumor-associated stroma influences efficacy of anti-cancer therapy just started to emerge. Here we show that lung fibroblasts reduce melanoma sensitivity to the BRAF inhibitor (BRAFi) vemurafenib only if the two cell types are in close proximity. In the presence of fibroblasts, the adjacent melanoma cells acquire de-differentiated mesenchymal-like phenotype. Upon treatment with BRAFi, such melanoma cells maintain high levels of phospho ribosomal protein S6 (pS6), i.e. active mTOR signaling, which is suppressed in the BRAFi sensitive cells without stromal contacts. Inhibitors of PI3K/mTOR in combination with BRAFi eradicate pS6high cell subpopulations and potentiate anti-cancer effects in melanoma protected by the fibroblasts. mTOR and BRAF co-inhibition also delayed the development of early-stage lung metastases in vivo. In conclusion, we demonstrate that upon influence from fibroblasts, melanoma cells undergo a phenotype switch to the mesenchymal state, which can support PI3K/mTOR signaling. The lost sensitivity to BRAFi in such cells can be overcome by co-targeting PI3K/mTOR. This knowledge could be explored for designing BRAFi combination therapies aiming to eliminate both stroma-protected and non-protected counterparts of metastases. PMID:26918352

  5. The use of the NEDD8 inhibitor MLN4924 (Pevonedistat) in a cyclotherapy approach to protect wild-type p53 cells from MLN4924 induced toxicity.

    PubMed

    Malhab, Lara J Bou; Descamps, Simon; Delaval, Benedicte; Xirodimas, Dimitris P

    2016-11-30

    Targetting the ubiquitin pathway is an attractive strategy for cancer therapy. The inhibitor of the ubiquitin-like molecule NEDD8 pathway, MLN4924 (Pevonedistat) is in Phase II clinical trials. Protection of healthy cells from the induced toxicity of the treatment while preserving anticancer efficacy is a highly anticipated outcome in chemotherapy. Cyclotherapy was proposed as a promising approach to achieve this goal. We found that cytostatic activation of p53 protects cells against MLN4924-induced toxicity and importantly the effects are reversible. In contrast, cells with mutant or no p53 remain sensitive to NEDD8 inhibition. Using zebrafish embryos, we show that MLN4924-induced apoptosis is reduced upon pre-treatment with actinomycin D in vivo. Our studies show that the cellular effects of NEDD8 inhibition can be manipulated based on the p53 status and that NEDD8 inhibitors can be used in a p53-based cyclotherapy protocol to specifically target cancer cells devoid of wild type p53 function, while healthy cells will be protected from the induced toxicity.

  6. The use of the NEDD8 inhibitor MLN4924 (Pevonedistat) in a cyclotherapy approach to protect wild-type p53 cells from MLN4924 induced toxicity

    PubMed Central

    Malhab, Lara J. Bou; Descamps, Simon; Delaval, Benedicte; Xirodimas, Dimitris P.

    2016-01-01

    Targetting the ubiquitin pathway is an attractive strategy for cancer therapy. The inhibitor of the ubiquitin-like molecule NEDD8 pathway, MLN4924 (Pevonedistat) is in Phase II clinical trials. Protection of healthy cells from the induced toxicity of the treatment while preserving anticancer efficacy is a highly anticipated outcome in chemotherapy. Cyclotherapy was proposed as a promising approach to achieve this goal. We found that cytostatic activation of p53 protects cells against MLN4924-induced toxicity and importantly the effects are reversible. In contrast, cells with mutant or no p53 remain sensitive to NEDD8 inhibition. Using zebrafish embryos, we show that MLN4924-induced apoptosis is reduced upon pre-treatment with actinomycin D in vivo. Our studies show that the cellular effects of NEDD8 inhibition can be manipulated based on the p53 status and that NEDD8 inhibitors can be used in a p53-based cyclotherapy protocol to specifically target cancer cells devoid of wild type p53 function, while healthy cells will be protected from the induced toxicity. PMID:27901050

  7. Cross metathesis with hydroxamate and benzamide BOC-protected alkenes to access HDAC inhibitors and their biological evaluation highlighted intrinsic activity of BOC-protected dihydroxamates.

    PubMed

    Zwick, Vincent; Nurisso, Alessandra; Simões-Pires, Claudia; Bouchet, Samuel; Martinet, Nadine; Lehotzky, Attila; Ovadi, Judit; Cuendet, Muriel; Blanquart, Christophe; Bertrand, Philippe

    2016-01-01

    Conditions for the metathesis of alkenes in the convergent synthesis of HDAC inhibitors have been improved by continuous catalyst flow injection in the reaction media. Intermediate and target compounds obtained were tested for their ability to induce HDAC inhibition and tubulin acetylation, revealing the key role of the tert-butyloxycarbonyl (BOC) group for more HDAC6 selectivity. Molecular modelling added rationale for this BOC effect.

  8. Heme Oxygenase-1 Deficiency Diminishes Methicillin-Resistant Staphylococcus aureus Clearance Due to Reduced TLR9 Expression in Pleural Mesothelial Cells

    PubMed Central

    Gahlot, Satindra; Nasreen, Najmunnisa; Johnson, Judith A.; Sahn, Steven A.; Mohammed, Kamal A.

    2017-01-01

    Methicillin Resistant Staphylococcus aureus (MRSA) cause pneumonia and empyema thoraces. TLR9 activation provides protection against bacterial infections and Heme oxygenase-1 (HO-1) is known to enhance host innate immunity against bacterial infections. However, it is still unclear whether HO-1 regulates TLR-9 expression in the pleura and modulates the host innate defenses during MRSA empyema. In order to determine if HO-1 regulates host innate immune functions via modulating TLR expression, in MRSA empyema, HO-1+/+ and HO-1-/- mouse pleural mesothelial cells (PMCs) were infected with MRSA (1:10, MOI) in the presence or absence of Cobalt Protoporphyrin (CoPP) and Zinc Protoporphyrin (ZnPP) or CORM-2 (a Carbon monoxide donor) and the expression of mTLR9 and mBD14 was assessed by RT-PCR. In vivo, HO-1+/+ and HO-1-/- mice were inoculated with MRSA (5x106 CFU) intra-pleurally and host bacterial load was measured by CFU, and TLR9 expression in the pleura was determined by histochemical-immunostaining. We noticed MRSA inducing differential expression of TLR9 in HO-1+/+ and HO-1 -/- PMCs. In MRSA infected HO-1+/+ PMCs, TLR1, TLR4, and TLR9 expression was several fold higher than MRSA infected HO-1-/- PMCs. Particularly TLR9 expression was very low in MRSA infected HO-1-/- PMCs both in vivo and in vitro. Bacterial clearance was significantly higher in HO-1+/+ PMCs than compared to HO-1-/- PMCs in vitro, and blocking TLR9 activation diminished MRSA clearance significantly. In addition, HO-1-/- mice were unable to clear the MRSA bacterial load in vivo. MRSA induced TLR9 and mBD14 expression was significantly high in HO-1+/+ PMCs and it was dependent on HO-1 activity. Our findings suggest that HO-1 by modulating TLR9 expression in PMCs promotes pleural innate immunity in MRSA empyema. PMID:28052108

  9. Modulation of genotoxic effects in asbestos-exposed primary human mesothelial cells by radical scavengers, metal chelators and a glutathione precursor.

    PubMed

    Poser, Ina; Rahman, Qamar; Lohani, Mohtashim; Yadav, Santosh; Becker, Hans-Henner; Weiss, Dieter G; Schiffmann, Dietmar; Dopp, Elke

    2004-04-11

    The genotoxicity of asbestos fibers is generally mediated by reactive oxygen species (ROS) and by insufficient antioxidant protection. To further elucidate which radicals are involved in asbestos-mediated genotoxicity and to which extent, we have carried out experiments with the metal chelators deferoxamine (DEF) and phytic acid (PA), and with the radical scavengers superoxide dismutase (SOD), dimethylthiourea (DMTU) and the glutathione precursor Nacystelyn trade mark (NAL). We investigated the influence of these compounds on the potency of crocidolite, an amphibole asbestos fiber with a high iron content (27%), and chrysotile, a serpentine asbestos fiber with a low iron content (2%), to induce micronuclei (MN) in human mesothelial cells (HMC) after an exposure time of 24-72 h. Our results show that the number of crocidolite-induced MN is significantly reduced after pretreatment of fibers with PA and DEF. This effect was not observed with chrysotile. In contrast, simultaneous treatment of cells with asbestos and the OH*scavenging DMTU or the O2- -scavenging SOD significantly decreased the number of MN induced by chrysotile and crocidolite. In particular, DMTU almost completely suppressed micronucleus induction by both fiber types. A similar effect was observed in the presence of the H(2)O(2)-scavenging NAL after chrysotile treatment of HMC. By means of kinetochore analysis, it could be shown that the number of clastogenic events is decreased after PA and DEF pretreatment of fibers as well as after application of the above-mentioned scavengers. Our results show that chrysotile asbestos induces an increased release of H(2)O(2) in contrast to crocidolite. Also, the iron content of the fiber plays an important role in radical formation, but nevertheless, chrysotile produces oxy radicals to a similar extent as crocidolite, probably by phagocytosis-mediated oxidative bursting.

  10. Cross-Omics Comparison of Stress Responses in Mesothelial Cells Exposed to Heat- versus Filter-Sterilized Peritoneal Dialysis Fluids

    PubMed Central

    Kratochwill, Klaus; Bender, Thorsten O.; Lichtenauer, Anton M.; Herzog, Rebecca; Tarantino, Silvia; Bialas, Katarzyna; Jörres, Achim; Aufricht, Christoph

    2015-01-01

    Recent research suggests that cytoprotective responses, such as expression of heat-shock proteins, might be inadequately induced in mesothelial cells by heat-sterilized peritoneal dialysis (PD) fluids. This study compares transcriptome data and multiple protein expression profiles for providing new insight into regulatory mechanisms. Two-dimensional difference gel electrophoresis (2D-DIGE) based proteomics and topic defined gene expression microarray-based transcriptomics techniques were used to evaluate stress responses in human omental peritoneal mesothelial cells in response to heat- or filter-sterilized PD fluids. Data from selected heat-shock proteins were validated by 2D western-blot analysis. Comparison of proteomics and transcriptomics data discriminated differentially regulated protein abundance into groups depending on correlating or noncorrelating transcripts. Inadequate abundance of several heat-shock proteins following exposure to heat-sterilized PD fluids is not reflected on the mRNA level indicating interference beyond transcriptional regulation. For the first time, this study describes evidence for posttranscriptional inadequacy of heat-shock protein expression by heat-sterilized PD fluids as a novel cytotoxic property. Cross-omics technologies introduce a novel way of understanding PDF bioincompatibility and searching for new interventions to reestablish adequate cytoprotective responses. PMID:26495307

  11. Cross-omics comparison of stress responses in mesothelial cells exposed to heat- versus filter-sterilized peritoneal dialysis fluids.

    PubMed

    Kratochwill, Klaus; Bender, Thorsten O; Lichtenauer, Anton M; Herzog, Rebecca; Tarantino, Silvia; Bialas, Katarzyna; Jörres, Achim; Aufricht, Christoph

    2015-01-01

    Recent research suggests that cytoprotective responses, such as expression of heat-shock proteins, might be inadequately induced in mesothelial cells by heat-sterilized peritoneal dialysis (PD) fluids. This study compares transcriptome data and multiple protein expression profiles for providing new insight into regulatory mechanisms. Two-dimensional difference gel electrophoresis (2D-DIGE) based proteomics and topic defined gene expression microarray-based transcriptomics techniques were used to evaluate stress responses in human omental peritoneal mesothelial cells in response to heat- or filter-sterilized PD fluids. Data from selected heat-shock proteins were validated by 2D western-blot analysis. Comparison of proteomics and transcriptomics data discriminated differentially regulated protein abundance into groups depending on correlating or noncorrelating transcripts. Inadequate abundance of several heat-shock proteins following exposure to heat-sterilized PD fluids is not reflected on the mRNA level indicating interference beyond transcriptional regulation. For the first time, this study describes evidence for posttranscriptional inadequacy of heat-shock protein expression by heat-sterilized PD fluids as a novel cytotoxic property. Cross-omics technologies introduce a novel way of understanding PDF bioincompatibility and searching for new interventions to reestablish adequate cytoprotective responses.

  12. An inhibitor of the Keap1-Nrf2 protein-protein interaction protects NCM460 colonic cells and alleviates experimental colitis

    PubMed Central

    Lu, Meng-Chen; Ji, Jian-Ai; Jiang, Yong-Lin; Chen, Zhi-Yun; Yuan, Zhen-Wei; You, Qi-Dong; Jiang, Zheng-Yu

    2016-01-01

    Ulcerative colitis (UC) is a chronic relapsing-remitting form of inflammatory bowel disease (IBD) that increases the risk of colorectal cancer, the third most common malignancy in humans. Oxidative stress is a risk factor for the development of UC. The Keap1-Nrf2-ARE pathway is one of the most important defensive mechanisms against oxidative and/or electrophilic stresses. In this study, we identified CPUY192018 as a potent small-molecule inhibitor of the Keap1-Nrf2 PPI, investigated the cyto-protective effects of CPUY192018 on the NCM460 colonic cells and evaluated whether treatment with the inhibitor of the Keap1-Nrf2 PPI exerts protection on an established experimental model of UC induced by dextran sodium sulfate (DSS). Our study clearly demonstrated that CPUY192018 had a cytoprotective effect against DSS in both NCM460 cells and mouse colon via the activation of Nrf2 signaling. These results suggested that activation of Nrf2 by directly inhibiting the Keap1-Nrf2 PPI may be beneficial as a treatment for UC. PMID:27215610

  13. Demonstration of multifunctional DNBM corrosion inhibitors in protective coatings for Naval Air/Weapon Systems. Final report, September 1989-July 1992

    SciTech Connect

    Bailin, L.J.

    1993-12-01

    The corrosion protective properties of multifunctional DNBM salts (quaternary ammonium dichromate, nitrate, borate, and molybdate) have been demonstrated on high-strength steel and aluminum alloys found in prototype aerospace weapon systems. The 100% DNBM mixture added to MIL-P-23377 epoxy-polyamide, minus strontium chromate inhibitor, on bare 7075-T6 aluminum alloy resisted 1000 h ASTM B-117 salt spray. However, the coatings were not resistant to hydraulic fluid immersion at the higher concentrations required for the corrosion inhibition. Microencapsulation of the reactive DNBM mixture was adopted as a means to prevent this susceptibility, as well as the destructive oxidation of the hydroxyl groups in the epoxy resin during cure. In the scale-up operation, approximately 20 gallons of DNBM weighing 64 kg (141 lb) was prepared from the four starting quarternary salts synthesized in a chemical process pilot plant. The salts were mixed by dissolving in toluene. Following removal of solvent, the resultant dark-brown liquid, approximating molasses in viscosity, was microencapsulated by the following method: The DNBM was dispersed to form an oil-in-water emulsion in an aqueous colloidal solution of low-viscosity, high-purity methyl cellulose using a Gifford-Wood homogenizer, followed by spray drying in an Anhydro spray dryer. The maximum practicable payload was 75% DNBM. After spray drying, the capsules Corrosion inhibitors, DNBM, Microencapsulation, Epoxy primers, Protective coatings.

  14. Pioglitazone, a PPARγ agonist, provides comparable protection to angiotensin converting enzyme inhibitor ramipril against adriamycin nephropathy in rat.

    PubMed

    Ochodnicky, Peter; Mesarosova, Lucia; Cernecka, Hana; Klimas, Jan; Krenek, Peter; Goris, Maaike; van Dokkum, Richard P E; Henning, Robert H; Kyselovic, Jan

    2014-05-05

    Peroxisome proliferator-activated receptor γ (PPARγ) agonists have been shown to ameliorate diabetic nephropathy, but much less are known about their effects in non-diabetic nephropathies. In the present study, metabolic parameters, blood pressure, aortic endothelial function along with molecular and structural markers of glomerular and tubulointerstitial renal damage, were studied in a rat model of normotensive nephropathy induced by adriamycin and treated with PPARγ agonist pioglitazone (12mg/kg, po), angiotensin converting enzyme (ACE) inhibitor ramipril (1mg/kg, po) or their combination. Pioglitazone had no effect on systolic blood pressure, marginally reduced glycemia and improved aortic endothelium-dependent relaxation. In the kidney, pioglitazone prevented the development of proteinuria and focal glomerulosclerosis to the similar extent as blood-pressure lowering ramipril. Renoprotection provided by either treatment was associated with a reduction in the cortical expression of profibrotic plasminogen activator inhibitor-1 and microvascular damage-inducing endothelin-1, and a limitation of interstitial macrophage influx. Treatment with PPARγ agonist, as well as ACE inhibitor comparably affected renal expression of the renin-angiotensin system (RAS) components, normalizing increased renal expression of ACE and enhancing the expression of Mas receptor. Interestingly, combined pioglitazone and ramipril treatment did not provide any additional renoprotection. These results demonstrate that in a nondiabetic renal disease, such as adriamycin-induced nephropathy, PPARγ agonist pioglitazone provides renoprotection to a similar extent as an ACE inhibitor by interfering with the expression of local RAS components and attenuating related profibrotic and inflammatory mechanisms. The combination of the both agents, however, does not lead to any additional renal benefit.

  15. Protective effects of SGLT2 inhibitor luseogliflozin on pancreatic β-cells in obese type 2 diabetic db/db mice.

    PubMed

    Okauchi, Seizo; Shimoda, Masashi; Obata, Atsushi; Kimura, Tomohiko; Hirukawa, Hidenori; Kohara, Kenji; Mune, Tomoatsu; Kaku, Kohei; Kaneto, Hideaki

    2016-02-12

    It is well known that Sodium-Glucose Co-transporter 2 (SGLT2) inhibitors, new hypoglycemic agents, improve glycemic control by increasing urine glucose excretion, but it remained unclear how they exert protective effects on pancreatic β-cells. In this study, we examined the effects of SGLT2 inhibitor luseogliflozin on β-cell function and mass using obese type 2 diabetic db/db mice. Ten-week-old male diabetic db/db mice were treated with luseogliflozin 0.0025% or 0.01% in chow (Luse 0.0025% or Luse 0.01%) or vehicle (control) for 4 weeks. Urinary glucose excretion was increased in Luse groups (0.0025% and 0.01%) compared to control mice 3 days after the intervention. Fasting blood glucose levels were significantly lower in mice treated with Luse compared to control mice. Fasting serum insulin concentrations were significantly higher in mice treated with Luse compared to control mice. Triglyceride levels tended to be lower in Luse groups compared to control mice. In immunohistochemical study using pancreas tissues, β-cell mass was larger in Luse groups compared to control group which was due to the increase of β-cell proliferation and decrease of β-cell apoptosis. Furthermore, in gene analysis using isolated islets, insulin 1, insulin 2, MafA, PDX-1 and GLUT2 gene expression levels were significantly higher in Luse groups compared to control group. In contrast, expression levels of fibrosis-related gene such as TGFβ, fibronectin, collagen I and collagen III were significantly lower in Luse groups. In conclusion, SGLT2 inhibitor luseogliflozin ameliorates glycemic control and thus exerts protective effects on pancreatic β-cell mass and function.

  16. Effects of asbestos and man-made vitreous fibers on cell division in cultured human mesothelial cells in comparison to rodent cells.

    PubMed

    Pelin, K; Kivipensas, P; Linnainmaa, K

    1995-01-01

    We report the effects of chrysotile and crocidolite asbestos, and glass and rock wool fibers (man-made vitreous fibers, MMVF) on the induction of binucleate cells in vitro. The response of human mesothelial cells (target cells in fiber carcinogenesis) and rodent cells was compared. Human primary mesothelial cells, MeT-5A cells (an immortalized human mesothelial cell line), and rat liver epithelial (RLE) cells were exposed to asbestos and MMVF samples of similar size range. Milled glass wool, milled rock wool, and titanium dioxide were used as non-fibrous particle controls. All four fiber types caused statistically significant increases in the amount of binucleate cells in human primary mesothelial cells and MeT-5A cells (in the dose range 0.5-5.0 micrograms/cm2). Chrysotile and crocidolite asbestos were more effective (1.3-3.0-fold increases) than thin glass wool and thin rock wool fibers (1.3-2.2-fold increases). However, when the fiber doses were expressed as the number of fibers per culture area, the asbestos and MMVF appeared equally effective in human mesothelial cells. In RLE cells, chrysotile was the most potent inducer of binucleation (2.9-5.0-fold increases), but the response of the RLE cells to crocidolite, thin glass wool, and thin rock wool fibers was similar to the response of the human mesothelial cells. No statistically significant increases in the number of bi- or multinucleate cells were observed in human primary mesothelial cells or RLE cells exposed to the non-fibrous dusts. In MeT-5A cells exposed to 5 micrograms/cm2 of milled glass wool and milled rock wool, as well as in cultures exposed to 2 and 5 micrograms/cm2 of TiO2, significant increases were, however, observed. Our results show that rodent cells respond differently to mineral fibers than human cells. The results also add evidence to the suggested importance of disturbed cell division in fiber carcinogenesis.

  17. Fatty acid transport protein-2 inhibitor Grassofermata/CB5 protects cells against lipid accumulation and toxicity

    SciTech Connect

    Saini, Nipun; Black, Paul N.; Montefusco, David; DiRusso, Concetta C.

    2015-09-25

    The inhibition of the fatty acid uptake into non-adipose tissues provides an attractive target for prevention of lipotoxicity leading to obesity-associated non-alcoholic fatty liver disease and type 2 diabetes. Fatty acid transport proteins (FATPs) are bifunctional proteins involved in the uptake and activation of fatty acids by esterification with coenzyme A. Here we characterize Grassofermata/CB5, previously identified as a fatty acid uptake inhibitor directed against HsFATP2. The compound was effective in inhibiting the uptake of fatty acids in the low micro-molar range (IC{sub 50} 8–11 μM) and prevented palmitate-mediated lipid accumulation and cell death in cell lines that are models for intestines, liver, muscle and pancreas. In adipocytes, uptake inhibition was less effective (IC{sub 50} 58 μM). Inhibition was specific for long chain fatty acids and was ineffective toward medium chain fatty acids, which are transported by diffusion. Kinetic analysis of Grassofermata-dependent FA transport inhibition verified a non-competitive mechanism. By comparison with Grassofermata, several atypical antipsychotic drugs previously implicated as inhibitors of FA uptake were ineffectual. In mice Grassofermata decreased absorption of {sup 13}C-oleate demonstrating its potential as a therapeutic agent. - Highlights: • Grassofermata is a small compound inhibitor of FATP2. • Uptake inhibition is specific for long chain fatty acids. • Uptake kinetics shows low specificity for adipocytes compared to other cell types. • Inhibition is by a non-competitive mechanism. • Atypical antipsychotics do not inhibit FA uptake by comparison with Grassofermata.

  18. Fatty Acid Transport Protein-2 inhibitor Grassofermata/CB5 protects cells against lipid accumulation and toxicity

    PubMed Central

    Saini, Nipun; Black, Paul N.; Montefusco, David; DiRusso, Concetta C.

    2015-01-01

    The inhibition of the fatty acid uptake into non-adipose tissues provides an attractive target for prevention of lipotoxicity leading to obesity-associated non-alcoholic fatty liver disease and type 2 diabetes. Fatty acid transport proteins (FATPs) are bifunctional proteins involved in the uptake and activation of fatty acids by esterification with coenzyme A. Here we characterize Grassofermata/CB5, previously identified as a fatty acid uptake inhibitor directed against HsFATP2. The compound was effective in inhibiting the uptake of fatty acids in the low micro-molar range (IC50 8–11μM) and prevented palmitate-mediated lipid accumulation and cell death in cell lines that are models for intestines, liver, muscle and pancreas. In adipocytes, uptake inhibition was less effective (IC50 58μM). Inhibition was specific for long chain fatty acids and was ineffective toward medium chain fatty acids, which are transported by diffusion. Kinetic analysis of Grassofermata-dependent FA transport inhibition verified a non-competitive mechanism. By comparison with Grassofermata, several atypical antipsychotic drugs previously implicated as inhibitors of FA uptake were ineffectual. In mice Grassofermata decreased absorption of 13C-oleate demonstrating its potential as a therapeutic agent. PMID:26284975

  19. Cell-permeable intrinsic cellular inhibitors of apoptosis protect and rescue intestinal epithelial cells from radiation-induced cell death

    PubMed Central

    Matsuzaki-Horibuchi, Shiori; Yasuda, Takeshi; Sakaguchi, Nagako; Yamaguchi, Yoshihiro; Akashi, Makoto

    2015-01-01

    One of the important mechanisms for gastrointestinal (GI) injury following high-dose radiation exposure is apoptosis of epithelial cells. X-linked inhibitor of apoptosis (XIAP) and cellular IAP2 (cIAP2) are intrinsic cellular inhibitors of apoptosis. In order to study the effects of exogenously added IAPs on apoptosis in intestinal epithelial cells, we constructed bacterial expression plasmids containing genes of XIAP (full-length, BIR2 domain and BIR3-RING domain with and without mutations of auto-ubiquitylation sites) and cIAP2 proteins fused to a protein-transduction domain (PTD) derived from HIV-1 Tat protein (TAT) and purified these cell-permeable recombinant proteins. When the TAT-conjugated IAPs were added to rat intestinal epithelial cells IEC6, these proteins were effectively delivered into the cells and inhibited apoptosis, even when added after irradiation. Our results suggest that PTD-mediated delivery of IAPs may have clinical potential, not only for radioprotection but also for rescuing the GI system from radiation injuries. PMID:25359904

  20. Cell-permeable intrinsic cellular inhibitors of apoptosis protect and rescue intestinal epithelial cells from radiation-induced cell death.

    PubMed

    Matsuzaki-Horibuchi, Shiori; Yasuda, Takeshi; Sakaguchi, Nagako; Yamaguchi, Yoshihiro; Akashi, Makoto

    2015-01-01

    One of the important mechanisms for gastrointestinal (GI) injury following high-dose radiation exposure is apoptosis of epithelial cells. X-linked inhibitor of apoptosis (XIAP) and cellular IAP2 (cIAP2) are intrinsic cellular inhibitors of apoptosis. In order to study the effects of exogenously added IAPs on apoptosis in intestinal epithelial cells, we constructed bacterial expression plasmids containing genes of XIAP (full-length, BIR2 domain and BIR3-RING domain with and without mutations of auto-ubiquitylation sites) and cIAP2 proteins fused to a protein-transduction domain (PTD) derived from HIV-1 Tat protein (TAT) and purified these cell-permeable recombinant proteins. When the TAT-conjugated IAPs were added to rat intestinal epithelial cells IEC6, these proteins were effectively delivered into the cells and inhibited apoptosis, even when added after irradiation. Our results suggest that PTD-mediated delivery of IAPs may have clinical potential, not only for radioprotection but also for rescuing the GI system from radiation injuries.

  1. A cell protection screen reveals potent inhibitors of multiple stages of the hepatitis C virus life cycle

    PubMed Central

    Chockalingam, Karuppiah; Simeon, Rudo L.; Rice, Charles M.; Chen, Zhilei

    2010-01-01

    The hepatitis C virus (HCV) life cycle involves multiple steps, but most current drug candidates target only viral replication. The inability to systematically discover inhibitors targeting multiple steps of the HCV life cycle has hampered antiviral development. We present a simple screen for HCV antivirals based on the alleviation of HCV-mediated cytopathic effect in an engineered cell line—n4mBid. This approach obviates the need for a secondary screen to avoid cytotoxic false-positive hits. Application of our screen to 1280 compounds, many in clinical trials or approved for therapeutic use, yielded >200 hits. Of the 55 leading hits, 47 inhibited one or more aspects of the HCV life cycle by >40%. Six compounds blocked HCV entry to levels similar to an antibody (JS-81) targeting the HCV entry receptor CD81. Seven hits inhibited HCV replication and/or infectious virus production by >100-fold, with one (quinidine) inhibiting infectious virus production by 450-fold relative to HCV replication levels. This approach is simple and inexpensive and should enable the rapid discovery of new classes of HCV life cycle inhibitors. PMID:20142494

  2. Inhibition of TGF-beta signaling by an ALK5 inhibitor protects rats from dimethylnitrosamine-induced liver fibrosis.

    PubMed

    de Gouville, Anne-Charlotte; Boullay, Valerie; Krysa, Gael; Pilot, Julia; Brusq, Jean-Marie; Loriolle, Florence; Gauthier, Jean-Michel; Papworth, Stephen A; Laroze, Alain; Gellibert, Françoise; Huet, Stephane

    2005-05-01

    1 Chronic liver disease is characterized by an exacerbated accumulation of matrix, causing progressive fibrosis, which may lead to cirrhosis. Transforming growth factor beta (TGF-beta), a well-known profibrotic cytokine, transduces its signal through the ALK5 ser/thr kinase receptor, and increases transcription of different genes including PAI-1 and collagens. The identification of GW6604 (2-phenyl-4-(3-pyridin-2-yl-1H-pyrazol-4-yl)pyridine), an ALK5 inhibitor, allowed us to evaluate the therapeutic potential of inhibiting TGF-beta pathway in different models of liver disease. 2 A cellular assay was used to identify GW6604 as a TGF-beta signaling pathway inhibitor. This ALK5 inhibitor was then tested in a model of liver hepatectomy in TGF-beta-overexpressing transgenic mice, in an acute model of liver disease and in a chronic model of dimethylnitrosamine (DMN)-induced liver fibrosis. 3 In vitro, GW6604 inhibited autophosphorylation of ALK5 with an IC(50) of 140 nM and in a cellular assay inhibited TGF-beta-induced transcription of PAI-1 (IC(50): 500 nM). In vivo, GW6604 (40 mg kg(-1) p.o.) increased liver regeneration in TGF-beta-overexpressing mice, which had undergone partial hepatectomy. In an acute model of liver disease, GW6604 reduced by 80% the expression of collagen IA1. In a chronic model of DMN-induced fibrosis where DMN was administered for 6 weeks and GW6604 dosed for the last 3 weeks (80 mg kg(-1) p.o., b.i.d.), mortality was prevented and DMN-induced elevations of mRNA encoding for collagen IA1, IA2, III, TIMP-1 and TGF-beta were reduced by 50-75%. Inhibition of matrix genes overexpression was accompanied by reduced matrix deposition and reduction in liver function deterioration, as assessed by bilirubin and liver enzyme levels. 4 Our results suggest that inhibition of ALK5 could be an attractive new approach to treatment of liver fibrotic diseases by both preventing matrix deposition and promoting hepatocyte regeneration.

  3. Metabolic and hemodynamic effects of sodium-dependent glucose co-transporter 2 inhibitors on cardio-renal protection in the treatment of patients with type 2 diabetes mellitus.

    PubMed

    Kashiwagi, Atsunori; Maegawa, Hiroshi

    2017-02-08

    The specific Na+/glucose co-transporter 2 inhibitors (SGLT2 inhibitors) inhibit glucose reabsorption in proximal renal tubular cells, and both fasting and postprandial glucose significantly decrease due to urinary glucose loss. As a result, pancreatic β-cell function and peripheral insulin action significantly improve with relief from glucose toxicity. Furthermore, whole body energy metabolism changes to relative glucose deficiency and triggers increased lipolysis in fat cells, and fatty acid oxidation and then ketone body production in the liver during treatment with SGLT2 inhibitors. In addition, SGLT2 inhibitors have profound hemodynamic effects including diuresis, dehydration, weight loss, and lowering blood pressure. The most recent findings on SGLT2 inhibitors come from results of the Empagliflozin, cardiovascular outcomes and mortality in type 2 diabetes trial. SGLT2 inhibitors exert extremely unique and cardio-renal protection through metabolic and hemodynamic effects with long-term durability on the reduction of blood glucose, body weight, and blood pressure. Although a site of action of SGLT2 inhibitors is highly specific to inhibit renal glucose reabsorption, whole body energy metabolism and hemodynamic and renal functions are profoundly modulated during the treatment of SGLT2 inhibitors. Previous studies suggest multifactorial clinical benefits and safety concerns of SGLT2 inhibitors. Although ambivalent clinical results of this drug are still under active discussion, the present review summarizes promising recent evidences on the cardio-renal and metabolic benefits of SGLT2 inhibitors in the treatment of type 2 diabetes. This article is protected by copyright. All rights reserved.

  4. Amadori adducts activate nuclear factor-κB-related proinflammatory genes in cultured human peritoneal mesothelial cells

    PubMed Central

    Nevado, Julián; Peiró, Concepción; Vallejo, Susana; El-Assar, Mariam; Lafuente, Nuria; Matesanz, Nuria; Azcutia, Veronica; Cercas, Elena; Sánchez-Ferrer, Carlos F; Rodríguez-Mañas, Leocadio

    2005-01-01

    Diabetes mellitus leads to a high incidence of several so-called complications, sharing similar pathophysiological features in several territories. Previous reports points at early nonenzymatic glycosylation products (Amadori adducts) as mediators of diabetic vascular complications. In the present study, we analysed a possible role for Amadori adducts as stimulators of proinflammatory pathways in human peritoneal mesothelial cells (HPMCs). Cultured HPMCs isolated from 13 different patients (mean age 38.7±16 years) were exposed to different Amadori adducts, that is, highly glycated haemoglobin (10 nM) and glycated bovine serum albumin (0.25 mg ml−1), as well as to their respective low glycosylation controls. Amadori adducts, but not their respective controls, elicited a marked increase of NF-κB activation, as determined by electromobility shift assays and transient transfection experiments. Additionally, Amadori adducts significantly increased the production of NF-κB-related proinflammatory molecules, including cytokines, such as TNF-α, IL-1β or IL-6, and enzymes, such as cyclooxygenase-2 and inducible nitric oxide (NO) synthase, this latter leading to the release of NO by HPMCs. The effects of Amadori adducts were mediated by different reactive oxygen and nitrosative species (e.g. superoxide anions, hydroxyl radicals, and peroxynitrite), as they were blunted by coincubation with the appropriate scavengers. Furthermore, NO generated upon exposure to Amadori adducts further stimulated NF-κB activation, either directly or after combination with superoxide anions to form peroxynitrite. We conclude that Amadori adducts can favour peritoneal inflammation by exacerbating changes in NO synthesis pathway and triggering NF-κB-related proinflammatory signals in human mesothelial cells. PMID:15997235

  5. TLR2 contributes to trigger immune response of pleural mesothelial cells against Mycobacterium bovis BCG and M. tuberculosis infection.

    PubMed

    Hwanga, Eun-Ha; Kim, Tae-Hyoun; Park, Ji-Yeon; Hong, Jung Joo; Kim, Dong-Hyun; Ha, Sang-Jun; Yang, Soo-Jin; Shin, Sung Jae; Park, Jong-Hwan

    2017-02-25

    Mycobacterium tuberculosis is a causative agent leading to pleural effusion, characterized by the accumulation of fluid and immune cells in the pleural cavity. Although this phenomenon has been described before, detailed processes or mechanisms associated with the pleural effusion are still not well understood. Pleural mesothelial cells (PMCs) are specialized epithelial cells that cover the body wall and internal organs in pleural cavity playing a central role in pleural inflammation. Toll-like receptors are expressed in various cell types including mesothelial cells and initiate the recognition and defense against mycobacterial infection. In the present study, we investigated direct immune responses of PMCs against two mycobacterial strains, M. bovis vaccine strain Bacille Calmette-Guérin (BCG) and M. tuberculosis virulent strain H37Rv, and the role of TLR2 in such responses. Infection with BCG and H37Rv increased the production of IL-6, CXCL1, and CCL2 in WT PMCs, which was partially impaired in TLR2-deficient cells. In addition, the activation of NF-κB and MAPKs induced by BCG and H37Rv was suppressed in TLR2-deficient PMCs, as compared with the WT cells. TLR2 deficiency led to the decrease of nitric oxide (NO) production through the delayed gene expression of iNOS in PMCs. TLR2 was also shown to be essential for optimal expression of cellular adhesion molecules such as ICAM-1 and VCAM-1 in PMCs in response to BCG and H37Rv. These findings strongly suggest that TLR2 participates in mycobacteria-induced innate immune responses in PMCs and may play a role in pathogenesis of tuberculosis pleural effusion.

  6. Inactivation of the Cullin (CUL)-RING E3 ligase by the NEDD8-activating enzyme inhibitor MLN4924 triggers protective autophagy in cancer cells.

    PubMed

    Luo, Zhongguang; Pan, Yongfu; Jeong, Lak Shin; Liu, Jie; Jia, Lijun

    2012-11-01

    The multiunit Cullin (CUL)-RING E3 ligase (CRL) controls diverse biological processes by targeting a mass of substrates for ubiquitination and degradation, whereas its dysfunction causes carcinogenesis. Post-translational neddylation of CUL, a process triggered by the NEDD8-activating enzyme E1 subunit 1 (NAE1), is required for CRL activation. Recently, MLN4924 was discovered via a high-throughput screen as a specific NAE1 inhibitor and first-in-class anticancer drug. By blocking CUL neddylation, MLN4924 inactivates CRL and causes the accumulation of CRL substrates that trigger cell cycle arrest, senescence and/or apoptosis to suppress the growth of cancer cells in vitro and in vivo. Recently, we found that MLN4924 also triggers protective autophagy in response to CRL inactivation. MLN4924-induced autophagy is attributed partially to the inhibition of mechanistic target of rapamycin (also known as mammalian target of rapamycin, MTOR) activity by the accumulation of the MTOR inhibitory protein DEPTOR, as well as reactive oxygen species (ROS)-induced stress. Moreover, the blockage of autophagy response enhances apoptosis in MLN4924-treated cells. Together, our findings not only reveal autophagy as a novel cellular response to CRL inactivation by MLN4924, but also provide a piece of proof-of-concept evidence for the combination of MLN4924 with autophagy inhibitors to enhance therapeutic efficacy.

  7. The 11β-hydroxysteroid dehydrogenase type 1 inhibitor protects against the insulin resistance and hepatic steatosis in db/db mice.

    PubMed

    Yuan, Xiaohuan; Li, Hongzhi; Bai, He; Zhao, Xiaojin; Zhang, Chunlei; Liu, Haifeng; Zhang, Yufei; Zhao, Binghai; Wu, Yan; Liu, Jieting; Xiang, Qi; Feng, Biao; Chu, Yanhui; Huang, Yadong

    2016-10-05

    Glucocorticoids (GCs) metabolism is regulated by 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1). When GCs are present in excess, they can impair glucose-dependent insulin sensitivity. We have previously synthesized several curcumin analogues, of which four compounds were selective inhibitors of 11β-HSD1. Here, we present data supporting that the 11β-hydroxysteroid dehydrogenase type 1 inhibitor (H8) inhibits insulin resistance and ameliorates hepatic steatosis in db/db mice. We compared glucose and lipid metabolism in db/db mice with or without administration of H8, which significantly decreased fasting blood glucose levels and protected against insulin resistance and hepatic steatosis compared to when glucose and lipid metabolism were measured following curcumin administration. The hepatic enzyme was reduced significantly in the plasma samples from db/db mice which were treated with H8. Serum corticosterone (active) levels, which are regulated by 11β-HSD1 were reduced when mice received H8. H8 administration suppressed phosphoenolpyruvate carboxykinase (PEPCK) and glucose-6-phosphatase (G6-pase) expression, which are related to gluconeogenesis and enhanced glucose transporter 4 (GLUT4) protein content in liver. Treatment with H8 improved obesity and metabolic disorders, such as insulin resistance and hepatic steatosis by suppressing activity of 11β-HSD1, suggesting that H8 might be a beneficial drug for the treatment of obesity and Type-2 diabetes (T2D).

  8. The MEK-Inhibitor Selumetinib Attenuates Tumor Growth and Reduces IL-6 Expression but Does Not Protect against Muscle Wasting in Lewis Lung Cancer Cachexia.

    PubMed

    Au, Ernie D; Desai, Aditya P; Koniaris, Leonidas G; Zimmers, Teresa A

    2016-01-01

    Cachexia, or wasting of skeletal muscle and fat, afflicts many patients with chronic diseases including cancer, organ failure, and AIDS. Muscle wasting reduces quality of life and decreases response to therapy. Cachexia is caused partly by elevated inflammatory cytokines, including interleukin-6 (IL-6). Others and we have shown that IL-6 alone is sufficient to induce cachexia both in vitro and in vivo. The mitogen-activated protein/extracellular signal-regulated kinase kinase (MEK) inhibitor Selumetinib has been tested in clinical trials for various cancers. Moreover, Selumetinib has also been shown to inhibit the production of IL-6. In a retrospective analysis of a phase II clinical trial in advanced cholangiocarcinoma, patients treated with Selumetinib experienced significant gains in skeletal muscle vs. patients receiving standard therapy. However, the use of Selumetinib as a treatment for cachexia has yet to be investigated mechanistically. We sought to determine whether MEK inhibition could protect against cancer-induced cachexia in mice. In vitro, Selumetinib induced C2C12 myotube hypertrophy and nuclear accretion. Next we tested Selumetinib in the Lewis lung carcinoma (LLC) model of cancer cachexia. Treatment with Selumetinib reduced tumor mass and reduced circulating and tumor IL-6; however MEK inhibition did not preserve muscle mass. Similar wasting was seen in limb muscles of Selumetinib and vehicle-treated LLC mice, while greater fat and carcass weight loss was observed with Selumetinib treatment. As well, Selumetinib did not block wasting in C2C12 myotubes treated with LLC serum. Taken together, out results suggest that this MEK inhibitor is not protective in LLC cancer cachexia despite lowering IL-6 levels, and further that it might exacerbate tumor-induced weight loss. Differences from other studies might be disease, species or model-specific.

  9. The MEK-Inhibitor Selumetinib Attenuates Tumor Growth and Reduces IL-6 Expression but Does Not Protect against Muscle Wasting in Lewis Lung Cancer Cachexia

    PubMed Central

    Au, Ernie D.; Desai, Aditya P.; Koniaris, Leonidas G.; Zimmers, Teresa A.

    2017-01-01

    Cachexia, or wasting of skeletal muscle and fat, afflicts many patients with chronic diseases including cancer, organ failure, and AIDS. Muscle wasting reduces quality of life and decreases response to therapy. Cachexia is caused partly by elevated inflammatory cytokines, including interleukin-6 (IL-6). Others and we have shown that IL-6 alone is sufficient to induce cachexia both in vitro and in vivo. The mitogen-activated protein/extracellular signal-regulated kinase kinase (MEK) inhibitor Selumetinib has been tested in clinical trials for various cancers. Moreover, Selumetinib has also been shown to inhibit the production of IL-6. In a retrospective analysis of a phase II clinical trial in advanced cholangiocarcinoma, patients treated with Selumetinib experienced significant gains in skeletal muscle vs. patients receiving standard therapy. However, the use of Selumetinib as a treatment for cachexia has yet to be investigated mechanistically. We sought to determine whether MEK inhibition could protect against cancer-induced cachexia in mice. In vitro, Selumetinib induced C2C12 myotube hypertrophy and nuclear accretion. Next we tested Selumetinib in the Lewis lung carcinoma (LLC) model of cancer cachexia. Treatment with Selumetinib reduced tumor mass and reduced circulating and tumor IL-6; however MEK inhibition did not preserve muscle mass. Similar wasting was seen in limb muscles of Selumetinib and vehicle-treated LLC mice, while greater fat and carcass weight loss was observed with Selumetinib treatment. As well, Selumetinib did not block wasting in C2C12 myotubes treated with LLC serum. Taken together, out results suggest that this MEK inhibitor is not protective in LLC cancer cachexia despite lowering IL-6 levels, and further that it might exacerbate tumor-induced weight loss. Differences from other studies might be disease, species or model-specific. PMID:28149280

  10. Protective effects of SKF-96365, a non-specific inhibitor of SOCE, against MPP+-induced cytotoxicity in PC12 cells: potential role of Homer1.

    PubMed

    Chen, Tao; Zhu, Jie; Zhang, Chi; Huo, Kai; Fei, Zhou; Jiang, Xiao-fan

    2013-01-01

    Parkinson's disease (PD) is the most common neurodegenerative movement disorder, characterized by loss of dopominergic (DA) neurons in substantia nigra pars compacta (SNpc), and can be experimentally mimicked by the neurotoxin MPP(+) in vitro models. In this study, we investigated the potential protective effect of SKF-96365, a non-specific inhibitor of SOCE (store-operated calcium entry), on MPP(+) induced cytotoxicity in PC12 cells. We found that pretreatment with SKF-96365 (10 µM and 50 µM) 30 min before injury significantly increased cell viability, decreased LDH release, prevented nuclear damage, and inhibited apoptotic cell death in MPP(+) stressed PC12 cells. The results of calcium image using the ratiometric calcium indicator Fura-2-AM also showed that SKF-96365 reduced the intracellular calcium overload induced by MPP(+) in PC12 cells. In addition, SKF-96365 decreased the expression of Homer1, a more recently discovered postsynaptic scaffolding protein with calcium modulating function, following MPP(+) administration in PC12 cells, while had no statistically significant effects on endoplasmic reticulum (ER) calcium concentration. Furthermore, overexpression of Homer1 by using recombinant lentivirus partly reversed protective effects of SKF-96365 against MPP(+) injury. The ER Ca(2+) release was further amplified and ER calcium recovery was delayed by Homer1 upregulation in PC12 cells following MPP(+) insult. Taken together, these data suggest that SKF-96365 protects PC12 cells against MPP(+) induced cytotoxicity, and this protection may be at least in part on the inhibition of intracellular calcium overload and suppression of Homer1-mediated ER Ca(2+) release.

  11. Blood-Brain Barrier Disruption and Neurovascular Unit Dysfunction in Diabetic Mice: Protection with the Mitochondrial Carbonic Anhydrase Inhibitor Topiramate.

    PubMed

    Salameh, Therese S; Shah, Gul N; Price, Tulin O; Hayden, Melvin R; Banks, William A

    2016-12-01

    All forms of diabetes mellitus are characterized by chronic hyperglycemia, resulting in the development of a number of microvascular and macrovascular pathologies. Diabetes is also associated with changes in brain microvasculature, leading to dysfunction and ultimately disruption of the blood-brain barrier (BBB). These changes are correlated with a decline in cognitive function. In diabetes, BBB damage is associated with increased oxidative stress and reactive oxygen species. This occurs because of the increased oxidative metabolism of glucose caused by hyperglycemia. Decreasing the production of bicarbonate with the use of a mitochondrial carbonic anhydrase inhibitor (mCAi) limits oxidative metabolism and the production of reactive oxygen species. In this study, we have demonstrated that 1) streptozotocin-induced diabetes resulted in BBB disruption, 2) ultrastructural studies showed a breakdown of the BBB and changes to the neurovascular unit (NVU), including a loss of brain pericytes and retraction of astrocytes, the two cell types that maintain the BBB, and 3) treatment with topiramate, a mCAi, attenuated the effects of diabetes on BBB disruption and ultrastructural changes in the neurovascular unit.

  12. Selective Nitric Oxide Synthase Inhibitor 7-Nitroindazole Protects against Cocaine-Induced Oxidative Stress in Rat Brain

    PubMed Central

    Vitcheva, Vessela; Simeonova, Rumyana; Kondeva-Burdina, Magdalena; Mitcheva, Mitka

    2015-01-01

    One of the mechanisms involved in the development of addiction, as well as in brain toxicity, is the oxidative stress. The aim of the current study was to investigate the effects of 7-nitroindazole (7-NI), a selective inhibitor of neuronal nitric oxide synthase (nNOS), on cocaine withdrawal and neurotoxicity in male Wistar rats. The animals were divided into four groups: control; group treated with cocaine (15 mg/kg−1, i.p., 7 days); group treated with 7-NI (25 mg/kg−1, i.p., 7 days); and a combination group (7-NI + cocaine). Cocaine repeated treatment resulted in development of physical dependence, judged by withdrawal symptoms (decreased locomotion, increased salivation and breathing rate), accompanied by an increased nNOS activity and oxidative stress. The latter was discerned by an increased formation of malondialdehyde (MDA), depletion of reduced glutathione (GSH) levels, and impairment of the enzymatic antioxidant defense system measured in whole brain. In synaptosomes, isolated from cocaine-treated rats, mitochondrial activity and GSH levels were also decreased. 7-NI administered along with cocaine not only attenuated the withdrawal, due to its nNOS inhibition, but also reversed both the GSH levels and antioxidant enzyme activities near control levels. PMID:26576217

  13. A DNA synthesis inhibitor is protective against proteotoxic stressors via modulation of fertility pathways in Caenorhabditis elegans

    PubMed Central

    Angeli, Suzanne; Klang, Ida; Sivapatham, Renuka; Mark, Karla; Zucker, David; Bhaumik, Dipa; Lithgow, Gordon J.; Andersen, Julie K.

    2013-01-01

    Loss of germline precursor cells in C. elegans has previously been shown to improve protein homeostasis and extend lifespan, possibly due to reallocation of resources to somatic cells. In contrast, mutants that are sterile simply due to loss of sperm or oocyte production have a normal lifespan, often leading to the conclusion that loss of reproduction per se may have minor effects on C. elegans. We have found that inhibiting reproduction in C. elegans via the DNA synthesis inhibitor 5-fluoro-2-deoxyuridine (FUdR) improves protein homeostasis, stress resistance, and healthspan in wild-type animals. We find that FUdR is dependent on oogenesis and oocytic maturation. The effects of FUdR are dependent on FEM pathways, which regulate initiation of spermatogenesis. Loss of FEM expression leads to feminized animals that maintain arrested oocytes and are refractory to the effects of FUdR. FUdR-dependence is restored by spermatogenic signals, which trigger oocytic maturation and ovulation. Further, loss of FEM-3, a novel protein required for spermatogenesis, is sufficient to improve aspects of proteostasis. These effects are independent of previously described germline signals, including the DAF-16/FOXO, DAF-12/VDR, and HSF-1 pathways. These findings suggest that genetic or chemical inhibition of oocyte production can improve protein homeostasis in C. elegans. PMID:24123581

  14. Inhibitors of retrograde trafficking active against ricin and Shiga toxins also protect cells from several viruses, Leishmania and Chlamydiales.

    PubMed

    Gupta, Neetu; Noël, Romain; Goudet, Amélie; Hinsinger, Karen; Michau, Aurélien; Pons, Valérie; Abdelkafi, Hajer; Secher, Thomas; Shima, Ayaka; Shtanko, Olena; Sakurai, Yasuteru; Cojean, Sandrine; Pomel, Sébastien; Liévin-Le Moal, Vanessa; Leignel, Véronique; Herweg, Jo-Ana; Fischer, Annette; Johannes, Ludger; Harrison, Kate; Beard, Philippa M; Clayette, Pascal; Le Grand, Roger; Rayner, Jonathan O; Rudel, Thomas; Vacus, Joël; Loiseau, Philippe M; Davey, Robert A; Oswald, Eric; Cintrat, Jean-Christophe; Barbier, Julien; Gillet, Daniel

    2017-04-01

    Medical countermeasures to treat biothreat agent infections require broad-spectrum therapeutics that do not induce agent resistance. A cell-based high-throughput screen (HTS) against ricin toxin combined with hit optimization allowed selection of a family of compounds that meet these requirements. The hit compound Retro-2 and its derivatives have been demonstrated to be safe in vivo in mice even at high doses. Moreover, Retro-2 is an inhibitor of retrograde transport that affects syntaxin-5-dependent toxins and pathogens. As a consequence, it has a broad-spectrum activity that has been demonstrated both in vitro and in vivo against ricin, Shiga toxin-producing O104:H4 entero-hemorrhagic E. coli and Leishmania sp. and in vitro against Ebola, Marburg and poxviruses and Chlamydiales. An effect is anticipated on other toxins or pathogens that use retrograde trafficking and syntaxin-5. Since Retro-2 targets cell components of the host and not directly the pathogen, no selection of resistant pathogens is expected. These lead compounds need now to be developed as drugs for human use.

  15. The gap junction inhibitor 2-aminoethoxy-diphenyl-borate protects against acetaminophen hepatotoxicity by inhibiting cytochrome P450 enzymes and c-jun N-terminal kinase activation

    SciTech Connect

    Du, Kuo; Williams, C. David; McGill, Mitchell R.; Xie, Yuchao; Farhood, Anwar; Vinken, Mathieu; Jaeschke, Hartmut

    2013-12-15

    Acetaminophen (APAP) hepatotoxicity is the leading cause of acute liver failure in the US. Although many aspects of the mechanism are known, recent publications suggest that gap junctions composed of connexin32 function as critical intercellular communication channels which transfer cytotoxic mediators into neighboring hepatocytes and aggravate liver injury. However, these studies did not consider off-target effects of reagents used in these experiments, especially the gap junction inhibitor 2-aminoethoxy-diphenyl-borate (2-APB). In order to assess the mechanisms of protection of 2-APB in vivo, male C56Bl/6 mice were treated with 400 mg/kg APAP to cause extensive liver injury. This injury was prevented when animals were co-treated with 20 mg/kg 2-APB and was attenuated when 2-APB was administered 1.5 h after APAP. However, the protection was completely lost when 2-APB was given 4–6 h after APAP. Measurement of protein adducts and c-jun-N-terminal kinase (JNK) activation indicated that 2-APB reduced both protein binding and JNK activation, which correlated with hepatoprotection. Although some of the protection was due to the solvent dimethyl sulfoxide (DMSO), in vitro experiments clearly demonstrated that 2-APB directly inhibits cytochrome P450 activities. In addition, JNK activation induced by phorone and tert-butylhydroperoxide in vivo was inhibited by 2-APB. The effects against APAP toxicity in vivo were reproduced in primary cultured hepatocytes without use of DMSO and in the absence of functional gap junctions. We conclude that the protective effect of 2-APB was caused by inhibition of metabolic activation of APAP and inhibition of the JNK signaling pathway and not by blocking connexin32-based gap junctions. - Highlights: • 2-APB protected against APAP-induced liver injury in mice in vivo and in vitro • 2-APB protected by inhibiting APAP metabolic activation and JNK signaling pathway • DMSO inhibited APAP metabolic activation as the solvent of 2-APB

  16. JANEX-1, a JAK3 inhibitor, protects pancreatic islets from cytokine toxicity through downregulation of NF-{kappa}B activation and the JAK/STAT pathway

    SciTech Connect

    Lv, Na; Kim, Eun-Kyung; Song, Mi-Young; Choi, Ha-Na; Moon, Woo Sung; Park, Sung-Joo; Park, Jin-Woo; Kwon, Kang-Beom; Park, Byung-Hyun

    2009-07-15

    JANEX-1/WHI-P131, a selective Janus kinase 3 (JAK3) inhibitor, has been shown to delay the onset of diabetes in the NOD mouse model. However, the molecular mechanism by which JANEX-1 protects pancreatic {beta}-cells is unknown. In the current study, we investigated the role of JANEX-1 on interleukin (IL)-1{beta} and interferon (IFN)-{gamma}-induced {beta}-cell damage using isolated islets. JANEX-1-pretreated islets showed resistance to cytokine toxicity, namely suppressed nitric oxide (NO) production, reduced inducible form of NO synthase (iNOS) expression, and decreased islet destruction. The molecular mechanism by which JANEX-1 inhibits iNOS expression was mediated through suppression of the nuclear factor {kappa}B (NF-{kappa}B) and JAK/signal transducer and activator of transcription (STAT) pathways. Islets treated with the cytokines downregulated the protein levels of suppressor of cytokine signaling (SOCS)-1 and SOCS-3, but pretreatment with JANEX-1 attenuated these decreases. Additionally, islets from JAK3{sup -/-} mice were more resistant to cytokine toxicity than islets from control mice. These results demonstrate that JANEX-1 protects {beta}-cells from cytokine toxicity through suppression of the NF-{kappa}B and JAK/STAT pathways and upregulation of SOCS proteins, suggesting that JANEX-1 may be used to preserve functional {beta}-cell mass.

  17. 5-aminocoumarans: dual inhibitors of lipid peroxidation and dopamine release with protective effects against central nervous system trauma and ischemia.

    PubMed

    Ohkawa, S; Fukatsu, K; Miki, S; Hashimoto, T; Sakamoto, J; Doi, T; Nagai, Y; Aono, T

    1997-02-14

    A series of 2,3-dihydro-5-benzofuranamines (5-aminocoumarans) were developed for the treatment of traumatic and ischemic central nervous system (CNS) injury. Compounds within this class were extremely effective inhibitors of lipid peroxidation in vitro and antagonized excitatory behavior coupled with peroxidative injury induced by spinal intrathecal injection of FeCl2 (mouse-FeCl2-it assay) in vivo. Selected compounds were tested for antagonistic activity on methamphetamine (MAP)-induced hypermotility resulting from dopamine release in the mouse brain. Among the compounds synthesized, compound 26n (2,3-dihydro-2,4,6,7-tetramethyl-2-[(4-phenyl-1-piperidinyl) methyl]-5-benzofuranamine) exhibited potent effects in these assays (inhibition of lipid peroxidation, IC50 = 0.07 microM; mouse-FeCl2-it assay, ID50 = 10.4 mg/ kg, po; MAP-induced hypermotility, 98% inhibition, 10 mg/kg, ip). The S-(+)-form of compound 26n dihydrochloride (TAK-218), which has 30 times more potent antagonistic activity on MAP-induced hypermotility than the R-(-)-form, improved more significantly the survival rate in the cerebral ischemia model (rat, 1-3 mg/kg, ip) during the period of 1-14 days after ischemia and decreased functional disorders in the traumatic brain injury model (rat, 0.1-1 mg/kg, ip) 3-14 days after injury. These results imply a role for dopamine in deterioration of CNS function after ischemic and traumatic injury. TAK-218 is a promising compound for the treatment of stroke and CNS trauma and is now under clinical investigation.

  18. The protective effect of Rho-associated kinase inhibitor on aluminum-induced neurotoxicity in rat cortical neurons.

    PubMed

    Chen, Tsan-Ju; Hung, Hui-Shan; Wang, Dean-Chuan; Chen, Shun-Sheng

    2010-07-01

    Aluminum (Al) is a neurotoxicant and is implicated in several neurodegenerative diseases, including Alzheimer's disease (AD). In AD brains, one of the pathological hallmarks is the extracellular deposition of senile plaques, which are mainly composed of aggregated amyloid-beta (Abeta). Endoproteolysis of the amyloid-beta precursor protein (AbetaPP) by the beta-secretase and the gamma-secretase generates Abeta. AbetaPP can also be cleaved by the alpha-secretase within the Abeta region, which releases a soluble fragment sAPPalpha and precludes the formation of Abeta. Al has been reported to increase the level of Abeta, promote Abeta aggregation, and increase Abeta neurotoxicity. In contrast, small G protein Rho and its effector, Rho-associated kinase (ROCK), are known to negatively regulate the amount of Abeta. Inhibition of the Rho-ROCK pathway may underlie the ability of nonsteroidal anti-inflammatory drugs and statins to reduce Abeta production. Whether the Rho-ROCK pathway is involved in Al-induced elevation and aggregation of Abeta is unknown. In the present study, cultured rat cortical neurons were treated with Al(malt)(3) in the absence or presence of ROCK inhibitor Y-27632. After the treatment of Al(malt)(3), the cell viability and the level of sAPPalpha were reduced, whereas the amyloid fibrils in the conditioned media were increased. Treatment with Y-27632 prevented these adverse effects of Al(malt)(3) and thus maintained neuronal survival. These results reveal that the activation of the Rho-ROCK signaling pathway was involved in Al-induced effects in terms of the cell viability, the production of sAPPalpha, and the formation of amyloid fibril, which provides a novel mechanism underlying Al-induced neurotoxicity.

  19. The PARP inhibitor benzamide protects against kainate and NMDA but not AMPA lesioning of the mouse striatum in vivo.

    PubMed

    Cosi, Cristina; Guerin, Karen; Marien, Marc; Koek, Wouter; Rollet, Karin

    2004-01-16

    Overactivation of poly(ADP-ribose) polymerase (PARP) in response to genotoxic insults can cause cell death by energy deprivation. We previously reported that neurotoxic amounts of kainic acid (KA) injected into the rat striatum produce time-dependent changes in striatal PARP activity in vivo. Here, we have investigated the time-course of KA-induced toxicity and the effects of the PARP inhibitor benzamide on KA, AMPA and NMDA neurotoxicities in vivo, by measuring changes in the volume of the lesion and in NAD+ and ATP levels induced by the intra-striatal injection of these excitotoxins in C57Bl/6N mice. The KA-induced lesion volume was dependent on the amount of toxin injected and the survival time. The lesion was well developed at 48 h and was almost undetectable after one week. KA produced an extensive astrogliosis at one week. Benzamide partially prevented both KA- and NMDA- but not AMPA-induced lesions when measured at 48 h after the treatment. The effects of benzamide appeared to be in part related to changes in energy metabolism, since KA produced decreases in striatal levels of NAD+ and ATP that were partially prevented by benzamide at 48 h and which returned to control levels at one week. NMDA did not affect NAD+ and induced little alteration in ATP levels. Benzamide had no effect on AMPA-induced decreases in either NAD+ or ATP levels at 48 h. These results (1) indicate that PARP overactivation and energy depletion could be responsible in part for the cellular demise during the development of the lesion induced by KA; (2) confirm that PARP is involved in NMDA but not AMPA toxicities; (3) suggest the existence of differences between KA and AMPA-mediated toxicities; and (4) provide further evidence supporting PARP as a novel target for new drug treatments against neurodegenerative disorders.

  20. Neuronal loss and cytoskeletal disruption following intrahippocampal administration of the metabolic inhibitor malonate: lack of protection by MK-801.

    PubMed

    Pang, Z; Umberger, G H; Geddes, J W

    1996-02-01

    Impaired energy metabolism may contribute to the pathogenesis of late-onset neurodegenerative disorders such as Alzheimer's disease by increasing neuronal vulnerability to excitotoxic damage through the NMDA receptor. The effects of metabolic impairment on the striatum have been extensively examined, but relatively little is known regarding the vulnerability of the hippocampus. To examine the effect of metabolic impairment on the hippocampal formation, malonate (0.25-2.5 mumol), a reversible inhibitor of succinate dehydrogenase, was administered by stereotaxic injection into the hippocampus of male Sprague-Dawley rats. Neuronal loss was assessed by Nissl stain, and immunocytochemistry was used to examine cytoskeletal disruption. Malonate produced a dose-dependent lesion in which CA1 pyramidal neurons were most vulnerable, followed by CA3 and dentate gyrus. Cytoskeletal alterations included the loss of microtubule-associated protein 2 (MAP2) and dendritic MAP1B immunoreactivity, whereas axonal MAP1B and tau proteins were relatively spared. Spatially and temporally correlated with the loss of MAP2 was an increase in the immunoreactivity of calpain-cleaved spectrin. A similar pattern of neuronal damage and cytoskeletal disruption was produced by intrahippocampal injection of quinolinate (0.1 mumol), an NMDA agonist. Although these results are consistent with the hypothesis that metabolic impairment results in excitotoxic death, MK-801 (dizocilipine maleate), a noncompetitive NMDA receptor antagonist, did not attenuate the lesions produced by malonate but was effective against quinolinate. The results suggest that NMDA receptor activation is not required for malonate-induced damage in the hippocampal formation.

  1. Acute Coronary Syndromes, Gastrointestinal Protection, and Recommendations Regarding Concomitant Administration of Proton-Pump Inhibitors (Omeprazol/Esomeprazole) and Clopidogrel.

    PubMed

    Lozano, Iñigo; Sanchez-Insa, Esther; de Leiras, Sergio Rodríguez; Carrillo, Pilar; Ruiz-Quevedo, Valeriano; Pinar, Eduardo; Gopar-Gopar, Silvia; Bayon, Jeremías; Mañas, Pilar; Lasa, Garikoitz; CruzGonzalez, Ignacio; Hernandez, Felipe; Fernandez-Portales, Javier; Fernandez-Fernandez, Javier; Pérez-Serradilla, Ana; de la Torre Hernandez, José M; Gomez-Jaume, Alfredo

    2016-02-01

    The Food and Drug Administration and the European Medicines Agency sent a warning in 2010 discouraging the concomitant use of clopidogrel with omeprazole or esomeprazole. The purpose is to know the gastroprotective approach in patients with acute coronary syndrome (ACS) and the level of follow-up of the alert. In 17 hospitals with catheterization laboratory in Spain, 1 per region, we studied 25 consecutive patients per hospital whose diagnosis of discharge since October 1, 2013, had been any type of ACS. We analyzed their baseline clinical profile, the gatroprotective agents at admission and discharge and the antiplatelet therapy at discharge. The number of patients included was 425: age 67.2 ± 12.5 years, women 29.8%, diabetes 36.5%. The patients presented unstable angina in 21.6%, non-ST-elevation myocardial infarction in 35.3% and ST-elevation myocardial infarction in 43.1%. Conservative approach was chosen in 17.9%, bare-metal stents 32.2%, ≥ 1 drug-eluting stent 48.5%, and surgery 1.4%. Aspirin was indicated in 1.9%, aspirin + clopidogrel 73.6%, aspirin + prasugrel 17.6%, and aspririn + ticagrelor 6.8%. Gastroprotective agents were present in 40.2% patients at admission and this percentage increased to 93.7% at discharge. Of the 313 (73.6%) on clopidogrel in 96 (30.6%) was combined with omeprazole and 3 (0.95%) with esomeprazole, whereas the most commonly used was pantoprazole with 190 patients (44.7%). In conclusion, almost the totality of the patients with an ACS receive gastroprotective agents at the moment of discharge, most of them with proton-pump inhibitors. In one every 3 cases of the patients who are on clopidogrel, the recommendation of the Food and Drug Administration and the European Medicines Agency is not followed.

  2. Novel corrosion inhibitor technology

    SciTech Connect

    Van de Ven, P.; Fritz, P.; Pellet, R.

    1999-11-01

    A novel, patented corrosion inhibitor technology has been identified for use in heat transfer applications such as automotive and heavy-duty coolant. The new technology is based on a low-toxic, virtually depletion-free carboxylic acid corrosion inhibitor package that performs equally well in mono ethylene glycol and in less toxic propylene glycol coolants. An aqueous inhibitor concentrate is available to provide corrosion protection where freezing protection is not an issue. In the present paper, this inhibitor package is evaluated in the different base fluids: mono ethylene glycol, mono propylene glycol and water. Results are obtained in both standardized and specific corrosion tests as well as in selected field trials. These results indicate that the inhibitor package remains effective and retains the benefits previously identified in automotive engine coolant applications: excellent corrosion protection under localized conditions, general corrosion conditions as well as at high temperature.

  3. New amine-type inhibitors for protecting low-carbon steels in hydrogen sulfide-containing neutral media

    SciTech Connect

    Podobaev, N.I.; Atanasyan, T.K.; Lyashenko, L.F.; Isaev, M.G.; Sidorenko, G.V.

    1988-01-10

    The protecting action of polethylenepolyamine (PEPA) products was carried out by gravimetric and electrochemical methods in aerated and de-aerated 35 NaCl solutions and simulated waste water containing CaCl/sub 2/, NaCl, NaHCO/sub 3/, Na/sub 2/SO/sub 4/, and KBr, with addition of H/sub 2/S. Gravimetric and electrochemical measurements were carried out and results are presented. The influence on tanning agents on the physicomechanical and photographic properties of the positive emulsion Unibrom, Normal at thermostated aging for two days was shown. The results lead to the conclusion that the use of animals as tanning agents of the emulsion lead to improvement of the physicomechanical properties of the emulsion light sensitive layers.

  4. Protective effects of the nuclear factor kappa B inhibitor pyrrolidine dithiocarbamate in bladder ischemia-reperfusion injury in rats.

    PubMed

    Yucel, Mehmet; Kucuk, Aysegul; Bayraktar, Aslihan Cavunt; Tosun, Murat; Yalcinkaya, Soner; Hatipoglu, Namik Kemal; Erkasap, Nilufer; Kavutcu, Mustafa

    2013-10-01

    The aim of the present study was to evaluate the protective effects of the NF-кB inhibition with pyrrolidine-dithiocarbamate (PDTC) in ischemia-reperfusion (I/R) injury in the rat bladder. Twenty-four Sprague-Dawley male rats were divided into three groups. Group I; (n = 8) control, group II; (n = 8) I/R group; group III (n = 8) I/R and PDTC treatment. Superoxide dismutase (SOD), catalase (CAT), and gluatathione-S-transferase (GST) enzymes was studied in bladder tissue. Lipid peroxidation (as TBARS) levels in tissue homogenate were measured with thiobarbituric acid reaction. All the slides were stained with NF-кB, p53 and HSP60 immunohistochemistry for detection genome destruction and tissue stress, respectively. Our results show that the mean TBARS levels were significantly higher in group II (p < 0.05). The TBARS levels were significantly decreased in group III compared with the group II (p < 0.05). CAT, SOD and GST activities were decreased in group II, but these enzymes levels were significantly increased in group III according to the group II (p < 0.05). Under microscopic evaluation NF-кB expression increased significantly in group II compared to the group I (p < 0.05) and then decreased in group III (p < 0.05). HSP60 and p53 expression in group II was increased significantly compared with group I. Under microscopic evaluation we detected that HSP60 and p53 expression was increased significantly in group II compared with group I. In group III PDTC administration was decreased the HSP60 and p53 expression, this difference was statistically significant (p < 0.05). The results of the present study have demonstrated that NF-кB inhibition with PDTC protects and provides beneficial effects on ischemia/reperfusion stress related bladder tissue destruction.

  5. The Specific Protein Kinase R (PKR) Inhibitor C16 Protects Neonatal Hypoxia-Ischemia Brain Damages by Inhibiting Neuroinflammation in a Neonatal Rat Model

    PubMed Central

    Xiao, Jinglei; Tan, Yongchang; Li, Yinjiao; Luo, Yan

    2016-01-01

    Background Brain injuries induced by hypoxia-ischemia in neonates contribute to increased mortality and lifelong neurological dysfunction. The specific PKR inhibitor C16 has been previously demonstrated to exert a neuroprotective role in adult brain injuries. However, there is no recent study available concerning its protective role in hypoxia-ischemia-induced immature brain damage. Therefore, we investigated whether C16 protects against neonatal hypoxia-ischemia injuries in a neonatal rat model. Material/Methods Postnatal day 7 (P7) rats were used to establish classical hypoxia-ischemia animal models, and C16 postconditioning with 100 ug/kg was performed immediately after hypoxia. Western blot analysis was performed to quantify the phosphorylation of the PKR at 0 h, 3 h, 6 h, 12 h, 24 h, and phosphorylation of NF-κB 24h after hypoxia exposure. The TTC stain for infarction area and TUNEL stain for apoptotic cells were assayed 24 h after the brain hypoxia. Gene expression of IL-1β, IL-6, and TNF-α was performed at 3 h, 6 h, 12 h, and 24 h. Results The level of PKR autophosphorylation was increased dramatically, especially at 3 h (C16 group vs. HI group, P<0.01). Intraperitoneal C16 administration reduced the infarct volume and apoptosis ratio after this insult (C16 group vs. HI group<0.01), and C16 reduced proinflammatory cytokines mRNA expression, partly through inhibiting NF-κB activation (C16 group vs. HI group<0.05). Conclusions C16 can protect immature rats against hypoxia-ischemia-induced brain damage by modulating neuroinflammation. PMID:28008894

  6. Insulinotropic and β-cell protective action of cuminaldehyde, cuminol and an inhibitor isolated from Cuminum cyminum in streptozotocin-induced diabetic rats.

    PubMed

    Patil, Swapnil B; Takalikar, Shreehari S; Joglekar, Madhav M; Haldavnekar, Vivek S; Arvindekar, Akalpita U

    2013-10-01

    Cuminum cyminum, a commonly used spice, is known to have anti-diabetic action. The present study aims towards the isolation of bioactive components from C. cyminum and the evaluation of their insulin secretagogue potential with the probable mechanism and β-cell protective action. The anti-diabetic activity was detected in the petroleum ether (pet ether) fraction of the C. cyminum distillate and studied through in vivo and in vitro experiments. Bioactive components were identified through GC-MS, Fourier transform infrared spectroscopy and NMR analysis. The isolated components were evaluated for their insulin secretagogue action using rat pancreatic islets. Further, the probable mechanism of stimulation of islets was evaluated through in vitro studies using diazoxide, nifedipine and 3-isobutyl-1-methylxanthine. β-Cell protection was evaluated using the (1-(4,5-dimethylthiazol-2-yl)-3,5-diphenylformazan) (MTT) assay, the alkaline comet assay and nitrite production. The administration of the pet ether fraction for 45 d to streptozotocin-induced diabetic rats revealed an improved lipid profile. Cuminaldehyde and cuminol were identified as potent insulinotrophic components. Cuminaldehyde and cuminol (25 μg/ml) showed 3·34- and 3·85-fold increased insulin secretion, respectively, than the 11·8 mm-glucose control. The insulinotrophic action of both components was glucose-dependent and due to the closure of the ATP-sensitive K (K⁺-ATP) channel and the increase in intracellular Ca²⁺ concentration. An inhibitor of insulin secretion with potent β-cell protective action was also isolated from the same pet ether fraction. In conclusion, C. cyminum was able to lower blood glucose without causing hypoglycaemia or β-cell burn out. Hence, the commonly used spice, C. cyminum, has the potential to be used as a novel insulinotrophic therapy for prolonged treatment of diabetes.

  7. Histone deacetylase inhibitors sensitize lung cancer cells to hyperthermia: involvement of Ku70/SirT-1 in thermo-protection.

    PubMed

    Hassan, Mohamed K; Watari, Hidemichi; Salah-Eldin, Alaa-Eldin; Sultan, Ahmed S; Mohamed, Zainab; Fujioka, Yoichiro; Ohba, Yusuke; Sakuragi, Noriaki

    2014-01-01

    This study describes the sensitization mechanism to thermal stress by histone deacetylase inhibitors (HDACIs) in lung cancer cells and shows that Ku70, based on its acetylation status, mediates the protection of lung cancer from hyperthermia (42.5°C, 1-6 hrs). Ku70 regulates apoptosis by sequestering pro-apoptotic Bax. However, its role in thermal stress is not fully understood. The findings showed that, pre-treating lung cancer cells with HDACIs, nicotinamide (NM) or Trichostatin A (TsA) or both significantly enhanced hyperthermia-induced Bax-dependent apoptosis in PC-10 cells. We found that hyperthermia induces SirT-1, Sirtuin, upregulation but not HDAC6 or SirT-3, therefore transfection with dominant negative SirT-1 (Y/H) also eliminated the protection and resulted in more cell death by hyperthermia, in H1299 cells through Bax activation. Hyperthermia alone primed lung cancer cells to apoptosis without prominent death. After hyperthermia Bax was upregulated, Bcl-2 was downregulated, the Bax/Bcl-2 ratio was inversed and Bax/Bcl-2 heterodimer was dissociated. Although hyperthermia did not affect total Ku70 expression level, it stimulated Ku70 deacetylation, which in turn could bind more Bax in the PC-10 cells. These findings suggest an escape mechanism from hyperthermia-induced Bax activation. To verify the role of Ku70 in this protection mechanism, Ku70 was silenced by siRNA. Ku70 silencing significantly sensitized the lung cancer cells to hyperthermia. The Ku70 KD cells underwent cytotoxic G1 arrest and caspase-dependant apoptosis when compared to scrambled transfectants which showed only G2/M cytostatic arrest in the cell lines investigated, suggesting an additional cell cycle-dependent, novel, role of Ku70 in protection from hyperthermia. Taken together, our data show a Ku70-dependent protection mechanism from hyperthermia. Targeting Ku70 and/or its acetylation during hyperthermia may represent a promising therapeutic approach for lung cancer.

  8. Histone Deacetylase Inhibitors Sensitize Lung Cancer Cells to Hyperthermia: Involvement of Ku70/SirT-1 in Thermo-Protection

    PubMed Central

    Hassan, Mohamed K.; Watari, Hidemichi; Salah-eldin, Alaa-eldin; Sultan, Ahmed S.; Mohamed, Zainab; Fujioka, Yoichiro; Ohba, Yusuke; Sakuragi, Noriaki

    2014-01-01

    This study describes the sensitization mechanism to thermal stress by histone deacetylase inhibitors (HDACIs) in lung cancer cells and shows that Ku70, based on its acetylation status, mediates the protection of lung cancer from hyperthermia (42.5°C, 1-6 hrs). Ku70 regulates apoptosis by sequestering pro-apoptotic Bax. However, its role in thermal stress is not fully understood. The findings showed that, pre-treating lung cancer cells with HDACIs, nicotinamide (NM) or Trichostatin A (TsA) or both significantly enhanced hyperthermia-induced Bax-dependent apoptosis in PC-10 cells. We found that hyperthermia induces SirT-1, Sirtuin, upregulation but not HDAC6 or SirT-3, therefore transfection with dominant negative SirT-1 (Y/H) also eliminated the protection and resulted in more cell death by hyperthermia, in H1299 cells through Bax activation. Hyperthermia alone primed lung cancer cells to apoptosis without prominent death. After hyperthermia Bax was upregulated, Bcl-2 was downregulated, the Bax/Bcl-2 ratio was inversed and Bax/Bcl-2 heterodimer was dissociated. Although hyperthermia did not affect total Ku70 expression level, it stimulated Ku70 deacetylation, which in turn could bind more Bax in the PC-10 cells. These findings suggest an escape mechanism from hyperthermia-induced Bax activation. To verify the role of Ku70 in this protection mechanism, Ku70 was silenced by siRNA. Ku70 silencing significantly sensitized the lung cancer cells to hyperthermia. The Ku70 KD cells underwent cytotoxic G1 arrest and caspase-dependant apoptosis when compared to scrambled transfectants which showed only G2/M cytostatic arrest in the cell lines investigated, suggesting an additional cell cycle-dependent, novel, role of Ku70 in protection from hyperthermia. Taken together, our data show a Ku70-dependent protection mechanism from hyperthermia. Targeting Ku70 and/or its acetylation during hyperthermia may represent a promising therapeutic approach for lung cancer. PMID:24728004

  9. Protective Effect of Infliximab, a Tumor Necrosis Factor-Alfa Inhibitor, on Bleomycin-Induced Lung Fibrosis in Rats.

    PubMed

    Altintas, Nejat; Erboga, Mustafa; Aktas, Cevat; Bilir, Bulent; Aydin, Murat; Sengul, Aysun; Ates, Zehra; Topcu, Birol; Gurel, Ahmet

    2016-02-01

    We aimed to investigate the preventive effect of Infliximab (IFX), a tumor necrosis factor (TNF)-α inhibitor, on bleomycin (BLC)-induced lung fibrosis in rats. Rats were assigned into four groups as follows: I-BLC group, a single intra-tracheal BLC (2.5 mg/kg) was installed; II-control group, a single intra-tracheal saline was installed; III-IFX + BLC group, a single-dose IFX (7 mg/kg) was administered intraperitoneally (i.p.), 72 h before the intra-tracheal BLC installation; IV-IFX group, IFX (7 mg/kg) was administered alone i.p. on the same day with IFX + BLC group. All animals were sacrificed on the 14th day of BLC installation. Levels of tumor necrosis factor (TNF)-α, transforming growth factor (TGF)-β, interleukin (IL)-6, periostin, YKL-40, nitric oxide (NO) in rat serum were measured, as well as, myeloperoxidase (MPO), superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx) activity, and reduced glutathione (GSH), hydroxyproline, malondialdehyde (MDA) content in lung homogenates. Lung tissues were stained with hematoxylin and eosin (H&E) for quantitative histological evaluation. The inducible nitric oxide synthase (iNOS) expression and cell apoptosis in the lung tissues were determined quantitatively by immunohistochemical staining (INOS) and by TUNNEL staining, respectively. BLC installation worsened antioxidant status (such as SOD, CAT, GPx, GSH, MPO), while it increased the serum TNF-α, TGF-β, IL-6, periostin, YKL-40, and lipid peroxidation, and collagen deposition, measured by MDA and hydroxyproline, respectively. IFX pretreatment improved antioxidant status as well as BLC-induced lung pathological changes, while it decreased the TNF-α, TGF-β, IL-6, periostin, YKL-40, lipid peroxidation and collagen deposition. Finally, histological, immunohistochemical, and TUNNEL evidence also supported the ability of IFX to prevent BLC-induced lung fibrosis. The results of the present study indicate that IFX pretreatment can attenuate

  10. Small Molecular Inhibitor of Transforming Growth Factor-{beta} Protects Against Development of Radiation-Induced Lung Injury

    SciTech Connect

    Anscher, Mitchell S. Thrasher, Bradley; Zgonjanin, Larisa; Rabbani, Zahid N.; Corbley, Michael J.; Fu Kai; Sun Lihong; Lee, W.-C.; Ling, Leona E.; Vujaskovic, Zeljko

    2008-07-01

    Purpose: To determine whether an anti-transforming growth factor-{beta} (TGF-{beta}) type 1 receptor inhibitor (SM16) can prevent radiation-induced lung injury. Methods and Materials: One fraction of 28 Gy or sham radiotherapy (RT) was administered to the right hemithorax of Sprague-Dawley rats. SM16 was administered in the rat chow (0.07 g/kg or 0.15 g/kg) beginning 7 days before RT. The rats were divided into eight groups: group 1, control chow; group 2, SM16, 0.07 g/kg; group 3, SM16, 0.15 g/kg; group 4, RT plus control chow; group 5, RT plus SM16, 0.07 g/kg; group 6, RT plus SM16, 0.15 g/kg; group 7, RT plus 3 weeks of SM16 0.07 g/kg followed by control chow; and group 8, RT plus 3 weeks of SM16 0.15 g/kg followed by control chow. The breathing frequencies, presence of inflammation/fibrosis, activation of macrophages, and expression/activation of TGF-{beta} were assessed. Results: The breathing frequencies in the RT plus SM16 0.15 g/kg were significantly lower than the RT plus control chow from Weeks 10-22 (p <0.05). The breathing frequencies in the RT plus SM16 0.07 g/kg group were significantly lower only at Weeks 10, 14, and 20. At 26 weeks after RT, the RT plus SM16 0.15 g/kg group experienced a significant decrease in lung fibrosis (p = 0.016), inflammatory response (p = 0.006), and TGF-{beta}1 activity (p = 0.011). No significant reduction was found in these measures of lung injury in the group that received SM16 0.7g/kg nor for the short-course (3 weeks) SM16 at either dose level. Conclusion: SM16 at a dose of 0.15 g/kg reduced functional lung damage, morphologic changes, inflammatory response, and activation of TGF-{beta} at 26 weeks after RT. The data suggest a dose response and also suggest the superiority of long-term vs. short-term dosing.

  11. beta1-integrin mediates asbestos-induced phosphorylation of AKT and ERK1/2 in a rat pleural mesothelial cell line.

    PubMed

    Berken, Antje; Abel, Josef; Unfried, Klaus

    2003-11-20

    Integrin-mediated signalling has been implicated in asbestos-induced carcinogenesis. In studies here, we examined signal transduction events associated with integrin-directed cell reactions triggered by crocidolite asbestos in the pleural mesothelial cell line 4/4 RM-4. Crocidolite fibres induced a significant time- and dose-dependent activation of the extracellular-signal-regulated kinases ERK1 and ERK2. ERK activation was specifically inhibited by integrin-blocking agents, that are integrin-binding peptides containing the sequence arginine-glycine-aspartic acid (RGD), and monoclonal antibodies against the integrin beta1-chain. Integrin-dependent activation of ERK1/2 in response to asbestos appeared to be independent of focal adhesion kinase pp125FAK (FAK) since FAK autophosphorylation remained unaffected in crocidolite-exposed mesothelial cells. Instead, we observed striking similarities in the kinetics of asbestos-induced ERK1/2 responses and phosphorylation of protein kinase B (AKT) at serine 473, a possible target residue for integrin-linked kinase. As with ERK activation, asbestos-induced AKT stimulation was significantly blocked by both the RGD-peptide and the beta1-integrin antibodies. These studies are the first to establish that in mesothelial cells ERK1/2 and AKT are simultaneously phosphorylated upon asbestos exposure in a beta1-integrin-dependent manner.

  12. The crocidolite fibres interaction with human mesothelial cells as investigated by combining electron microscopy, atomic force and scanning near-field optical microscopy.

    PubMed

    Andolfi, Laura; Trevisan, Elisa; Zweyer, Marina; Prato, Stefano; Troian, Barbara; Vita, Francesca; Borelli, Violetta; Soranzo, Maria Rosa; Melato, Mauro; Zabucchi, Giuliano

    2013-03-01

    In this study, we have performed a morphological analysis of crocidolite fibres interaction with mesothelial cells (MET5A) by combining conventional electron microscopy with atomic force (AFM) and scanning near-field optical microscopy (SNOM). After 6-h exposure at a crocidolite dose of 5 μg cm(-2), 90% of MET5A cells interact with fibres that under these conditions have a low cytotoxic effect. SEM images point out that fibres can be either engulfed by the cells that lose their typical morphology or they can accumulate over or partially inside the cells, which preserve their typical spread morphology. By using AFM we are able to directly visualize the entry-site of nanometric-sized fibres at the plasma membrane of the spread mesothelial cells. More importantly, the crocidolite fibres that are observed to penetrate the plasma membrane in SNOM topography can be simultaneously followed beneath the cell surface in the SNOM optical images. The analysis of SNOM data demonstrates the entrance of crocidolite fibres in proximity of nuclear compartment, as observed also in the TEM images. Our findings indicate that the combination of conventional electron microscopy with novel nanoscopic techniques can be considered a promising approach to achieve a comprehensive morphological description of the interaction between asbestos fibres and mesothelial cells that represents the early event in fibre pathogenesis.

  13. Protection from inorganic mercury effects on the in vivo dopamine release by ionotropic glutamate receptor antagonists and nitric oxide synthase inhibitors.

    PubMed

    Vidal, Lucía; Durán, Rafael; Faro, Lilian F; Campos, Francisco; Cervantes, Rosa C; Alfonso, Miguel

    2007-09-05

    The possible role of ionotropics glutamate receptors on the HgCl(2)-induced dopamine (DA) release from rat striatum was investigated by using in vivo brain microdialysis technique after administration of selective NMDA and AMPA/Kainate receptors antagonists dizocilpine (MK-801), D (-)-2-amino-5-phoshonopentanoic acid (AP5), and 6-cyano-7-nitroquinoxaline-2,3-dione (CNQX). Moreover, we have also studied the effects of nitric oxide synthase (NOS) inhibitors L-nitro-arginine methyl ester (L-NAME) and 7-nitro-indazol (7-NI) on HgCl(2)-induced DA release. Intraestriatal infusion of 1mM HgCl(2) increased striatal DA to 1717.2+/-375.4% respect to basal levels. Infusion of 1mM HgCl(2) in 400 microM MK-801 pre-treated animals produced an increase on striatal DA levels 61% smaller than that induced in non-pre-treated animals. In the case of AP5, this treatment reduced 92% the increase produced by HgCl(2) as compared to non-pre-treated rats. Nevertheless, the administration of CNQX did not produce any effect on HgCl(2)-induced dopamine release. Intrastriatal infusion of 1mM HgCl(2) in 100 microM L-NAME pre-treated animals produced an increase on extracellular DA levels 82% smaller than produced by HgCl(2) alone. In addition, the pre-treatment with 7-NI reduced 90% the increase produced by infusion of HgCl(2) alone in rats. Thus, HgCl(2)-induced DA release could be produced at last in part, by overstimulation of NMDA receptors with NO production, since administration of NMDA receptor antagonists and NOS inhibitors protected against HgCl(2) effects on DA release.

  14. Protective Role for Tissue Inhibitor of Metalloproteinase-4, a Novel Peroxisome Proliferator-Activated Receptor-γ Target Gene, in Smooth Muscle in Deoxycorticosterone Acetate-Salt Hypertension.

    PubMed

    Ketsawatsomkron, Pimonrat; Keen, Henry L; Davis, Deborah R; Lu, Ko-Ting; Stump, Madeliene; De Silva, T Michael; Hilzendeger, Aline M; Grobe, Justin L; Faraci, Frank M; Sigmund, Curt D

    2016-01-01

    Loss of peroxisome proliferator-activated receptor-γ (PPARγ) function causes hypertension, whereas its activation lowers blood pressure. Evidence suggests that these effects may be attributable to PPARγ activity in the vasculature. However, the specific transcriptional targets of PPARγ in vessels remain largely unidentified. In this study, we examined the role of smooth muscle PPARγ during salt-sensitive hypertension and investigated its transcriptional targets and functional effect. Transgenic mice expressing dominant-negative PPARγ (S-P467L) in smooth muscle cells were more prone to deoxycorticosterone acetate-salt-induced hypertension and mesenteric arterial dysfunction compared with nontransgenic controls. Despite similar morphometry at baseline, vascular remodeling in conduit and small arteries was enhanced in S-P467L after deoxycorticosterone acetate-salt treatment. Gene expression profiling in aorta and mesenteric arteries revealed significantly decreased expression of tissue inhibitor of metalloproteinase-4 (TIMP-4) in S-P467L. Expression of TIMP-4 was increased by deoxycorticosterone acetate-salt treatment, but this increase was ablated in S-P467L. Interference with PPARγ activity either by treatment with a PPARγ inhibitor, GW9662, or by expressing P467L PPARγ markedly suppressed TIMP-4 in primary smooth muscle cells. PPARγ binds to a PPAR response element (PPRE) in chromatin close to the TIMP-4 gene in smooth muscle cells, suggesting that TIMP-4 is a novel target of PPARγ. The interference with PPARγ and decrease in TIMP-4 were accompanied by an increase in total matrix metalloproteinase activity. PPARγ-mediated loss of TIMP-4 increased, whereas overexpression of TIMP-4 decreased smooth muscle cell migration in a scratch assay. Our findings highlight a protective mechanism induced by PPARγ in deoxycorticosterone acetate-salt treatment, establishing a novel mechanistic link between PPARγ and TIMP-4.

  15. Ocular Inflammation and Corneal Permeability Alteration by Benzalkonium Chloride in Rats: A Protective Effect of a Myosin Light Chain Kinase Inhibitor

    PubMed Central

    Droy-Lefaix, Marie Thérèse; Bueno, Lionel; Caron, Philippe; Belot, Eric; Roche, Olivier

    2013-01-01

    Purpose. The aim of this study was to evaluate the interest of an ophthalmic eyedrop preparation containing a myosin light chain kinase (MLCK) inhibitor, ML-7, in the treatment of ocular surface. The local protective effect on the inflammation and the increase of corneal permeability induced by benzalkonium (BAK) was evaluated. Methods. An ocular instillation of 10 μL BAK at a concentration of 0.1% in PBS was performed on rats. The eyes were rinsed with sterilized water, 10 minutes after BAK preceded by instillation at T −24, −12, and −0.5 hours of 10 μL of ML-7: 100 μg (10 μL) into a gel form vehicle. All animals were sacrificed 6 hours after BAK instillation. The eyes were isolated for study in a masked manner. The ocular surface inflammation was assessed by measuring the inflammatory cell infiltration by a histologic quantitative analysis and for total ocular myeloperoxidase (MPO) activity. The tight junction permeability was tested. Results. Instillation of 0.1% BAK increased the inflammation of the eye. The quantitative analysis showed an increase in the number of eosinophil and neutrophil polynuclears, and MPO activity. Pretreatment with ML-7 reduced inflammation (P < 0.05). The vehicle alone produced no notable effects. BAK instillation also thickened the fluorescent corneal front on frozen sections, indicating an increase of tight junction permeability. Pretreatment with ML-7 suppressed BAK-induced alterations of paracellular permeability while the vehicle had no visible effects. Conclusions. Our study indicates that the inhibition of corneal cytoskeleton contraction by an MLCK inhibitor prevents BAK-induced ocular inflammatory response, and that ML-7 may be a new and original preparation in the treatment of ocular surface pathologies. PMID:23518768

  16. The 5α-reductase inhibitor Dutasteride but not Finasteride protects dopamine neurons in the MPTP mouse model of Parkinson's disease.

    PubMed

    Litim, Nadhir; Bourque, Mélanie; Al Sweidi, Sara; Morissette, Marc; Di Paolo, Thérèse

    2015-10-01

    Finasteride and Dutasteride are 5α-reductase inhibitors used in the clinic to treat endocrine conditions and were recently found to modulate brain dopamine (DA) neurotransmission and motor behavior. We investigated if Finasteride and Dutasteride have a neuroprotective effect in 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) male mice as a model of Parkinson's disease (PD). Experimental groups included saline treated controls and mice treated with saline, Finasteride (5 and 12.5 mg/kg) or Dutasteride (5 and 12.5 mg/kg) for 5 days before and 5 days after MPTP administration (4 MPTP injections, 6.5 mg/kg on day 5 inducing a moderate DA depletion) and then they were euthanized. MPTP administration decreased striatal DA contents measured by HPLC while serotonin contents remained unchanged. MPTP mice treated with Dutasteride 5 and 12.5 mg/kg had higher striatal DA and metabolites (DOPAC and HVA) contents with a decrease of metabolites/DA ratios compared to saline-treated MPTP mice. Finasteride had no protective effect on striatal DA contents. Tyrosine hydroxylase (TH) mRNA levels measured by in situ hybridization in the substantia nigra pars compacta were unchanged. Dutasteride at 12.5 mg/kg reduced the effect of MPTP on specific binding to striatal DA transporter (DAT) and vesicular monoamine transporter 2 (VMAT2) measured by autoradiography. MPTP reduced compared to controls plasma testosterone (T) and dihydrotestosterone (DHT) concentrations measured by liquid chromatography-tandem mass spectrometry; Dutasteride and Finasteride increased plasma T levels while DHT levels remained low. In summary, our results showed that a 5α-reductase inhibitor, Dutasteride has neuroprotective activity preventing in male mice the MPTP-induced loss of several dopaminergic markers.

  17. Synthesis of the novel PARP-1 inhibitor AG-690/11026014 and its protective effects on angiotensin II-induced mouse cardiac remodeling.

    PubMed

    Feng, Guo-Shuai; Zhu, Cui-Ge; Li, Zhuo-Ming; Wang, Pan-Xia; Huang, Yi; Liu, Min; He, Ping; Lou, Lan-Lan; Chen, Shao-Rui; Liu, Pei-Qing

    2017-02-27

    We previously identified AG-690/11026014 (6014) as a novel poly(ADP-ribose) polymerase-1 (PARP-1) inhibitor that effectively prevented angiotensin II (Ang II)-induced cardiomyocyte hypertrophy. In the present study, we reported a new synthesis route for 6014, and investigated its protective effects on Ang II-induced cardiac remodeling and cardiac dysfunction and the underlying mechanisms in mice. We designed a new synthesis route to obtain a sufficient quantity of 6014 for this in vivo study. C57BL/6J mice were infused with Ang II and treated with 6014 (10, 30, 90 mg·kg(-1)·d(-1), ig) for 4 weeks. Then two-dimensional echocardiography was performed to assess the cardiac function and structure. Histological changes of the hearts were examined with HE staining and Masson's trichrome staining. The protein expression was evaluated by Western blot, immunohistochemistry and immunofluorescence assays. The activities of sirtuin-1 (SIRT-1) and the content of NAD+ were detected with the corresponding test kits. Treatment with 6014 dose-dependently improved cardiac function, including LVEF, CO and SV and reversed the changes of cardiac structure in Ang II-infused mice: it significantly ameliorated Ang II-induced cardiac hypertrophy evidenced by attenuating the enlargement of cardiomyocytes, decreased HW/BW and LVW/BW, and decreased expression of hypertrophic markers ANF, BNP and β-MHC; it also prevented Ang II-induced cardiac fibrosis, as implied by the decrease in excess accumulation of extracellular matrix (ECM) components collagen I, collagen III and FN. Further studies revealed that treatment with 6014 did not affect the expression levels of PARP-1, but dose-dependently inhibited the activity of PARP-1 and subsequently restored the activity of SIRT-1 in heart tissues due to the decreased consumption of NAD+ and attenuated Poly-ADP-ribosylation (PARylation) of SIRT-1. In conclusion, the novel PARP-1 inhibitor 6014 effectively protects mice against AngII-induced cardiac

  18. Mesothelial Cell Autoantibodies Induce Collagen Deposition in vitro & Using a Case Study to Introduce Undergraduates to Bioinformatics

    NASA Astrophysics Data System (ADS)

    Serve, Kinta M.

    Part I. Pleural fibrosis, a non-malignant, asbestos-related respiratory disease characterized by excessive collagen deposition, is progressive, debilitating, and potentially fatal. Disease severity may be influenced by the type of asbestos fiber inhaled, with Libby amphibole (LA) a seemingly more potent mediator of pleural fibrosis than chrysotile (CH) asbestos. This difference in severity may be due to the reported immunological component associated with LA but not CH related diseases. Here, we report the potential mechanisms by which asbestos-associated mesothelial cell autoantibodies (MCAAs) contribute to pleural fibrosis development. MCAAs are shown to bind cultured human pleural mesothelial cells and induce the deposition of type I collagen proteins in the absence of phenotypic changes typically associated with fibrosis development. However, additional extracellular proteins seem to differentially contribute to LA and CH MCAA-associated collagen deposition. Our data also suggest that IgG subclass distributions differ between LA and CH MCAAs, potentially altering the antibody effector functions. Differences in MCAA mechanisms of action and effector functions may help explain the disparate clinical disease phenotypes noted between LA and CH-exposed populations and may provide insights for development of novel therapeutic strategies. Part II. As scientific research becomes increasingly reliant on computational tools, it is more important than ever before to train students to use these tools. While educators agree that biology students should gain experience with bioinformatics, there exists no consensus as to how to integrate these concepts into the already demanding undergraduate curriculum. The Portal-21 project offers a solution by utilizing on-line learning case studies to allow flexibility for classroom integration. Presented here are the results from two field tests of a case study developed to introduce the common bioinformatics tools pBLAST and PubMed to

  19. Biocompatibility versus peritoneal mesothelial cells of polypropylene prostheses for hernia repair, coated with a thin silica/silver layer.

    PubMed

    Muzio, Giuliana; Perero, Sergio; Miola, Marta; Oraldi, Manuela; Ferraris, Sara; Vernè, Enrica; Festa, Federico; Canuto, Rosa Angela; Festa, Valentino; Ferraris, Monica

    2016-04-29

    Hernias are generally repaired using synthetic prostheses. Infection may already be present or develop during implantation. Based on the increasing resistance to antibiotics, and the well-known antimicrobial properties of silver (Ag), the possibility of coating hernia prostheses with a nanostructured layer containing Ag was explored. Prostheses (Clear Mesh Composite [CMC]) made up of two polypropylene layers (macroporous light mesh and thin transparent film) were tested with human mesothelial cells from omentum biopsies. Mesotheliocytes modulate abdominal wall healing producing cytokines, growth factors, and adhesion molecules. Evaluating the growth of these cells on CMC or film alone showed that cell numbers on CMC increased over time, and were higher than those on film alone. Vimentin immunostaining confirmed the cells to be mesotheliocytes. Subsequently, the biocompatibility of mesh layer, coated or not with a thin layer of Ag/SiO2 -nanoclusters, was analyzed, showing no difference in absence or presence of Ag/SiO2 . Differently, TGF-β2 production, involved in tissue repair and fibrosis, increased in the presence of Ag/SiO2 . Moreover, Ag/SiO2 -coated mesh showed antibacterial properties. In conclusion, the mesh layer coated with Ag/SiO2 afforded cell growth, and showed antibacterial activity. Coating only the mesh layer did not decrease film transparency, and did not favor the formation of adhesions on the visceral side. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2016.

  20. Cytotoxic and oxidative effects induced by man-made vitreous fibers (MMVFs) in a human mesothelial cell line.

    PubMed

    Cavallo, Delia; Campopiano, Antonella; Cardinali, Giorgia; Casciardi, Stefano; De Simone, Paolo; Kovacs, Daniela; Perniconi, Barbara; Spagnoli, Giuseppe; Ursini, Cinzia L; Fanizza, Carla

    2004-09-01

    The introduction of man-made vitreous fibers (MMVFs) as a substitute for asbestos in industrial and residential applications raises concerns about their potential health hazards. The aim of our study was to assess cytotoxic and oxidative effects induced on a human mesothelial cell line (MeT-5A) by exposure to glass wool (GW), rock wool (RW) and refractory ceramic fibers (RCF) in comparison with crocidolite asbestos (CR). MeT-5A cells were exposed for 24 h to 2, 5 and 10 microg/cm2 of MMVF and crocidolite fibers and analysed by scanning electron microscope (SEM) for cell surface alterations. Cells were exposed for 2 h to 1, 2, 5 and 10 microg/cm2 of the same fibers and analysed by enzyme Fpg-modified comet test for direct and oxidative DNA damage. SEM revealed loss of microvilli in cells exposed to RCF and numerous blebs in cells exposed to higher doses of RW. Comet test showed significant direct DNA damage in cells exposed to RCF even at the lowest dose. Comet test with Fpg, that permits the detection of oxided DNA bases, showed significant oxidative DNA damage in cells exposed to higher doses of RW. The presence of DNA damage and alterations of cell surface induced by low doses of RCF and the presence of oxidative DNA damage and blebs on cell surface in cells exposed to higher dose of RW suggest possible cytotoxic, oxidative and genotoxic effects for these MMVFs.

  1. Correlations Between Hector Battifora Mesothelial-1 (HBME-1) Expression and Clinical Pathological Characteristics and Prognosis of Osteosarcoma Patients

    PubMed Central

    Zhao, Yu-Xin; Gao, Song-Tao; Wang, Jia-Qiang; Yao, Wei-Tao; Wang, Yi-Sheng; Guo, Cai-Li

    2017-01-01

    Background The aim of this study was to investigate the correlation between Hector Battifora mesothelial-1 (HBME-1) expression and the clinical pathological characteristics and prognosis of osteosarcoma (OS). Material/Methods HBME-1 expression was assessed using immunohistochemistry in OS tissues (n=152), osteochondroma tissues (n=91), and normal bone tissues (n=74). We carried out a follow-up lasting 8–60 months to investigate HBME-1 expression and its correlations with the clinical pathological characteristics and prognosis of OS. Results HBME-1 was highly expressed in OS tissues compared with osteochondroma tissues and normal bone tissues, and was highly expressed in osteochondroma tissues compared with normal bone tissues (all P<0.05). HBME-1 expression was correlated with clinical stages, postoperative recurrence, metastasis, and 5-year survival (all P<0.05). The area under the receiver operating characteristics curve of HBME-1 expression was 0.864, with sensitivity of 80.92%, specificity of 91.89%, and accuracy of 84.51%. The survival rate was lower in the HBME-1 positive expression group than the HBME-1 negative expression group (P<0.05). Clinical stages, metastasis, and HBME-1 expression were independent risk factors for the survival of patients with OS (all P<0.05). Conclusions HBME-1 expression was correlated with the occurrence and development of OS. HBME-1 positive expression was a risk factor for the prognosis of OS. PMID:28163298

  2. Continuous Exposure to Chrysotile Asbestos Can Cause Transformation of Human Mesothelial Cells via HMGB1 and TNF-α Signaling

    PubMed Central

    Qi, Fang; Okimoto, Gordon; Jube, Sandro; Napolitano, Andrea; Pass, Harvey I.; Laczko, Rozalia; DeMay, Richard M.; Khan, Ghazal; Tiirikainen, Maarit; Rinaudo, Caterina; Croce, Alessandro; Yang, Haining; Gaudino, Giovanni; Carbone, Michele

    2014-01-01

    Malignant mesothelioma is strongly associated with asbestos exposure. Among asbestos fibers, crocidolite is considered the most and chrysotile the least oncogenic. Chrysotile accounts for more than 90% of the asbestos used worldwide, but its capacity to induce malignant mesothelioma is still debated. We found that chrysotile and crocidolite exposures have similar effects on human mesothelial cells. Morphological and molecular alterations suggestive of epithelial–mesenchymal transition, such as E-cadherin down-regulation and β-catenin phosphorylation followed by nuclear translocation, were induced by both chrysotile and crocidolite. Gene expression profiling revealed high-mobility group box-1 protein (HMGB1) as a key regulator of the transcriptional alterations induced by both types of asbestos. Crocidolite and chrysotile induced differential expression of 438 out of 28,869 genes interrogated by oligonucleotide microarrays. Out of these 438 genes, 57 were associated with inflammatory and immune response and cancer, and 14 were HMGB1 targeted genes. Crocidolite-induced gene alterations were sustained, whereas chrysotile-induced gene alterations returned to background levels within 5 weeks. Similarly, HMGB1 release in vivo progressively increased for 10 or more weeks after crocidolite exposure, but returned to background levels within 8 weeks after chrysotile exposure. Continuous administration of chrysotile was required for sustained high serum levels of HMGB1. These data support the hypothesis that differences in biopersistence influence the biological activities of these two asbestos fibers. PMID:24160326

  3. Exclusive rewards in mutualisms: ant proteases and plant protease inhibitors create a lock-key system to protect Acacia food bodies from exploitation.

    PubMed

    Orona-Tamayo, Domancar; Wielsch, Natalie; Blanco-Labra, Alejandro; Svatos, Ales; Farías-Rodríguez, Rodolfo; Heil, Martin

    2013-08-01

    Myrmecophytic Acacia species produce food bodies (FBs) to nourish ants of the Pseudomyrmex ferrugineus group, with which they live in an obligate mutualism. We investigated how the FBs are protected from exploiting nonmutualists. Two-dimensional gel electrophoresis of the FB proteomes and consecutive protein sequencing indicated the presence of several Kunitz-type protease inhibitors (PIs). PIs extracted from Acacia FBs were biologically active, as they effectively reduced the trypsin-like and elastase-like proteolytic activity in the guts of seed-feeding beetles (Prostephanus truncatus and Zabrotes subfasciatus), which were used as nonadapted herbivores representing potential exploiters. By contrast, the legitimate mutualistic consumers maintained high proteolytic activity dominated by chymotrypsin 1, which was insensitive to the FB PIs. Larvae of an exploiter ant (Pseudomyrmex gracilis) taken from Acacia hosts exhibited lower overall proteolytic activity than the mutualists. The proteases of this exploiter exhibited mainly elastase-like and to a lower degree chymotrypsin 1-like activity. We conclude that the mutualist ants possess specifically those proteases that are least sensitive to the PIs in their specific food source, whereas the congeneric exploiter ant appears partly, but not completely, adapted to consume Acacia FBs. By contrast, any consumption of the FBs by nonadapted exploiters would effectively inhibit their digestive capacities. We suggest that the term 'exclusive rewards' can be used to describe situations similar to the one that has evolved in myrmecophytic Acacia species, which reward mutualists with FBs but safeguard the reward from exploitation by generalists by making the FBs difficult for the nonadapted consumer to use.

  4. Protective Effect of Met12, a Small Peptide Inhibitor of Fas, on the Retinal Pigment Epithelium and Photoreceptor After Sodium Iodate Injury

    PubMed Central

    Xiao, Jianhui; Yao, Jingyu; Jia, Lin; Lin, Chengmao; Zacks, David N.

    2017-01-01

    Purpose A major problem in macular degeneration is the inability to reduce RPE and photoreceptor death. These cells die by necroptosis and apoptosis, respectively, but the upstream activator(s) of these death pathways is unknown. In this study, we use the sodium iodate (NaIO3) model of oxidative stress to test the hypothesis that activation of the Fas receptor contributes to the death of the RPE and photoreceptors. Methods Sodium iodate was injected in Brown-Norway rats via femoral vein injection. Both in vivo (fundus photography, optical coherence tomography, and fluorescein angiography) and ex vivo (histology, immunohistochemistry, Western blot, and RT-PCR) analyses of the RPE and retina were conducted at baseline, as well as at various times post NaIO3 injection. The ability of intravitreal injection of Met12, a small peptide inhibitor of the Fas receptor, to prevent RPE and photoreceptor cell death was assessed. Results Injection of NaIO3 led to Fas-mediated activation of both necroptosis and apoptosis in the RPE and photoreceptors, respectively. This was accompanied by a significant increase in the number of microglia/macrophages in the outer retina. Met12 significantly reduced the activation of the Fas-mediated death pathways, resulting in reduced RPE and photoreceptor death and a decreased immune response. Conclusions Our results demonstrate that NaIO3 activates Fas-mediated cell death, both in the RPE and photoreceptor, and that a small peptide antagonist of the Fas receptor, Met12, significantly reduces the extent of this cell death. These findings suggest a role for Fas inhibition to protect the RPE and photoreceptors from death due to oxidative stress. PMID:28346613

  5. Specific induction of the 70-kD heat stress proteins by the tyrosine kinase inhibitor herbimycin-A protects rat neonatal cardiomyocytes. A new pharmacological route to stress protein expression?

    PubMed Central

    Morris, S D; Cumming, D V; Latchman, D S; Yellon, D M

    1996-01-01

    Heat shock protein (hsp) induction by stressful stimuli such as heat and ischemia is known to protect cardiac cells from severe stress. The ability to induce hsp's in the heart directly by "nonstressful" means would potentially have important clinical implications. In noncardiac cells, the tyrosine kinase inhibitor herbimycin-A has been shown to induce the 72-kD hsp. We therefore examined whether herbimycin-A and another tyrosine kinase inhibitor, genistein, could induce 70-kD hsp's in primary cultures of rat neonatal cardiomyocytes, and whether these treatments protect against severe stress. Primary cardiomyocytes were incubated with herbimycin-A or genistein. hsp induction was measured 16-20 h later by Western blotting. Cell survival after subsequent lethal heat stress or simulated ischemia was assessed using trypan blue exclusion and released lactate dehydrogenase activity. Our results indicate that, in cardiac cells, herbimycin-A induces 70-kD hsp's but not hsp90, -60, -25, or glucose-regulated protein 78, whereas genistein has no effect on hsp's. Moreover, hsp induction correlated with the ability of herbimycin-A to protect cells against severe stress, whereas genistein has no protective effects. This suggests that herbimycin-A may induce 70-kD hsp's via a tyrosine kinase-independent mechanism. These results indicate the possibility of a pharmacological approach to HSP70 induction and cardiac protection, which may ultimately be of clinical relevance. PMID:8609226

  6. Effect of lactate-buffered peritoneal dialysis fluids on human peritoneal mesothelial cell interleukin-6 and prostaglandin synthesis.

    PubMed

    Witowski, J; Topley, N; Jörres, A; Liberek, T; Coles, G A; Williams, J D

    1995-01-01

    The present study focused on the evaluation of constitutive and cytokine-stimulated human peritoneal mesothelial cell (HPMC) IL-6 and 6-keto-PGF1 alpha release following pre-exposure to peritoneal dialysis fluid (PDF). Exposure of HPMC to PDF pH 5.2 resulted in a time-dependent increase in cell cytotoxicity [as assessed by lactate dehydrogenase (LDH) release] and concomitant inhibition of constitutive and IL-1 beta stimulated IL-6 and 6-keto-PGF1 alpha synthesis. After 15 minutes of exposure to PDF constitutive and IL-1 beta stimulated IL-6 release were reduced by 32.0 +/- 9.7% and 76.0 +/- 7.4% (N = 6, P < 0.046 and P < 0.027, respectively). PCR amplification of reverse transcribed mRNA from HPMC pre-exposed to PDF pH 5.2 demonstrated suppression of IL-1 beta stimulated IL-6 and cyclooxygenase (Cox-1 and Cox-2) transcripts. In order to mimic the dialysis cycle in vivo, an in vitro dialysis system was established. HPMC were exposed first to control medium, PDF pH 5.2 or PDF 7.3 for 15 minutes and then sequentially to pooled spent peritoneal dialysis effluent for up to four hours. The cells were subsequently allowed to recover in control medium for 12 hours in the presence or absence of IL-1 beta or TNF-alpha (both at 1000 pg/ml). There was no evidence of significant cell toxicity as assessed by LDH release during either the 'in vitro dialysis' or 'recovery' phases. Under these conditions short term exposure to PDF pH 5.2 followed by 'in vitro dialysis' resulted in significant inhibition of cytokine stimulated IL-6 (69.6 +/- 18.2 vs. 96.7 +/- 27.9 pg/microgram, N = 13; P < 0.020 for IL-1 beta) and 6-keto-PGF1 alpha (197.5 +/- 89.2 vs. 289.6 +/- 114.5 pg/microgram, N = 13; P < 0.020 for IL-1 beta) and 6-keto-PGF1 alpha (197.5 +/- 89.2 vs. 289.6 +/- 114.5 pg/microgram, N = 13; P < 0.003) release when compared to cells incubated in control medium. Adjustment of the pH of PDF to 7.3 reversed its inhibitory effects. We conclude that short-term exposure to PDF pH 5

  7. Corrosion and protection of heterogeneous cast Al-Si (356) and Al-Si-Cu-Fe (380) alloys by chromate adn cerium inhibitors

    NASA Astrophysics Data System (ADS)

    Jain, Syadwad

    In this study, the localized corrosion and conversion coating on cast alloys 356 (Al-7.0Si-0.3Mg) and 380 (Al-8.5Si-3.5Cu-1.6Fe) were characterized. The intermetallic phases presence in the permanent mold cast alloy 356 are primary-Si, Al5FeSi, Al8Si6Mg3Fe and Mg2Si. The die cast alloy 380 is rich in Cu and Fe elements. These alloying elements result in formation of the intermetallic phases Al 5FeSi, Al2Cu and Al(FeCuCr) along with primary-Si. The Cu- and Fe-rich IMPS are cathodic with respect to the matrix phase and strongly govern the corrosion behavior of the two cast alloys in an aggressive environment due to formation of local electrochemical cell in their vicinity. Results have shown that corrosion behavior of permanent mould cast alloy 356 is significantly better than the die cast aluminum alloy 380, primarily due to high content of Cu- and Fe-rich phases such as Al2Cu and Al 5FeSi in the latter. The IMPS also alter the protection mechanism of the cast alloys in the presence of inhibitors in an environment. The presence of chromate in the solution results in reduced cathodic activity on all the phases. Chromate provides some anodic inhibition by increasing pitting potentials and altering corrosion potentials for the phases. Results have shown that performance of CCC was much better on 356 than on 380, primarily due to inhomogeneous and incomplete coating deposition on Cu- and Fe- phases present in alloy 380. XPS and Raman were used to characterize coating deposition on intermetallics. Results show evidence of cyanide complex formation on the intermetallic phases. The presence of this complex is speculated to locally suppress CCC formation. Formation and breakdown of cerium conversion coatings on 356 and 380 was also analyzed. Results showed that deposition of cerium hydroxide started with heavy precipitation on intermetallic particles with the coatings growing outwards onto the matrix. Electrochemical analysis of synthesized intermetallics compounds in the

  8. Interphase fish analysis of cell cycle genes in asbestos-treated human mesothelial cells (HMC), SV40-transformed HMC (MeT-5A) and mesothelioma cells (COLO).

    PubMed

    Dopp, Elke; Poser, Ina; Papp, Thilo

    2002-01-01

    The epidemiologic association between asbestos exposure and human malignant mesothelioma is well established. However, the molecular mechanisms linking asbestos exposure of humans and the subsequent mesothelioma formation is not well understood. The most frequent genetic changes found so far in human malignant mesothelioma (HMM) are deletions and point mutations in the tumor suppressor genes p16INK4a and NF2. Whereas homozygous deletions appear to be the predominant mechanism leading to p16/CDKN2A inactivation, inactivating point mutations coupled with allelic loss mainly occur at the NF2 locus. In the present study, asbestos-treated human mesothelial cells (HMC), SV40-transformed human mesothelial cells (MeT-5A) and a human mesothelioma cell line (COLO) were investigated for genetic changes of cell cycle genes (cyclin D1, p16INK4a, RB1, CDK2) using multicolor fluorescence in situ hybridization (mFISH) in interphase cells. The results show that cyclin D1 is unaffected in all investigated cells. The p16INK4a gene locus was shown to be mutated in COLO cells but not in HMC. After labeling of CDK2 and RB1, hemizygous loss of one allele of each gene was observed in asbestos-treated HMC whereas gene amplification of these genes was detectable in MeT-5A and COLO cells. Our data indicate that disarrangement of the RB1 dependent pathway seems to be involved in mesothelioma formation.

  9. Evaluation of the oxidation of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) to toxic pyridinium cations by monoamine oxidase (MAO) enzymes and its use to search for new MAO inhibitors and protective agents.

    PubMed

    Herraiz, Tomás

    2012-12-01

    Monoamine oxidase (MAO) enzymes catalyze the oxidative deamination of amines and neurotransmitters and inhibitors of MAO are useful as neuroprotectants. This work evaluates the human MAO-catalyzed oxidation of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP), a dopaminergic neurotoxin, to the directly-acting neurotoxic metabolites, 1-methyl-4-phenyl-2,3-dihydropyridinium (MPDP(+)) and 1-methyl-4-phenylpyridinium (MPP(+)) measured by High-Performance Liquid Chromatography (HPLC), and this approach is subsequently used as a new method for screening of MAO inhibitors and protective agents. Oxidation of MPTP by human MAO-B was more efficient than by MAO-A. R-Deprenyl, a known neuroprotectant, norharman (β-carboline), 5-nitroindazole and menadione (vitamin K3) inhibited MAO-B and reduced the formation of toxic pyridinium cations. Clorgyline and the β-carbolines, harman and norharman, inhibited the oxidation of MPTP by MAO-A. Cigarette smoke, as well as the naturally occurring β-carbolines (norharman and harman) isolated from smoke and coffee inhibited the oxidation of MPTP by MAO-B and/or MAO-A, suggesting protective effects against MPTP. The results show the suitability of the approach used to search for new MAO inhibitors with eventual neuroprotective activity.

  10. Heat shock protein 72 enhances autophagy as a protective mechanism in lipopolysaccharide-induced peritonitis in rats.

    PubMed

    Li, Shu; Zhou, Yi; Fan, Jinjin; Cao, Shirong; Cao, Tao; Huang, Fengxian; Zhuang, Shougang; Wang, Yihan; Yu, Xueqing; Mao, Haiping

    2011-12-01

    Peritoneal dialysis-related peritonitis causes the denudation of mesothelial cells and, ultimately, membrane integrity alterations and peritoneal dysfunction. Because heat shock protein 72 (HSP72) confers protection against apoptosis and because autophagy mediates survival in response to cellular stresses, we examined whether autophagy contributes to HSP72-mediated cytoprotection in lipopolysaccharide (LPS)-induced peritonitis. Exposure of cultured peritoneal mesothelial cells to LPS resulted first in autophagy and later, apoptosis. Inhibition of autophagy by 3-methyladenine or Beclin-1 small-interfering RNA sensitized cells to apoptosis and abolished the antiapoptotic effect of HSP72, suggesting that autophagy activation acts as a prosurvival mechanism. Overexpression of HSP72 augmented autophagy through c-Jun N-terminal kinase (JNK) phosphorylation and Beclin-1 up-regulation. Suppression of JNK activity reversed HSP72-mediated Beclin-1 up-regulation and autophagy, indicating that HSP72-mediated autophagy is JNK dependent. In a rat model of LPS-associated peritonitis, autophagy occurred before apoptosis in peritoneum. Up-regulation of HSP72 by geranylgeranylacetone increased autophagy, inhibited apoptosis, and attenuated peritoneal injury, and these effects were blunted by down-regulation of HSP72 with quercetin. Additionally, blocking autophagy by chloroquine promoted apoptosis and aggravated LPS-associated peritoneal dysfunction. Thus, HSP72 protects peritoneum from LPS-induced mesothelial cells injury, at least in part by enhancing JNK activation-dependent autophagy and inhibiting apoptosis. These findings imply that HSP72 induction might be a potential therapy for peritonitis.

  11. Corrosion inhibitors for solar heating and cooling systems

    NASA Technical Reports Server (NTRS)

    Humphries, T. S.

    1978-01-01

    Inhibitors which appeared promising in previous tests and additional inhibitors including several proprietary products were evaluated. Evaluation of the inhibitors was based on corrosion protection afforded an aluminum-mild steel-copper-stainless steel assembly in a hot corrosive water. Of the inhibitors tested two were found to be effective and show promise for protecting multimetallic solar heating systems.

  12. Protective effect of a protein kinase inhibitor on cellular injury induced by cephaloridine in the porcine kidney cell line LLC-PK(1).

    PubMed

    Kawai, Yoshiko; Kohda, Yuka; Kodawara, Takaaki; Gemba, Munekazu

    2005-08-01

    We investigated the effects of a protein kinase C inhibitor and a tyrosine kinase inhibitor on the cellular injury induced by cephaloridine in an established renal epithelial cell line, LLC-PK(1). Cephaloridine increased the leakage of lactate dehydrogenase (LDH) from LLC-PK(1) cells into the medium and also caused an increase in the level of lipid peroxide (index of oxidative stress) in the cells. Treatment of the cells with a hydroxyl radical scavenger, dimethylthiourea (DMTU), inhibited the increases in LDH leakage and lipid peroxidation in LLC-PK(1) cells exposed to cephaloridine. A protein kinase C inhibitor, H-7, and tyrosine kinase inhibitors, genistein and lavendustinA, inhibited the increases in LDH leakage and lipid peroxidation in LLC-PK(1) cells exposed to cephaloridine. These results suggest that a signaling pathway which involves protein kinase C and tyrosine kinase plays a role in the generation of reactive oxygen species in LLC-PK(1) cells damaged by cephaloridine.

  13. Effects of Potent Inhibitors of the Retinoid Cycle on Visual Function and Photoreceptor Protection from Light Damage in MiceS

    PubMed Central

    Maeda, Akiko; Maeda, Tadao; Golczak, Marcin; Imanishi, Yoshikazu; Leahy, Patrick; Kubota, Ryo; Palczewski, Krzysztof

    2014-01-01

    Regeneration of the chromophore 11-cis-retinal is essential for the generation of light-sensitive visual pigments in the vertebrate retina. A deficiency in 11-cis-retinal production leads to congenital blindness in humans; however, a buildup of the photoisomerized chromophore can also be detrimental. Such is the case when the photoisomerized all-trans-retinal is produced but cannot be efficiently cleared from the internal membrane of the outer segment discs. Sustained increase of all-trans-retinal can lead to the formation of toxic condensation products in the eye. Thus, there is a need for potent, selective inhibitors that can regulate the flux of retinoids through the metabolism pathway termed the visual (retinoid) cycle. Here we systematically study the effects of the most potent inhibitor of this cycle, retinylamine (Ret-NH2), on visual function in mice. Prolonged, sustainable, but reversible suppression of the visual function was observed by Ret-NH2 as a result of its storage in a prodrug form, N-retinylamides. Direct comparison of other inhibitors such as fenretinide and 13-cis-retinoic acid showed multiple advantages of Ret-NH2 and its amides, including a higher potency, specificity, and lower transcription activation. Our results also revealed that mice treated with Ret-NH2 were completely resistant to the light-induced retina damage. As an experimental tool, Ret-NH2 allows the replacement of the native chromophore with synthetic analogs in wild-type mice to better understand the function of the chromophore in the activation of rhodopsin and its metabolism through the retinoid cycle. PMID:16837623

  14. DA-1229, a dipeptidyl peptidase IV inhibitor, protects against renal injury by preventing podocyte damage in an animal model of progressive renal injury.

    PubMed

    Eun Lee, Jee; Kim, Jung Eun; Lee, Mi Hwa; Song, Hye Kyoung; Ghee, Jung Yeon; Kang, Young Sun; Min, Hye Sook; Kim, Hyun Wook; Cha, Jin Joo; Han, Jee Young; Han, Sang Youb; Cha, Dae Ryong

    2016-05-01

    Although dipeptidyl peptidase IV (DPPIV) inhibitors are known to have renoprotective effects, the mechanism underlying these effects has remained elusive. Here we investigated the effects of DA-1229, a novel DPPIV inhibitor, in two animal models of renal injury including db/db mice and the adriamycin nephropathy rodent model of chronic renal disease characterized by podocyte injury. For both models, DA-1229 was administered at 300 mg/kg/day. DPPIV activity in the kidney was significantly higher in diabetic mice compared with their nondiabetic controls. Although DA-1229 did not affect glycemic control or insulin resistance, DA-1229 did improve lipid profiles, albuminuria and renal fibrosis. Moreover, DA-1229 treatment resulted in decreased urinary excretion of nephrin, decreased circulating and kidney DPPIV activity, and decreased macrophage infiltration in the kidney. In adriamycin-treated mice, DPPIV activity in the kidney and urinary nephrin loss were both increased, whereas glucagon-like peptide-1 concentrations were unchanged. Moreover, DA-1229 treatment significantly improved proteinuria, renal fibrosis and inflammation associated with decreased urinary nephrin loss, and kidney DPP4 activity. In cultured podocytes, DA-1229 restored the high glucose/angiotensin II-induced increase of DPPIV activity and preserved the nephrin levels in podocytes. These findings suggest that activation of DPPIV in the kidney has a role in the progression of renal disease, and that DA-1229 may exert its renoprotective effects by preventing podocyte injury.

  15. Anti-Inflammatory Effects and Joint Protection in Collagen-Induced Arthritis after Treatment with IQ-1S, a Selective c-Jun N-Terminal Kinase Inhibitor.

    PubMed

    Schepetkin, Igor A; Kirpotina, Liliya N; Hammaker, Deepa; Kochetkova, Irina; Khlebnikov, Andrei I; Lyakhov, Sergey A; Firestein, Gary S; Quinn, Mark T

    2015-06-01

    c-Jun N-terminal kinases (JNKs) participate in many physiologic and pathologic processes, including inflammatory diseases. We recently synthesized the sodium salt of IQ-1S (11H-indeno[1,2-b]quinoxalin-11-one oxime) and demonstrated that it is a high-affinity JNK inhibitor and inhibits murine delayed-type hypersensitivity. Here we show that IQ-1S is highly specific for JNK and that its neutral form is the most abundant species at physiologic pH. Molecular docking of the IQ-1S syn isomer into the JNK1 binding site gave the best pose, which corresponded to the position of cocrystallized JNK inhibitor SP600125 (1,9-pyrazoloanthrone). Evaluation of the therapeutic potential of IQ-1S showed that it inhibited matrix metalloproteinase 1 and 3 gene expression induced by interleukin-1β in human fibroblast-like synoviocytes and significantly attenuated development of murine collagen-induced arthritis (CIA). Treatment with IQ-1S either before or after induction of CIA resulted in decreased clinical scores, and joint sections from IQ-1S-treated CIA mice exhibited only mild signs of inflammation and minimal cartilage loss compared with those from control mice. Collagen II-specific antibody responses were also reduced by IQ-1S treatment. By contrast, the inactive ketone derivative 11H-indeno[1,2-b]quinoxalin-11-one had no effect on CIA clinical scores or collagen II-specific antibody titers. IQ-1S treatment also suppressed proinflammatory cytokine and chemokine levels in joints and lymph node cells. Finally, treatment with IQ-1S increased the number of Foxp3(+)CD4(+)CD25(+) regulatory T cells in lymph nodes. Thus, IQ-1S can reduce inflammation and cartilage loss associated with CIA and can serve as a small-molecule modulator for mechanistic studies of JNK function in rheumatoid arthritis.

  16. The Culicoides sonorensis inhibitor of apoptosis 1 protein protects mammalian cells from apoptosis induced by infection with African horse sickness virus and bluetongue virus.

    PubMed

    Vermaak, Elaine; Maree, Francois F; Theron, Jacques

    2017-03-04

    African horse sickness virus (AHSV) and bluetongue virus (BTV) are arboviruses of the genus Orbivirus that are transmitted to their vertebrate hosts by Culicoides biting midges. These orbiviruses exhibit lytic infection (apoptosis) in mammalian cells, but cause persistent infection with no cytopathic effects in Culicoides sonorensis cells. Although regulation of apoptosis could thus be integral for establishing persistent virus infection in midge cells, nothing is known about the presence and function of apoptosis pathways in Culicoides midges and their derived cell lines. Here, we report the cloning and functional characterization of an inhibitor of apoptosis protein (IAP), designated CsIAP1, from C. sonorensis cells. The CsIAP1 protein contains two baculoviral IAP repeat (BIR) domains and a RING domain. Silencing of the Cs iap1 gene in C. sonorensis cells caused apoptosis, indicating that CsIAP1 plays a role in cell survival. Stable expression of the CsIAP1 protein in BSR mammalian cells suppressed apoptosis induced by AHSV-4 and BTV-10 infection, and biochemical data indicated that CsIAP1 is an inhibitor of mammalian caspase-9, an initiator caspase in the intrinsic apoptotic pathway. Mutagenesis studies indicated that the BIR2 and RING domains are required for the anti-apoptotic activity of CsIAP1. The results suggest that the mechanism by which CsIAP1 suppresses apoptosis in insect cells may involve inhibition of a Culicoides caspase-9 homologue through a mechanism that requires both the BIR2 and RING domains. This study provides the first evidence that the CsIAP1 protein is a key negative regulator of apoptosis in C. sonorensis cells.

  17. Combining the rapid MTT formazan exocytosis assay and the MC65 protection assay led to the discovery of carbazole analogs as small molecule inhibitors of Abeta oligomer-induced cytotoxicity.

    PubMed

    Hong, Hyun-Seok; Maezawa, Izumi; Yao, Nianhuan; Xu, Bailing; Diaz-Avalos, Ruben; Rana, Sandeep; Hua, Duy H; Cheng, R Holland; Lam, Kit S; Jin, Lee-Way

    2007-01-26

    The discovery of small molecule inhibitors of cytotoxicity induced by amyloid-beta (Abeta) oligomers, either applied extracellularly or accumulated intraneuronally, is an important goal of drug development for Alzheimer's disease (AD), but has been limited by the lack of efficient screening methods. Here we describe our approach using two cell-based methods. The first method takes advantage of the unique ability of extracellularly applied Abeta oligomers to rapidly induce the exocytosis of formazan formed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT). We employed a short protocol to quantify this toxicity, and quickly identified two novel inhibitors, code-named CP2 and A5, from two compound libraries. A second independent screen of the same libraries using our previously published MC65 protection assay, which identifies inhibitors of toxicity related to intracellular Abeta oligomers, also selected the same two leads, suggesting that both assays select for the same anti-Abeta oligomer properties displayed by these compounds. We further demonstrated that A5 attenuated the progressive aggregation of existing Abeta oligomers, reduced the level of intracellular Abeta oligomers, and prevented the Abeta oligomer-induced death of primary cortical neurons, effects similar to those demonstrated by CP2. Our results suggest that, when combined, the two methods would generate fewer false results and give a high likelihood of identifying leads that show promises in ameliorating Abeta oligomer-induced toxicities within both intraneuronal and extracellular sites. Both assays are simple, suitable for rapid screening of a large number of medicinal libraries, and amenable for automation.

  18. Determination of the Minimum Use Level of Fuel System Icing Inhibitor (FSII) in JP-8 That Will Provide Adquate Icing Inhibition and Biostatic Protection for Air Force Aircraft

    DTIC Science & Technology

    2013-12-01

    additive in JP-8, is used to prevent solidification of free water in the fuel and to provide protection against microbial growth in fuel systems. The...A/C Use Limit, Icing Inhibition, Bacteria, Microbial Contamination, B-52, Icing Rig, Aqueous Solution, Partitioning Coefficient, Solubility, Fuel... cellulose filter used in the fuel strainer of the B-52 (nominal openings of ~ 40-50 µm) and a 50-mesh metal screen (320 µm square openings with 200 µm wire

  19. The nonnucleoside reverse transcription inhibitor MIV-160 delivered from an intravaginal ring, but not from a carrageenan gel, protects against simian/human immunodeficiency virus-RT Infection.

    PubMed

    Aravantinou, Meropi; Singer, Rachel; Derby, Nina; Calenda, Giulia; Mawson, Paul; Abraham, Ciby J; Menon, Radhika; Seidor, Samantha; Goldman, Daniel; Kenney, Jessica; Villegas, Guillermo; Gettie, Agegnehu; Blanchard, James; Lifson, Jeffrey D; Piatak, Michael; Fernández-Romero, José A; Zydowsky, Thomas M; Teleshova, Natalia; Robbiani, Melissa

    2012-11-01

    We previously showed that a carrageenan (CG) gel containing 50 μM MIV-150 (MIV-150/CG) reduced vaginal simian/human immunodeficiency virus (SHIV)-RT infection of macaques (56%, p>0.05) when administered daily for 2 weeks with the last dose given 8 h before challenge. Additionally, when 100 mg of MIV-150 was loaded into an intravaginal ring (IVR) inserted 24 h before challenge and removed 2 weeks after challenge, >80% protection was observed (p<0.03). MIV-160 is a related NNRTI with a similar IC(50), greater aqueous solubility, and a shorter synthesis. To objectively compare MIV-160 with MIV-150, herein we evaluated the antiviral effects of unformulated MIV-160 in vitro as well as the in vivo protection afforded by MIV-160 delivered in CG (MIV-160/CG gel) and in an IVR under regimens used with MIV-150 in earlier studies. Like MIV-150, MIV-160 exhibited potent antiviral activity against SHIV-RT in macaque vaginal explants. However, formulated MIV-160 exhibited divergent effects in vivo. The MIV-160/CG gel offered no protection compared to CG alone, whereas the MIV-160 IVRs protected significantly. Importantly, the results of in vitro release studies of the MIV-160/CG gel and the MIV-160 IVR suggested that in vivo efficacy paralleled the amount of MIV-160 released in vitro. Hundreds of micrograms of MIV-160 were released daily from IVRs while undetectable amounts of MIV-160 were released from the CG gel. Our findings highlight the importance of testing different modalities of microbicide delivery to identify the optimal formulation for efficacy in vivo.

  20. A gene for plant protection: expression of a bean polygalacturonase inhibitor in tobacco confers a strong resistance against Rhizoctonia solani and two oomycetes.

    PubMed

    Borras-Hidalgo, Orlando; Caprari, Claudio; Hernandez-Estevez, Ingrid; Lorenzo, Giulia De; Cervone, Felice

    2012-01-01

    We have tested whether a gene encoding a polygalacturonase-inhibiting protein (PGIP) protects tobacco against a fungal pathogen (Rhizoctonia solani) and two oomycetes (Phytophthora parasitica var. nicotianae and Peronospora hyoscyami f. sp. tabacina). The trials were performed in greenhouse conditions for R. solani and P. parasitica and in the field for P. hyoscyami. Our results show that expression of PGIP is a powerful way of engineering a broad-spectrum disease resistance.

  1. Discovery of a benzofuran derivative (MBPTA) as a novel ROCK inhibitor that protects against MPP⁺-induced oxidative stress and cell death in SH-SY5Y cells.

    PubMed

    Chong, Cheong-Meng; Shen, Mingyun; Zhou, Zhong-Yan; Pan, Peichen; Hoi, Pui-Man; Li, Shang; Liang, Wang; Ai, Nana; Zhang, Lun-Qing; Li, Cheuk-Wing; Yu, Huidong; Hou, Tingjun; Lee, Simon Ming-Yuen

    2014-09-01

    Parkinson disease (PD) is a neurodegenerative disease with multifactorial etiopathogenesis. The discovery of drug candidates that act on new targets of PD is required to address the varied pathological aspects and modify the disease process. In this study, a small compound, 2-(5-methyl-1-benzofuran-3-yl)-N-(5-propylsulfanyl-1,3,4-thiadiazol-2-yl) acetamide (MBPTA) was identified as a novel Rho-associated protein kinase inhibitor with significant protective effects against 1-methyl-4-phenylpyridinium ion (MPP(+))-induced damage in SH-SY5Y neuroblastoma cells. Further investigation showed that pretreatment of SH-SY5Y cells with MBPTA significantly suppressed MPP(+)-induced cell death by restoring abnormal changes in nuclear morphology, mitochondrial membrane potential, and numerous apoptotic regulators. MBPTA was able to inhibit MPP(+)-induced reactive oxygen species (ROS)/NO generation, overexpression of inducible NO synthase, and activation of NF-κB, indicating the critical role of MBPTA in regulating ROS/NO-mediated cell death. Furthermore, MBPTA was shown to activate PI3K/Akt survival signaling, and its cytoprotective effect was abolished by PI3K and Akt inhibitors. The structural comparison of a series of MBPTA analogs revealed that the benzofuran moiety probably plays a crucial role in the anti-oxidative stress action. Taken together, these results suggest that MBPTA protects against MPP(+)-induced apoptosis in a neuronal cell line through inhibition of ROS/NO generation and activation of PI3K/Akt signaling.

  2. The predominant protective effect of tianeptine over other antidepressants in models of neuronal apoptosis: the effect blocked by inhibitors of MAPK/ERK1/2 and PI3-K/Akt pathways.

    PubMed

    Jantas, D; Krawczyk, S; Lason, W

    2014-02-01

    Tianeptine (Tian) possesses neuroprotective potential, however, little is known about the effect of this drug in models of neuronal apoptosis. In the present study, we aimed (1) to compare the neuroprotective capacities of some antidepressants (ADs) in the models of staurosporine (St)- and doxorubicin (Dox)-evoked cell death, activating the intracellular and the extracellular apoptotic pathway, respectively; (2) to identify the Tian-modulated steps underlying its neuroprotective action; (3) to test the effect of various ADs against Dox-evoked cell damage in glia cells. Primary neuronal and glia cell cultures and retinoic acid-differentiated human neuroblastoma SH-SY5Y (RA-SH-SY5Y) cells were co-treated with imipramine, fluoxetine, citalopram, reboxetine, mirtazapine or Tian and St or Dox. The data showed the predominant neuroprotective effect of Tian over other tested ADs against St- and Dox-induced cell damage in primary neurons and in RA-SH-SY5Y cells. This effect was shown to be caspase-3-independent but connected with attenuation of DNA fragmentation. Moreover, neuroprotection elicited by Tian was blocked by pharmacological inhibitors of MAPK/ERK1/2 and PI3-K/Akt signaling pathways as well by inhibitor of necroptosis, necrostatin-1. Interestingly, the protective effects of all tested ADs were demonstrated in primary glia cells against the Dox-evoked cell damage. The obtained data suggests the glial cells as a common target for protective action of various ADs whereas in relation to neuronal cells only Tian possesses such properties, at least against St- and Dox-induced cell damage. Moreover, this neuroprotective effect of Tian is caspase-3-independent and engages the regulation of survival pathways (MAPK/ERK1/2 and PI3-K/Akt).

  3. A possible involvement of Nrf2-mediated heme oxygenase-1 up-regulation in protective effect of the proton pump inhibitor pantoprazole against indomethacin-induced gastric damage in rats

    PubMed Central

    2012-01-01

    Background Proton pump is an integral membrane protein that is ubiquitous ATP binding cassette (ABC) involved in many transport processes in all living organisms, among which a specialized form of pump, so called p-type proton pump, exists in the parietal cells of stomach. Though proton pump inhibitors (PPIs) are frequently prescribed to prevent nonsteroidal anti-inflammatory drugs (NSAIDs)-induced gastric damage, the acid suppressive actions do not suffice to explain. Methods In order to document the effects of pantoprazole, one of PPIs, on the NSAIDs-induced gastric damage, in vitro and in vivo studies were performed. Immunocytochemistry, Western blot analysis, electrophoretic mobility shift assay and RT-PCR were conducted to evaluate the induction of heme oxygenase-1 (HO-1) through Nrf2 activation in normal gastric mucosal RGM-1 cells or in vivo stomach tissues from rats treated with indomethacin and/or pantoprazole. Results Pantoprazole activated Nrf2 through inactivation of Keap1, after which the expression of HO-1 was significantly increased in a dose-dependent manner in RGM-1 cells. Increased ARE-DNA binding activity was observed maximally at 1 h with 300 μM of pantoprazole. The expression of HO-1 induced by pantoprazole was significantly associated with the increased in vitro tube formation (P < 0.05) and angiogenic factors including VEGF, bFGF, and HIF-1α. Indomethacin markedly increased the expressions of TNF-α, IL-1ß, IL-8, NOX-1, ICAM-1 and VCAM, whereas pantoprazole significantly decreased the expressions of indomethacin-induced these inflammatory mediators in accord with pantoprazole-induced HO-1 (P < 0.05) as documented with HO-1 inhibitor. In vivo model of indomethacin-induced gastric damage could validate in vitro-drawn results that pantoprazole remarkably protected against indomethacin-induced gastric damage, in which zinc protoporphyrin (5 mg/kg, ip) significantly abolished the protective efficacy of pantoprazole. Conclusion These results

  4. Differential contributions of STAT5A and STAT5B to stress protection and tyrosine kinase inhibitor resistance of chronic myeloid leukemia stem/progenitor cells.

    PubMed

    Casetti, Luana; Martin-Lannerée, Séverine; Najjar, Imen; Plo, Isabelle; Augé, Sylvie; Roy, Lydia; Chomel, Jean-Claude; Lauret, Evelyne; Turhan, Ali G; Dusanter-Fourt, Isabelle

    2013-04-01

    STAT5 fulfills essential roles in hematopoietic stem cell (HSC) self-renewal and chronic myeloid leukemia (CML), a prototypical stem cell malignancy. However, the specific contributions of the two related genes STAT5A and STAT5B have not been determined. In this study, we used a RNAi-based strategy to establish participation of these genes to CML disease and persistence following targeted therapy. We showed that STAT5A/STAT5B double-knockdown triggers CML cell apoptosis and suppresses both normal and CML HSC long-term clonogenic potential. STAT5A and STAT5B exhibited similar prosurvival activity, but STAT5A attenuation alone was ineffective at impairing growth of normal and CML CD34(+) cells isolated at diagnosis. In contrast, STAT5A attenuation was sufficient to enhance basal oxidative stress and DNA damage of normal CD34(+) and CML cells. Furthermore, it weakened the ability to manage exogenous oxidative stress, increased p53 (TRP53)/CHK-2 (CHEK2) stress pathway activation, and enhanced prolyl hydroxylase domain (PHD)-3 (EGLN3) mRNA expression. Only STAT5A and its transactivation domain-deficient mutant STAT5AΔ749 specifically rescued these activities. STAT5A attenuation was also active at inhibiting growth of CML CD34(+) cells from patients with acquired resistance to imatinib. Our findings show that STAT5A has a selective role in contributing to stress resistance through unconventional mechanisms, offering new opportunities to eradicate the most primitive and tyrosine kinase inhibitor-resistant CML cells with an additional potential to eradicate persistent stem cell populations.

  5. In vitro biodegradation of chrysotile fibres by alveolar macrophages and mesothelial cells in culture: comparison with a pH effect.

    PubMed

    Jaurand, M C; Gaudichet, A; Halpern, S; Bignon, J

    1984-08-01

    The modification of the chemistry of asbestos chrysotile fibres (Mg3(Si2O5)(OH)4) after their ingestion by cultured cells has been studied. Two types of cells involved in asbestos related pulmonary disease were used, rabbit alveolar macrophages (AM), recovered by bronchoalveolar lavage, and pleural mesothelial cells (PMC) obtained from the rat parietal pleura. Chemical characterisation of intracellular fibres was performed on unstained ultrathin sections by electron probe microanalysis. The results showed a progressive leaching of Mg, characterised by a time dependent decrease of Mg/Si. AM were more efficient than PMC at leaching intracellular chrysotile fibres since it took longer to obtain the same proportion of leached fibres with PMC than with AM. As in vitro Mg-leaching can be obtained by acid treatment, chrysotile fibres were incubated, either untreated or pretreated with cell membranes, at pH 4 or 7 for various times. The data show that the kinetic of leaching by AM was comparable with leaching at pH 4. The leaching by PMC was of the same order as leaching at pH 7. When membranes were adsorbed on to the fibres, a delayed leaching was observed. The results indicate that the solubilisation of chrysotile by AM could be an intraphagolysosomal event due to a pH effect. With PMC, however, it is not possible to draw this conclusion since nothing is known about the intracellular pH.

  6. The phosphodiesterase-4 inhibitor rolipram protects from ischemic stroke in mice by reducing blood-brain-barrier damage, inflammation and thrombosis.

    PubMed

    Kraft, Peter; Schwarz, Tobias; Göb, Eva; Heydenreich, Nadine; Brede, Marc; Meuth, Sven G; Kleinschnitz, Christoph

    2013-09-01

    Blood-brain-barrier (BBB) disruption, inflammation and thrombosis are important steps in the pathophysiology of acute ischemic stroke but are still inaccessible to therapeutic interventions. Rolipram specifically inhibits the enzyme phosphodiesterase (PDE) 4 thereby preventing the inactivation of the intracellular second messenger cyclic adenosine monophosphate (cAMP). Rolipram has been shown to relief inflammation and BBB damage in a variety of neurological disorders. We investigated the therapeutic potential of rolipram in a model of brain ischemia/reperfusion injury in mice. Treatment with 10mg/kg rolipram, but not 2 mg/kg rolipram, 2 h after 60 min of transient middle cerebral artery occlusion (tMCAO) reduced infarct volumes by 50% and significantly improved clinical scores on day 1 compared with vehicle-treated controls. Rolipram maintained BBB function upon stroke as indicated by preserved expression of the tight junction proteins occludin and claudin-5. Accordingly, the formation of vascular brain edema was strongly attenuated in mice receiving rolipram. Moreover, rolipram reduced the invasion of neutrophils as well as the expression of the proinflammatory cytokines IL-1β and TNFα but increased the levels of TGFβ-1. Finally, rolipram exerted antithrombotic effects upon stroke and fewer neurons in the rolipram group underwent apoptosis. Rolipram is a multifaceted antiinflammatory and antithrombotic compound that protects from ischemic neurodegeneration in clinically meaningful settings.

  7. Screening of differentially expressed protein kinases in bone marrow endothelial cells and the protective effects of the p38a inhibitor SB203580 on bone marrow in liver fibrosis

    PubMed Central

    Gao, Bo; Sun, Wang; Meng, Xianzhi; Xue, Dongbo; Zhang, Weihui

    2016-01-01

    Hematological abnormalities are frequently observed in patients with liver cirrhosis (LC). A previous study demonstrated that the apoptosis and damage of endothelial cells could cause the hematological abnormalities in LC. Protein kinases are one of the most important factors that regulate cell behavior, and are potential therapeutic targets for the treatment of a number of diseases. In a previous study, whole genome profiling was used to identify differentially expressed genes in human bone marrow endothelial cells treated with serum from 26 patients with LC. From this data set, the present study identified 14 differentially expressed kinase genes in human bone marrow endothelial cells in LC from the microarray data, including p38a, AKT1 and PDK1. Pathway analysis revealed that these kinase genes were enriched in certain important LC-associated pathways (e.g. MAPK and WNT signaling pathway). Literature mining revealed that p38a was associated with bone marrow apoptosis; therefore, p38a and its inhibitor, SB203580, were selected as potential therapeutic targets in the present study. The results of hematoxylin-eosin and Masson's trichrome staining of livers from a rat model of liver fibrosis (LF) that underwent ligation of the bile duct demonstrated that SB203580 reduced the degree of LF. In addition, SB203580-treated rats with LF demonstrated a significantly higher number of platelets when compared with the untreated group. Terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) analysis indicated that apoptosis of bone marrow tissue in rats with LF was inhibited by SB203580. In addition, the results from the immunohistochemical analysis demonstrated that SB203580 reduced the expression of von Willebrand factor and caspase 3 in the bone marrow of rats with LF. In conclusion, the results from the present study indicate that the p38a kinase inhibitor, SB203580, may exhibit a protective effect on bone marrow tissues in rats with LF. This suggests that

  8. Angiogenesis Inhibitors

    MedlinePlus

    ... inhibitors: current strategies and future prospects. CA: A Cancer Journal for Clinicians 2010; 60(4):222–243. [PubMed Abstract] Chen HX, Cleck JN. Adverse effects of anticancer agents that target the VEGF pathway. Nature Reviews Clinical Oncology 2009; 6(8):465– ...

  9. Carboxylesterase inhibitors

    PubMed Central

    Hatfield, M. Jason; Potter, Philip M.

    2011-01-01

    Introduction Carboxylesterases play major roles in the hydrolysis of numerous therapeutically active compounds. This is, in part, due to the prevalence of the ester moiety in these small molecules. However, the impact these enzymes may play on drug stability and pharmacokinetics is rarely considered prior to molecule development. Therefore, the application of selective inhibitors of this class of proteins may have utility in modulating the metabolism, distribution and toxicity of agents that are subjected to enzyme hydrolysis. Areas covered This review details the development of all such compounds dating back to 1986, but principally focuses on the very recent identification of selective human carboxylesterases inhibitors. Expert opinion The implementation of carboxylesterase inhibitors may significantly revolutionize drug discovery. Such molecules may allow for improved efficacy of compounds inactivated by this class of enzymes and/or reduce the toxicity of agents that are activated by these proteins. Furthermore, since lack of carboxylesterase activity appears to have no obvious biological consequence, these compounds could be applied in combination with virtually any esterified drug. Therefore, inhibitors of these proteins may have utility in altering drug hydrolysis and distribution in vivo. The characteristics, chemical and biological properties, and potential uses of such agents, are discussed here. PMID:21609191

  10. AS-2, a novel inhibitor of p53-dependent apoptosis, prevents apoptotic mitochondrial dysfunction in a transcription-independent manner and protects mice from a lethal dose of ionizing radiation

    SciTech Connect

    Morita, Akinori; Ariyasu, Shinya; Wang, Bing; Asanuma, Tetsuo; Onoda, Takayoshi; Sawa, Akiko; Tanaka, Kaoru; Takahashi, Ippei; Togami, Shotaro; Nenoi, Mitsuru; Inaba, Toshiya; Aoki, Shin

    2014-08-08

    Highlights: • A bidentate HQ derivative, AS-2, suppresses p53-dependent apoptosis by DNA damage. • AS-2 does not significantly affect nuclear p53 response. • UV-excited blue emission of AS-2 clearly showed its extranuclear localization. • AS-2 prevents mitochondrial dysfunction despite the increase of mitochondrial p53. • AS-2 protects mice from a radiation dose that causes lethal hematopoietic syndrome. - Abstract: In a previous study, we reported that some tetradentate zinc(II) chelators inhibit p53 through the denaturation of its zinc-requiring structure but a chelator, Bispicen, a potent inhibitor of in vitro apoptosis, failed to show any efficient radioprotective effect against irradiated mice because the toxicity of the chelator to mice. The unsuitability of using tetradentate chelators as radioprotectors prompted us to undertake a more extensive search for p53-inhibiting agents that are weaker zinc(II) chelators and therefore less toxic. Here, we show that an 8-hydroxyquinoline (8HQ) derivative, AS-2, suppresses p53-dependent apoptosis through a transcription-independent mechanism. A mechanistic study using cells with different p53 characteristics revealed that the suppressive effect of AS-2 on apoptosis is specifically mediated through p53. In addition, AS-2 was less effective in preventing p53-mediated transcription-dependent events than pifithrin-μ (PFTμ), an inhibitor of transcription-independent apoptosis by p53. Fluorescence visualization of the extranuclear distribution of AS-2 also supports that it is ineffective on the transcription-dependent pathway. Further investigations revealed that AS-2 suppressed mitochondrial apoptotic events, such as the mitochondrial release of intermembrane proteins and the loss of mitochondrial membrane potential, although AS-2 resulted in an increase in the mitochondrial translocation of p53 as opposed to the decrease of cytosolic p53, and did not affect the apoptotic interaction of p53 with Bcl-2. AS-2 also

  11. Tumor Necrosis Factor Receptor-associated Protein 1 (TRAP1) Mutation and TRAP1 Inhibitor Gamitrinib-triphenylphosphonium (G-TPP) Induce a Forkhead Box O (FOXO)-dependent Cell Protective Signal from Mitochondria*

    PubMed Central

    Kim, Hyunjin; Yang, Jinsung; Kim, Min Ju; Choi, Sekyu; Chung, Ju-Ryung; Kim, Jong-Min; Yoo, Young Hyun; Chung, Jongkyeong; Koh, Hyongjong

    2016-01-01

    TRAP1 (tumor necrosis factor receptor-associated protein 1), a mitochondrial Hsp90 family chaperone, has been identified as a critical regulator of cell survival and bioenergetics in tumor cells. To discover novel signaling networks regulated by TRAP1, we generated Drosophila TRAP1 mutants. The mutants successfully developed into adults and produced fertile progeny, showing that TRAP1 is dispensable in development and reproduction. Surprisingly, mutation or knockdown of TRAP1 markedly enhanced Drosophila survival under oxidative stress. Moreover, TRAP1 mutation ameliorated mitochondrial dysfunction and dopaminergic (DA) neuron loss induced by deletion of a familial Parkinson disease gene PINK1 (Pten-induced kinase 1) in Drosophila. Gamitrinib-triphenylphosphonium, a mitochondria-targeted Hsp90 inhibitor that increases cell death in HeLa and MCF7 cells, consistently inhibited cell death induced by oxidative stress and mitochondrial dysfunction induced by PINK1 mutation in mouse embryonic fibroblast cells and DA cell models such as SH-SY5Y and SN4741 cells. Additionally, gamitrinib-triphenylphosphonium also suppressed the defective locomotive activity and DA neuron loss in Drosophila PINK1 null mutants. In further genetic analyses, we showed enhanced expression of Thor, a downstream target gene of transcription factor FOXO, in TRAP1 mutants. Furthermore, deletion of FOXO almost nullified the protective roles of TRAP1 mutation against oxidative stress and PINK1 mutation. These results strongly suggest that inhibition of the mitochondrial chaperone TRAP1 generates a retrograde cell protective signal from mitochondria to the nucleus in a FOXO-dependent manner. PMID:26631731

  12. Tumor Necrosis Factor Receptor-associated Protein 1 (TRAP1) Mutation and TRAP1 Inhibitor Gamitrinib-triphenylphosphonium (G-TPP) Induce a Forkhead Box O (FOXO)-dependent Cell Protective Signal from Mitochondria.

    PubMed

    Kim, Hyunjin; Yang, Jinsung; Kim, Min Ju; Choi, Sekyu; Chung, Ju-Ryung; Kim, Jong-Min; Yoo, Young Hyun; Chung, Jongkyeong; Koh, Hyongjong

    2016-01-22

    TRAP1 (tumor necrosis factor receptor-associated protein 1), a mitochondrial Hsp90 family chaperone, has been identified as a critical regulator of cell survival and bioenergetics in tumor cells. To discover novel signaling networks regulated by TRAP1, we generated Drosophila TRAP1 mutants. The mutants successfully developed into adults and produced fertile progeny, showing that TRAP1 is dispensable in development and reproduction. Surprisingly, mutation or knockdown of TRAP1 markedly enhanced Drosophila survival under oxidative stress. Moreover, TRAP1 mutation ameliorated mitochondrial dysfunction and dopaminergic (DA) neuron loss induced by deletion of a familial Parkinson disease gene PINK1 (Pten-induced kinase 1) in Drosophila. Gamitrinib-triphenylphosphonium, a mitochondria-targeted Hsp90 inhibitor that increases cell death in HeLa and MCF7 cells, consistently inhibited cell death induced by oxidative stress and mitochondrial dysfunction induced by PINK1 mutation in mouse embryonic fibroblast cells and DA cell models such as SH-SY5Y and SN4741 cells. Additionally, gamitrinib-triphenylphosphonium also suppressed the defective locomotive activity and DA neuron loss in Drosophila PINK1 null mutants. In further genetic analyses, we showed enhanced expression of Thor, a downstream target gene of transcription factor FOXO, in TRAP1 mutants. Furthermore, deletion of FOXO almost nullified the protective roles of TRAP1 mutation against oxidative stress and PINK1 mutation. These results strongly suggest that inhibition of the mitochondrial chaperone TRAP1 generates a retrograde cell protective signal from mitochondria to the nucleus in a FOXO-dependent manner.

  13. Genotoxicity of short single-wall and multi-wall carbon nanotubes in human bronchial epithelial and mesothelial cells in vitro.

    PubMed

    Lindberg, Hanna K; Falck, Ghita C-M; Singh, Rajinder; Suhonen, Satu; Järventaus, Hilkka; Vanhala, Esa; Catalán, Julia; Farmer, Peter B; Savolainen, Kai M; Norppa, Hannu

    2013-11-08

    Although some types of carbon nanotubes (CNTs) have been described to induce mesothelioma in rodents and genotoxic effects in various cell systems, there are few previous studies on the genotoxicity of CNTs in mesothelial cells. Here, we examined in vitro DNA damage induction by short multi-wall CNTs (MWCNTs; 10-30 nm × 1-2 μm) and single-wall CNTs (SWCNTs; >50% SWCNTs, ~40% other CNTs; <2 nm × 1-5 μm) in human mesothelial (MeT-5A) cells and bronchial epithelial (BEAS 2B) cells, using the single cell gel electrophoresis (comet) assay and the immunoslot blot assay for the detection of malondialdehyde (M1dG) DNA adducts. In BEAS 2B cells, we also studied the induction of micronuclei (MN) by the CNTs using the cytokinesis-block method. The cells were exposed to the CNTs (5-200 μg/cm(2), corresponding to 19-760 μg/ml) for 24 and 48h in the comet assay and for 48 and 72 h in the MN and M1dG assays. Transmission electron microscopy (TEM) showed more MWCNT fibres and SWCNT clusters in BEAS 2B than MeT-5A cells, but no significant differences were seen in intracellular dose expressed as area of SWCNT clusters between TEM sections of the cell lines. In MeT-5A cells, both CNTs caused a dose-dependent induction of DNA damage (% DNA in comet tail) in the 48-h treatment and SWCNTs additionally in the 24-h treatment, with a statistically significant increase at 40 μg/cm(2) of SWCNTs and (after 48 h) 80 μg/cm(2) of both CNTs. SWCNTs also elevated the level of M1dG DNA adducts at 1, 5, 10 and 40 μg/cm(2) after the 48-h treatment, but both CNTs decreased M1dG adduct level at several doses after the 72-h treatment. In BEAS 2B cells, SWCNTs induced a statistically significant increase in DNA damage at 80 and 120 μg/cm(2) after the 24-h treatment and in M1dG adduct level at 5 μg/cm(2) after 48 h and 10 and 40 μg/cm(2) after 72 h; MWCNTs did not affect the level of DNA damage but produced a decrease in M1dG adducts in the 72-h treatment. The CNTs did not affect the level of

  14. [ACE inhibitors and the kidney].

    PubMed

    Hörl, W H

    1996-01-01

    Treatment with ACE inhibitors results in kidney protection due to reduction of systemic blood pressure, intraglomerular pressure, an antiproliferative effect, reduction of proteinuria and a lipid-lowering effect in proteinuric patients (secondary due to reduction of protein excretion). Elderly patients with diabetes melitus, coronary heart disease or peripheral vascular occlusion are at risk for deterioration of kidney function due to a high frequency of renal artery stenosis in these patients. In patients with renal insufficiency dose reduction of ACE inhibitors is necessary (exception: fosinopril) but more important is the risk for development of hyperkalemia. Patients at risk for renal artery stenosis and patients pretreated with diuretics should receive a low ACE inhibitor dosage initially ("start low - go slow"). For compliance reasons once daily ACE inhibitor dosage is recommended.

  15. A20 overexpression inhibits lipopolysaccharide-induced NF-κB activation, TRAF6 and CD40 expression in rat peritoneal mesothelial cells.

    PubMed

    Zou, Xun-Liang; Pei, De-An; Yan, Ju-Zhen; Xu, Gang; Wu, Ping

    2014-04-17

    Zinc finger protein A20 is a key negative regulator of inflammation. However, whether A20 may affect inflammation during peritoneal dialysis (PD)-associated peritonitis is still unclear. This study was aimed to investigate the effect of A20 overexpression on lipopolysaccharide (LPS)-induced inflammatory response in rat peritoneal mesothelial cells (RPMCs). Isolated and cultured RPMCs in vitro. Plasmid pGEM-T easy-A20 was transfected into RPMCs by Lipofectamine™2000. The protein expression of A20, phospho-IκBα, IκBα, TNF receptor-associated factor (TRAF) 6 and CD40 were analyzed by Western blot. The mRNA expression of TRAF6, CD40, interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) were determined by real time-PCR. NF-κB p65 DNA binding activity, IL-6 and TNF-α levels in cells culture supernatant were determined by ELISA. Our results revealed that RPMCs overexpression of A20 lead to significant decrease of LPS-induced IκBα phosphorylation and NF-κB DNA binding activity (all p<0.01). In addition, A20 also attenuated the expression of TRAF6, CD40, IL-6 and TNF-α as well as levels of IL-6 and TNF-α in cells culture supernatant (all p<0.05). However, A20 only partly inhibited CD40 expression. Our study indicated that A20 overexpression may depress the inflammatory response induced by LPS in cultured RPMCs through negatively regulated the relevant function of adaptors in LPS signaling pathway.

  16. Diagnostic usefulness of EMA, IMP3, and GLUT-1 for the immunocytochemical distinction of malignant cells from reactive mesothelial cells in effusion cytology using cytospin preparations.

    PubMed

    Ikeda, Katsuhide; Tate, Genshu; Suzuki, Takao; Kitamura, Takashi; Mitsuya, Toshiyuki

    2011-06-01

    To differentiate reactive mesothelial cells (RMs) from metastatic carcinoma and malignant mesothelioma (MM) in effusion cytology is crucial for the cytologic diagnosis and the management of the patients. In the present study, the immunocytochemical staining profile of the epithelial membrane antigen (EMA), the insulin-like growth factor-II mRNA-binding protein 3 (IMP3), and the glucose transporter-1 (GLUT-1) was examined to distinguish RMs from malignant cells. A total of 171 pleural (n = 87) and peritoneal (n = 84) effusion specimens, including 50 benign effusions with RMs, 11 MM effusions, and 110 metastatic malignant effusions, were evaluated for immunocytochemistry. EMA, IMP3, monoclonal GLUT-1, and polyclonal GLUT-1 immunoreactivity were observed in 26.0%, 6.0%, 20.0%, and 18.0% of RMs, respectively. In contrast to RMs, the immunoreactivity in MM was 100%, 36.4%, 100%, and 90.9%; adenocarcinoma (AC) was 100%, 80.8%, 81.7%, and 72.1%; squamous-cell carcinoma was 83.3%, 83.3%, 83.3%, and 66.7%. EMA, IMP3, mGLUT-1, and pGLUT-1 expressions were observed in 98.4%, 65.6%, 88.5%, and 75.4% in the pleural effusion with malignant cells, and 100%, 88.3%, 78.3%, and 71.7% in ascites containing malignant cells, respectively. The findings of the present study indicate that the immunocytochemical staining for EMA, IMP3, and GLUT-1 is a useful diagnostic tool for distinguishing effusions containing malignant cells from those that contain benign cells, and in particular, we suggest that the combination of mGLUT-1 and EMA, and IMP3 and EMA are extremely useful in pleural effusion and in ascites, respectively.

  17. Vitamin D Can Ameliorate Chlorhexidine Gluconate-Induced Peritoneal Fibrosis and Functional Deterioration through the Inhibition of Epithelial-to-Mesenchymal Transition of Mesothelial Cells

    PubMed Central

    Lee, Yi-Che; Hung, Shih-Yuan; Liou, Hung-Hsiang; Lin, Tsun-Mei; Tsai, Chu-Hung; Lin, Sheng-Hsiang; Tsai, Yau-Sheng; Chang, Min-Yu; Wang, Hsi-Hao; Ho, Li-Chun; Chen, Yi-Ting; Wu, Ching-Fang; Chen, Ho-Ching; Chen, Hsin-Pao; Liu, Kuang-Wen; Chen, Chih-I.; She, Kuan Min; Wang, Hao-Kuang; Lin, Chi-Wei; Chiou, Yuan-Yow

    2015-01-01

    Background. Peritoneal dialysis (PD) can induce fibrosis and functional alterations in PD patients' peritoneal membranes, due to long-term unphysiological dialysate exposure, partially occurring via triggering of epithelial-to-mesenchymal transition (EMT) in peritoneal mesothelial cells (MCs). Vitamin D can ameliorate these negative effects; however, the mechanism remains unexplored. Therefore, we investigated its possible links to MCs EMT inhibition. Methods. Peritoneal fibrosis was established in Sprague-Dawley rats by chlorhexidine gluconate (CG) intraperitoneal injection for 21 days, with and without 1α,25(OH)2D3 treatment. Morphological and functional evaluation and western blot analysis of EMT marker were performed upon peritoneum tissue. In vitro study was also performed in a primary human peritoneal MC culture system; MCs were incubated with transforming growth factor-β1 (TGF-β1) in the absence or presence of 1α,25(OH)2D3. EMT marker expression, migration activities, and cytoskeleton redistribution of MCs were determined. Results. 1α,25(OH)2D3 ameliorated CG-induced morphological and functional deterioration in animal model, along with CG-induced upregulation of α-SMA and downregulation of E-cadherin expression. Meanwhile, 1α,25(OH)2D3 also ameliorated TGF-β1-induced decrease in E-cadherin expression, increase in Snai1 and α-SMA expression, intracellular F-actin redistribution, and migration activity in vitro. Conclusion. 1α,25(OH)2D3 can ameliorate CG-induced peritoneal fibrosis and attenuate functional deterioration through inhibiting MC EMT. PMID:26495304

  18. Role of fibre characteristics on cytotoxicity and induction of anaphase/telophase aberrations in rat pleural mesothelial cells in vitro: correlations with in vivo animal findings.

    PubMed

    Yegles, M; Janson, X; Dong, H Y; Renier, A; Jaurand, M C

    1995-11-01

    Thirteen samples of natural fibres and five samples of man-made fibres (MMF) were tested to determine their cytotoxicity and ability to produce chromosome missegregation in cultures in rat pleural mesothelial cells (RPMC). The natural samples included attapulgite, two amphiboles (amosite and crocidolite); seven consisted of chrysotile from various origins and three were obtained after chemical treatment of chrysotile. MMF included three refractory ceramic fibres (RCF) and two vitreous fibres (MMVF). All fibre samples were characterized by electron microscopic measurement of the fibre dimensions. Cytotoxicity was assayed on the basis of determination of mitochondrial integrity and chromosome missegregation by light microscopy examination of anaphases/telophases. The carcinogenic potency of 10 natural samples has been previously investigated using intrapleural inoculation in rats. It was therefore possible to establish correlations between in vitro and in vivo data obtained with the same set of samples. The various samples of chrysotile produced different in vitro effects, in agreement with the dispersion of response also observed in vivo. Cytotoxicity appears to be dependent on both fibre length and fibre diameter, as the longest or thickest fibres were the most toxic. The production of abnormal anaphases/telophases appears to depend on the presence of fibres of selected size, such as those previously defined by Stanton et al. (L > 8 micrograms; D < or = 0.25 microns); a threshold values was determined below which no abnormal anaphases/telophases were detected. This non-observable effect level was estimated to be 2.5 x 10(5) 'Stanton' fibres per cm2. There was no correlation between cytotoxicity and mesothelioma induction; in contrast, a correlation was found between the ability of a sample to produce chromosome missegregation in vitro and mesothelioma in vivo.

  19. Protective role of sodium butyrate, a HDAC inhibitor on beta-cell proliferation, function and glucose homeostasis through modulation of p38/ERK MAPK and apoptotic pathways: study in juvenile diabetic rat.

    PubMed

    Khan, S; Jena, G B

    2014-04-25

    Type 1 diabetes (T1D) also known as juvenile diabetes is a chronic autoimmune disorder that precipitates in genetically susceptible individuals by environmental factors particularly during early age. Both genetic and epigenetic factors are implicated in the beta-cell development, proliferation, differentiation and function. Recent evidences suggested that there is a link between diabetes and histone deacetylases (HDACs), because HDAC inhibitors promote beta-cell development, proliferation and function as well as improve glucose homeostasis. Sodium butyrate (NaB) is a short chain fatty acid having HDAC inhibition activity. The present study was aimed to investigate the protective role of NaB treatment on the beta-cell proliferation, function and glucose homeostasis as well as apoptosis in juvenile diabetic rat. Diabetes was induced by single injection of STZ (60 mg/kg, i.p.) in chilled citrate buffer, while NaB (500 mg/kg/day) was administrated by i.p. route for 21 days as pre- and post-treatment schedule. Plasma glucose and insulin levels, HbA1c, glucose tolerance, apoptosis, and expression of proliferating cell nuclear antigen (PCNA), p38, p53, caspase-3, extracellular signal-regulated kinase-1/2 (ERK-1/2), forkhead box protein O1 (FOXO1) and insulin receptor substrate-1 (IRS-1) as well as histone acetylation were evaluated. NaB treatment decreased plasma glucose, HbA1c, beta-cell apoptosis and improved plasma insulin level and glucose homeostasis through HDAC inhibition and histone acetylation in diabetic animal as compared to control. NaB treatment improved the beta-cell proliferation, function and glucose homeostasis as well as reduced beta-cell apoptosis in juvenile diabetic rat by the modulation of p38/ERK MAPK and apoptotic pathway.

  20. Protection from extinction.

    PubMed

    Rescorla, Robert A

    2003-05-01

    The effect of the presence of a conditioned inhibitor on extinction of excitatory conditioning was studied in one magazine approach and three autoshaping experiments using rats and pigeons. In each case, the presence of an inhibitor reduced responding to an exciter during extinction but allowed substantial recovery of responding to that exciter when subsequently tested separately. Control stimuli with a history of being irrelevant to reinforcement or being nonreinforced had less of a protective effect. This constitutes a clear demonstration of protection from extinction, a phenomenon of substantial theoretical and applied importance.

  1. Autophagy inhibitors.

    PubMed

    Pasquier, Benoit

    2016-03-01

    Autophagy is a lysosome-dependent mechanism of intracellular degradation. The cellular and molecular mechanisms underlying this process are highly complex and involve multiple proteins, including the kinases ULK1 and Vps34. The main function of autophagy is the maintenance of cell survival when modifications occur in the cellular environment. During the past decade, extensive studies have greatly improved our knowledge and autophagy has exploded as a research field. This process is now widely implicated in pathophysiological processes such as cancer, metabolic, and neurodegenerative disorders, making it an attractive target for drug discovery. In this review, we will summarize the different types of inhibitors that affect the autophagy machinery and provide some potential therapeutic perspectives.

  2. Influence of Bicarbonate/Low-GDP Peritoneal Dialysis Fluid (Bicavera) on In Vitro and Ex Vivo Epithelial-to-Mesenchymal Transition of Mesothelial Cells

    PubMed Central

    Fernández–Perpén, Antonio; Pérez–Lozano, María Luisa; Bajo, María–Auxiliadora; Albar–Vizcaino, Patricia; Correa, Pilar Sandoval; del Peso, Gloria; Castro, María–José; Aguilera, Abelardo; Ossorio, Marta; Peter, Mirjam E.; Passlick–Deetjen, Jutta; Aroeira, Luiz S.; Selgas, Rafael; López–Cabrera, Manuel; Sánchez–Tomero, J. Antonio

    2012-01-01

    ♦ Background: Peritoneal membrane damage induced by peritoneal dialysis (PD) is largely associated with epithelial-to-mesenchymal transition (EMT) of mesothelial cells (MCs), which is believed to be a result mainly of the glucose degradation products (GDPs) present in PD solutions. ♦ Objectives: This study investigated the impact of bicarbonate-buffered, low-GDP PD solution (BicaVera: Fresenius Medical Care, Bad Homburg, Germany) on EMT of MCs in vitro and ex vivo. ♦ Methods: In vitro studies: Omentum-derived MCs were incubated with lactate-buffered standard PD fluid or BicaVera fluid diluted 1:1 with culture medium. Ex vivo studies: From 31 patients randomly distributed to either standard or BicaVera solution and followed for 24 months, effluents were collected every 6 months for determination of EMT markers in effluent MCs. ♦ Results: Culturing of MCs with standard fluid in vitro resulted in morphology change to a non-epithelioid shape, with downregulation of E-cadherin (indicative of EMT) and strong induction of vascular endothelial growth factor (VEGF) expression. By contrast, in vitro exposure of MCs to bicarbonate/low-GDP solution had less impact on both EMT parameters. Ex vivo studies partially confirmed the foregoing results. The BicaVera group, with a higher prevalence of the non-epithelioid MC phenotype at baseline (for unknown reasons), showed a clear and significant trend to gain and maintain an epithelioid phenotype at medium- and longer-term and to show fewer fibrogenic characteristics. By contrast, the standard solution group demonstrated a progressive and significantly higher presence of the non-epithelioid phenotype. Compared with effluent MCs having an epithelioid phenotype, MCs with non-epithelioid morphology showed significantly lower levels of E-cadherin and greater levels of fibronectin and VEGF. In comparing the BicaVera and standard solution groups, MCs from the standard solution group showed significantly higher secretion of

  3. [Ultrastructure of peritoneal mesothelial cells].

    PubMed

    Obradovic, M M; Stojimirovic, B B; Trpinac, D P; Milutinovic, D D; Obradovic, D I; Nesic, V B

    2001-01-01

    The introduction of peritoneal dialysis (PD) as a respectable modality of renal replacement therapy some three decades ago, suddenly drew attention of many authors to peritoneal membrane as insufficiently investigated structure. In order to explain the pathological changes in peritoneum due to renal diseases, it became necessary to explore the normal peritoneal structure. The aim of this study was to examine the morphology of peritoneal lining cells in healthy persons. Biopsies of the peritoneum were performed on 20 volunteer kidney donors. Tissue samples were taken during renal transplantation. Special care was taken in getting appropriate samples without artificial damage because of the extreme fragility of the peritoneal tissue. The preparing procedure was standard for routine HE staining and for plastic embedded semifine and fine sections studies. Semifine sections were made on ultramicrotome, stained with Toluidin blue and studied by light microscope, while fine sections were made by ultramicrotome and studied by transmission electron microscope. One layer of cuboidal or flattened lining cells present over the lamina propria connective tissue presented mesothelium. The cells were overlapped like tiles on the roof. Lateral parts of their interdigitated membranes were interconnected with different types of cell junctions: unpermeable, adhesion and communication junctions; inhibiting intercellular transport. Cell surface was often covered with great number of microvilli and lamellar bodies. A single kinocilia was also often present on apical cell surface. Nuclei were euchromatic with well developed nucleoli. Cytoplasm was filled with a great number of ribosomes, mitochondria, cisterns of rough endoplasmatic reticulum and Golgi apparatus, lamellar bodies and lipid inclusions. Numerous pinocytic vesicles on all parts of the membrane as well as in the cytoplasm indicating active endocytosis, egsocytosis and transcytosys in the process of secretion and reabsorption of serous liquid in peritoneal cavity, were visible. Euchromatic nuclei with prominent nucleoli and numerous mitochondria indicate cells of great metabolic activity.

  4. Rapamycin Protects from Type-I Peritoneal Membrane Failure Inhibiting the Angiogenesis, Lymphangiogenesis, and Endo-MT

    PubMed Central

    Aguirre, Anna Rita; Loureiro, Jesús; Abensur, Hugo; Sandoval, Pilar; Sánchez-Tomero, José Antonio; del Peso, Gloria; Jiménez-Heffernan, José Antonio; Ruiz-Carpio, Vicente; Selgas, Rafael; López-Cabrera, Manuel; Aguilera, Abelardo; Liappas, Georgios

    2015-01-01

    Preservation of peritoneal membrane (PM) is essential for long-term survival in peritoneal dialysis (PD). Continuous presence of PD fluids (PDF) in the peritoneal cavity generates chronic inflammation and promotes changes of the PM, such as fibrosis, angiogenesis, and lymphangiogenesis. Mesothelial-to-mesenchymal transition (MMT) and endothelial-to-mesenchymal transition (Endo-MT) seem to play a central role in this pathogenesis. We speculated that Rapamycin, a potent immunosuppressor, could be beneficial by regulating blood and lymphatic vessels proliferation. We demonstrate that mice undergoing a combined PD and Rapamycin treatment (PDF + Rapa group) presented a reduced PM thickness and lower number of submesothelial blood and lymphatic vessels, as well as decreased MMT and Endo-MT, comparing with their counterparts exposed to PD alone (PDF group). Peritoneal water transport in the PDF + Rapa group remained at control level, whereas PD effluent levels of VEGF, TGF-β, and TNF-α were lower than in the PDF group. Moreover, the treatment of mesothelial cells with Rapamycin in vitro significantly decreased VEGF synthesis and selectively inhibited the VEGF-C and VEGF-D release when compared with control cells. Thus, Rapamycin has a protective effect on PM in PD through an antifibrotic and antiproliferative effect on blood and lymphatic vessels. Moreover, it inhibits Endo-MT and, at least partially, MMT. PMID:26688823

  5. Rapamycin Protects from Type-I Peritoneal Membrane Failure Inhibiting the Angiogenesis, Lymphangiogenesis, and Endo-MT.

    PubMed

    González-Mateo, Guadalupe Tirma; Aguirre, Anna Rita; Loureiro, Jesús; Abensur, Hugo; Sandoval, Pilar; Sánchez-Tomero, José Antonio; del Peso, Gloria; Jiménez-Heffernan, José Antonio; Ruiz-Carpio, Vicente; Selgas, Rafael; López-Cabrera, Manuel; Aguilera, Abelardo; Liappas, Georgios

    2015-01-01

    Preservation of peritoneal membrane (PM) is essential for long-term survival in peritoneal dialysis (PD). Continuous presence of PD fluids (PDF) in the peritoneal cavity generates chronic inflammation and promotes changes of the PM, such as fibrosis, angiogenesis, and lymphangiogenesis. Mesothelial-to-mesenchymal transition (MMT) and endothelial-to-mesenchymal transition (Endo-MT) seem to play a central role in this pathogenesis. We speculated that Rapamycin, a potent immunosuppressor, could be beneficial by regulating blood and lymphatic vessels proliferation. We demonstrate that mice undergoing a combined PD and Rapamycin treatment (PDF + Rapa group) presented a reduced PM thickness and lower number of submesothelial blood and lymphatic vessels, as well as decreased MMT and Endo-MT, comparing with their counterparts exposed to PD alone (PDF group). Peritoneal water transport in the PDF + Rapa group remained at control level, whereas PD effluent levels of VEGF, TGF-β, and TNF-α were lower than in the PDF group. Moreover, the treatment of mesothelial cells with Rapamycin in vitro significantly decreased VEGF synthesis and selectively inhibited the VEGF-C and VEGF-D release when compared with control cells. Thus, Rapamycin has a protective effect on PM in PD through an antifibrotic and antiproliferative effect on blood and lymphatic vessels. Moreover, it inhibits Endo-MT and, at least partially, MMT.

  6. The LRRK2 inhibitor GSK2578215A induces protective autophagy in SH-SY5Y cells: involvement of Drp-1-mediated mitochondrial fission and mitochondrial-derived ROS signaling

    PubMed Central

    Saez-Atienzar, S; Bonet-Ponce, L; Blesa, J R; Romero, F J; Murphy, M P; Jordan, J; Galindo, M F

    2014-01-01

    Mutations in the leucine-rich repeat kinase 2 (LRRK2) gene have been associated with Parkinson's disease, and its inhibition opens potential new therapeutic options. Among the drug inhibitors of both wild-type and mutant LRRK2 forms is the 2-arylmethyloxy-5-subtitutent-N-arylbenzamide GSK257815A. Using the well-established dopaminergic cell culture model SH-SY5Y, we have investigated the effects of GSK2578215A on crucial neurodegenerative features such as mitochondrial dynamics and autophagy. GSK2578215A induces mitochondrial fragmentation of an early step preceding autophagy. This increase in autophagosome results from inhibition of fusion rather than increases in synthesis. The observed effects were shared with LRRK2-IN-1, a well-described, structurally distinct kinase inhibitor compound or when knocking down LRRK2 expression using siRNA. Studies using the drug mitochondrial division inhibitor 1 indicated that translocation of the dynamin-related protein-1 has a relevant role in this process. In addition, autophagic inhibitors revealed the participation of autophagy as a cytoprotective response by removing damaged mitochondria. GSK2578215A induced oxidative stress as evidenced by the accumulation of 4-hydroxy-2-nonenal in SH-SY5Y cells. The mitochondrial-targeted reactive oxygen species scavenger MitoQ positioned these species as second messengers between mitochondrial morphologic alterations and autophagy. Altogether, our results demonstrated the relevance of LRRK2 in mitochondrial-activated pathways mediating in autophagy and cell fate, crucial features in neurodegenerative diseases. PMID:25118928

  7. Radiation Protection

    MedlinePlus

    Jump to main content US EPA United States Environmental Protection Agency Search Search Radiation Protection Share Facebook Twitter Google+ Pinterest Contact Us Radiation Protection Document Library View ...

  8. Proton pump inhibitors

    MedlinePlus

    Proton pump inhibitors (PPIs) are medicines that work by reducing the amount of stomach acid made by ... Proton pump inhibitors are used to: Relieve symptoms of acid reflux, or gastroesophageal reflux disease (GERD). This ...

  9. Corrosion inhibitors for solar-heating and cooling

    NASA Technical Reports Server (NTRS)

    Humphries, T. S.

    1979-01-01

    Report describes results of tests conducted to evaluate abilities of 12 candidate corrosion inhibitors to protect aluminum, steel, copper, or stainless steel at typical conditions encountered in solar heating and cooling systems. Inhibitors are based on sodium salts including nitrates, borates, silicates, and phosphates.

  10. Electrochemical corrosion testing: An effective tool for corrosion inhibitor evaluation

    SciTech Connect

    Bartley, L.S.; Van de Ven, P.; Mowlem, J.K.

    1996-10-01

    Corrosivity of an Antifreeze/Coolant can lead to localized attacks which are a major cause for metal failure. To prevent this phenomenon, specific corrosion inhibitors are used to protect the different metals in service. This paper will discuss the electrochemical principles behind corrosion, Realized corrosion and corrosion inhibition. It will also discuss electrochemical techniques which allow for the evaluation of these inhibitors.

  11. Inhibitors of Pyruvate Carboxylase

    PubMed Central

    Zeczycki, Tonya N.; Maurice, Martin St.; Attwood, Paul V.

    2010-01-01

    This review aims to discuss the varied types of inhibitors of biotin-dependent carboxylases, with an emphasis on the inhibitors of pyruvate carboxylase. Some of these inhibitors are physiologically relevant, in that they provide ways of regulating the cellular activities of the enzymes e.g. aspartate and prohibitin inhibition of pyruvate carboxylase. Most of the inhibitors that will be discussed have been used to probe various aspects of the structure and function of these enzymes. They target particular parts of the structure e.g. avidin – biotin, FTP – ATP binding site, oxamate – pyruvate binding site, phosphonoacetate – binding site of the putative carboxyphosphate intermediate. PMID:22180764

  12. Acquired Factor V Inhibitor

    PubMed Central

    Hirai, Daisuke; Yamashita, Yugo; Masunaga, Nobutoyo; Katsura, Toshiaki; Akao, Masaharu; Okuno, Yoshiaki; Koyama, Hiroshi

    2016-01-01

    Inhibitors directed against factor V rarely occur, and the clinical symptoms vary. We herein report the case of a patient who presented with a decreased factor V activity that had decreased to <3 %. We administered vitamin K and 6 units of fresh frozen plasma, but she thereafter developed an intracerebral hemorrhage. It is unclear whether surgery >10 years earlier might have caused the development of a factor V inhibitor. The treatment of acquired factor V inhibitors is mainly the transfusion of platelet concentrates and corticosteroids. Both early detection and the early initiation of the treatment of factor V inhibitor are thus considered to be important. PMID:27746446

  13. CRYSTALLINE SOYBEAN TRYPSIN INHIBITOR

    PubMed Central

    Kunitz, M.

    1947-01-01

    A study has been made of the general properties of crystalline soybean trypsin inhibitor. The soy inhibitor is a stable protein of the globulin type of a molecular weight of about 24,000. Its isoelectric point is at pH 4.5. It inhibits the proteolytic action approximately of an equal weight of crystalline trypsin by combining with trypsin to form a stable compound. Chymotrypsin is only slightly inhibited by soy inhibitor. The reaction between chymotrypsin and the soy inhibitor consists in the formation of a reversibly dissociable compound. The inhibitor has no effect on pepsin. The inhibiting action of the soybean inhibitor is associated with the native state of the protein molecule. Denaturation of the soy protein by heat or acid or alkali brings about a proportional decrease in its inhibiting action on trypsin. Reversal of denaturation results in a proportional gain in the inhibiting activity. Crystalline soy protein when denatured is readily digestible by pepsin, and less readily by chymotrypsin and by trypsin. Methods are given for measuring trypsin and inhibitor activity and also protein concentration with the aid of spectrophotometric density measurements at 280 mµ. PMID:19873496

  14. Hydroxyapatite microparticles as feedback-active reservoirs of corrosion inhibitors.

    PubMed

    Snihirova, D; Lamaka, S V; Taryba, M; Salak, A N; Kallip, S; Zheludkevich, M L; Ferreira, M G S; Montemor, M F

    2010-11-01

    This work contributes to the development of new feedback-active anticorrosion systems. Inhibitor-doped hydroxyapatite microparticles (HAP) are used as reservoirs, storing corrosion inhibitor to be released on demand. Release of the entrapped inhibitor is triggered by redox reactions associated with the corrosion process. HAP were used as reservoirs for several inhibiting species: cerium(III), lanthanum(III), salicylaldoxime, and 8-hydroxyquinoline. These species are effective corrosion inhibitors for a 2024 aluminum alloy (AA2024), used here as a model metallic substrate. Dissolution of the microparticles and release of the inhibitor are triggered by local acidification resulting from the anodic half-reaction during corrosion of AA2024. Calculated values and experimentally measured local acidification over the aluminum anode (down to pH = 3.65) are presented. The anticorrosion properties of inhibitor-doped HAP were assessed using electrochemical impedance spectroscopy. The microparticles impregnated with the corrosion inhibitors were introduced into a hybrid silica-zirconia sol-gel film, acting as a thin protective coating for AA2024, an alloy used for aeronautical applications. The protective properties of the sol-gel films were improved by the addition of HAP, proving their applicability as submicrometer-sized reservoirs of corrosion inhibitors for active anticorrosion coatings.

  15. Polypeptide Inhibitors of Mineral Scaling and Corrosion

    DTIC Science & Technology

    1989-06-01

    formation. A thermal method of synthesis of polyaspartate based on peptide bond formation in dry powders of aspartic acid at around 200 C was developed...peptides are based on natural protein inhibitors of mineral formation and generally are enriched in aspartic acid and phosphoserine. Specifically, the...AsP5 to AsP60 was synthesized by repetitive couplings of t-Boc-L- aspartic acid residues with B-carboxyl protection by O-benzyl linkage. A C-terminal

  16. Inhibitors Selective for Mycobacterial Versus Human Proteasomes

    SciTech Connect

    Lin, G.; Li, D; Sorio de Carvalho, L; Deng, H; Tao, H; Vogt, G; Wu, K; Schneider, J; Chidawanyika, T; et. al.

    2009-01-01

    Many anti-infectives inhibit the synthesis of bacterial proteins, but none selectively inhibits their degradation. Most anti-infectives kill replicating pathogens, but few preferentially kill pathogens that have been forced into a non-replicating state by conditions in the host. To explore these alternative approaches we sought selective inhibitors of the proteasome of Mycobacterium tuberculosis. Given that the proteasome structure is extensively conserved, it is not surprising that inhibitors of all chemical classes tested have blocked both eukaryotic and prokaryotic proteasomes, and no inhibitor has proved substantially more potent on proteasomes of pathogens than of their hosts. Here we show that certain oxathiazol-2-one compounds kill non-replicating M.?tuberculosis and act as selective suicide-substrate inhibitors of the M.?tuberculosis proteasome by cyclocarbonylating its active site threonine. Major conformational changes protect the inhibitor-enzyme intermediate from hydrolysis, allowing formation of an oxazolidin-2-one and preventing regeneration of active protease. Residues outside the active site whose hydrogen bonds stabilize the critical loop before and after it moves are extensively non-conserved. This may account for the ability of oxathiazol-2-one compounds to inhibit the mycobacterial proteasome potently and irreversibly while largely sparing the human homologue.

  17. Protective Eyewear

    MedlinePlus

    ... Home > NEI for Kids > Protective Eyewear All About Vision About the Eye Ask a Scientist Video Series ... Eye Health and Safety First Aid Tips Healthy Vision Tips Protective Eyewear Sports and Your Eyes Fun ...

  18. Both the H2S biosynthesis inhibitor aminooxyacetic acid and the mitochondrially targeted H2S donor AP39 exert protective effects in a mouse model of burn injury.

    PubMed

    Ahmad, Akbar; Szabo, Csaba

    2016-11-01

    Hydrogen sulfide (H2S) exerts beneficial as well as deleterious effects in various models of critical illness. Here we tested the effect of two different pharmacological interventions: (a) inhibition of H2S biosynthesis using the cystathionine-beta-synthase (CBS)/cystathionine-gamma-lyase (CSE) inhibitor aminooxyacetic acid (AOAA) and the mitochondrially targeted H2S donor [10-oxo-10-[4-(3-thioxo-3H-1,2-dithiol-5-yl)phenoxy]decyl]triphenyl-phosphonium (AP39). A 30% body surface area burn injury was induced in anesthetized mice; animals were treated with vehicle, AOAA (10mg/kg i.p. once or once a day for 6days), or AP39 (0.3mg/kg/day once or once a day for 6days). In two separate groups, animals were sacrificed, at 24h post-burn or on Day 7 post-burn, blood and lungs were collected and the following parameters were evaluated: myeloperoxidase (MPO) and malondialdehyde (MDA) in lung homogenates, plasma cytokines (Luminex analysis) and circulating indicators of organ dysfunction (Vetscan analysis). Lung MPO levels (an index of neutrophil infiltration) and MDA levels (an index of oxidative stress) were significantly increased in response to burn injury both at 24h and at 7days; both AOAA and AP39 attenuated these increases. From a panel of inflammatory cytokines (TNFα, IL-1β, IL-6, IL-10, MCP-1, MIP-2, VEGF and IFNγ) in the plasma, IL-6 and IL-10 levels were markedly elevated at 24h and VEGF was slightly elevated. IL-6 remained highly elevated at 7days post-burn while IL-10 levels decreased, but remained slightly elevated over baseline 7days post-burn. The changes in cytokine levels were attenuated both by AP39 and AOAA at both time points studied. The burn-induced increases in the organ injury markers ALP and ALT, amylase and creatinine were reduced by both AOAA and AP39. We conclude that both H2S biosynthesis inhibition (using AOAA) and H2S donation (using AP39) suppresses inflammatory mediator production and reduces multi-organ injury in a murine model of burn

  19. Corrosion inhibitors for solar heating and cooling systems

    NASA Technical Reports Server (NTRS)

    Humphries, T. S.; Deramus, G. E., Jr.

    1977-01-01

    Problems dealing with corrosion and corrosion protection of solar heating and cooling systems are discussed. A test program was conducted to find suitable and effective corrosion inhibitors for systems employing either water or antifreeze solutions for heat transfer and storage. Aluminum-mild-steel-copper-stainless steel assemblies in electrical contact were used to simulate a multimetallic system which is the type most likely to be employed. Several inhibitors show promise for this application.

  20. Waste of cleaning emulsion sewage as inhibitors of steel corrosion

    NASA Astrophysics Data System (ADS)

    Fazullin, D. D.; Mavrin, G. V.; Shaikhiev, I. G.

    2016-06-01

    The article describes the corrosion test of steel of the brand 20 in the stratal water. To increase corrosion resistance as a corrosion inhibitor the concentrate waste emulsion of the mark "Incam- 1" was provided. The article presents studies of the corrosion rate with different dosages of corrosion inhibitor in the stratal water. Based on these research results are revealed that the degree of protection of steel is 27% at a dosage of 3.8 g / dm3.

  1. SGLT2 inhibitors.

    PubMed

    Dardi, I; Kouvatsos, T; Jabbour, S A

    2016-02-01

    Diabetes mellitus is a serious health issue and an economic burden, rising in epidemic proportions over the last few decades worldwide. Although several treatment options are available, only half of the global diabetic population achieves the recommended or individualized glycemic targets. Sodium-glucose cotransporter 2 (SGLT2) inhibitors are a new class of antidiabetic agents with a novel insulin-independent action. SGLT2 is a transporter found in the proximal renal tubules, responsible for the reabsorption of most of the glucose filtered by the kidney. Inhibition of SGLT2 lowers the blood glucose level by promoting the urinary excretion of excess glucose. Due to their insulin-independent action, SGLT2 inhibitors can be used with any degree of beta-cell dysfunction or insulin resistance, related to a very low risk of hypoglycemia. In addition to improving glycemic control, SGLT2 inhibitors have been associated with a reduction in weight and blood pressure when used as monotherapy or in combination with other antidiabetic agents in patients with type 2 diabetes mellitus (T2DM). Treatment with SGLT2 inhibitors is usually well tolerated; however, they have been associated with an increased incidence of urinary tract and genital infections, although these infections are usually mild and easy to treat. SGLT2 inhibitors are a promising new option in the armamentarium of drugs for patients with T2DM.

  2. [Acquired coagulant factor inhibitors].

    PubMed

    Nogami, Keiji

    2015-02-01

    Acquired coagulation factor inhibitors are an autoimmune disease causing bleeding symptoms due to decreases in the corresponding factor (s) which result from the appearance of autoantibodies against coagulation factors (inhibitor). This disease is quite different from congenital coagulation factor deficiencies based on genetic abnormalities. In recent years, cases with this disease have been increasing, and most have anti-factor VIII autoantibodies. The breakdown of the immune control mechanism is speculated to cause this disease since it is common in the elderly, but the pathology and pathogenesis are presently unclear. We herein describe the pathology and pathogenesis of factor VIII and factor V inhibitors. Characterization of these inhibitors leads to further analysis of the coagulation process and the activation mechanisms of clotting factors. In the future, with the development of new clotting examination method (s), we anticipate that further novel findings will be obtained in this field through inhibitor analysis. In addition, detailed elucidation of the coagulation inhibitory mechanism possibly leading to hemostatic treatment strategies for acquired coagulation factor disorders will be developed.

  3. Therapeutic potential of monoacylglycerol lipase inhibitors.

    PubMed

    Mulvihill, Melinda M; Nomura, Daniel K

    2013-03-19

    Marijuana and aspirin have been used for millennia to treat a wide range of maladies including pain and inflammation. Both cannabinoids, like marijuana, that exert anti-inflammatory action through stimulating cannabinoid receptors, and cyclooxygenase (COX) inhibitors, like aspirin, that suppress pro-inflammatory eicosanoid production have shown beneficial outcomes in mouse models of neurodegenerative diseases and cancer. Both cannabinoids and COX inhibitors, however, have untoward effects that discourage their chronic usage, including cognitive deficits and gastrointestinal toxicity, respectively. Recent studies have uncovered that the serine hydrolase monoacylglycerol lipase (MAGL) links the endocannabinoid and eicosanoid systems together through hydrolysis of the endocannabinoid 2-arachidonoylglycerol (2-AG) to provide the major arachidonic acid (AA) precursor pools for pro-inflammatory eicosanoid synthesis in specific tissues. Studies in recent years have shown that MAGL inhibitors elicit anti-nociceptive, anxiolytic, and anti-emetic responses and attenuate precipitated withdrawal symptoms in addiction paradigms through enhancing endocannabinoid signaling. MAGL inhibitors have also been shown to exert anti-inflammatory action in the brain and protect against neurodegeneration through lowering eicosanoid production. In cancer, MAGL inhibitors have been shown to have anti-cancer properties not only through modulating the endocannabinoid-eicosanoid network, but also by controlling fatty acid release for the synthesis of protumorigenic signaling lipids. Thus, MAGL serves as a critical node in simultaneously coordinating multiple lipid signaling pathways in both physiological and disease contexts. This review will discuss the diverse (patho)physiological roles of MAGL and the therapeutic potential of MAGL inhibitors in treating a vast array of complex human diseases.

  4. Cholinesterase inhibitors from botanicals

    PubMed Central

    Ahmed, Faiyaz; Ghalib, Raza Murad; Sasikala, P.; Ahmed, K. K. Mueen

    2013-01-01

    Alzheimer's disease (AD) is a progressive neurodegenerative disease, wherein a progressive loss of cholinergic synapses occurs in hippocampus and neocortex. Decreased concentration of the neurotransmitter, acetylcholine (ACh), appears to be critical element in the development of dementia, and the most appropriate therapeutic approach to treat AD and other form of dementia is to restore acetylcholine levels by inhibiting both major form of cholinesterase: Acetylcholinesterase (AChE) and butyrylcholinesterase (BChE). Consequently, researches have focused their attention towards finding cholinesterase inhibitors from natural products. A large number of such inhibitors have been isolated from medicinal plants. This review presents a comprehensive account of the advances in field of cholinesterase inhibitor phytoconstituents. The structures of some important phytoconstituents (collected through www.Chemspider.com) are also presented and the scope for future research is discussed. PMID:24347920

  5. Novel Lipid-Soluble Thiol-Redox Antioxidant and Heavy Metal Chelator, N,N′-bis(2-Mercaptoethyl)Isophthalamide (NBMI) and Phospholipase D-Specific Inhibitor, 5-Fluoro-2-Indolyl Des-Chlorohalopemide (FIPI) Attenuate Mercury-Induced Lipid Signaling Leading to Protection Against Cytotoxicity in Aortic Endothelial Cells

    PubMed Central

    Secor, Jordan D.; Kotha, Sainath R.; Gurney, Travis O.; Patel, Rishi B.; Kefauver, Nicholas R.; Gupta, Niladri; Morris, Andrew J.; Haley, Boyd E.; Parinandi, Narasimham L.

    2012-01-01

    Here, we investigated thiol-redox-mediated phospholipase D (PLD) signaling as a mechanism of mercury cytotoxicity in mouse aortic endothelial cell (MAEC) in vitro model utilizing the novel lipid-soluble thiol-redox antioxidant and heavy metal chelator, N,N′-bis(2-mercaptoethyl)isophthalamide (NBMI) and the novel PLD-specific inhibitor, 5-fluoro-2-indolyl des-chlorohalopemide (FIPI). Our results demonstrated (i) mercury in the form of mercury(II) chloride, methylmercury, and thimerosal induced PLD activation in a dose- and time-dependent manner; (ii) NBMI and FIPI completely attenuated mercury- and oxidant-induced PLD activation; (iii) mercury induced upstream phosphorylation of extracellular-regulated kinase 1/2 (ERK1/2) leading to downstream threonine phosphorylation of PLD1 which was attenuated by NBMI; (iv) mercury caused loss of intracellular glutathione which was restored by NBMI; and (v) NBMI and FIPI attenuated mercury- and oxidant-induced cytotoxicity in MAECs. For the first time, this study demonstrated that redox-dependent and PLD-mediated bioactive lipid signaling was involved in mercury-induced vascular EC cytotoxicity which was protected by NBMI and FIPI. PMID:21994240

  6. Thrombin inhibitor design.

    PubMed

    Sanderson, P E; Naylor-Olsen, A M

    1998-08-01

    Recently, iv formulated direct thrombin inhibitors have been shown to be safe and efficacious alternatives to heparin. These results have fueled the hopes for an orally active compound. Such a compound could be a significant advance over warfarin if it had predictable pharmacokinetics and a duration of action sufficient for once or twice a day dosing. In order to develop an orally active compound which meets these criteria, the deficiencies of the prototype inhibitor efegatran have had to be addressed. First, using a combination of structure based design and empirical structure optimization, more selective compounds have been identified by modifying the P1 group or by incorporating different peptidomimetic P2/P3 scaffolds. Secondly, this optimization has resulted in the development of potent and selective non-covalent inhibitors, thus bypassing the liabilities of the serine trap. Thirdly, oral bioavailability has been achieved while maintaining selectivity and efficacy through the incorporation of progressively less basic P1 groups. The duration of action of these compounds remains to be optimized. Other advances in thrombin inhibitor design have included the development of uncharged P1 groups and the discovery of two non-peptide templates.

  7. Inhibitors of the cellular trafficking of ricin.

    PubMed

    Barbier, Julien; Bouclier, Céline; Johannes, Ludger; Gillet, Daniel

    2012-01-01

    Throughout the last decade, efforts to identify and develop effective inhibitors of the ricin toxin have focused on targeting its N-glycosidase activity. Alternatively, molecules disrupting intracellular trafficking have been shown to block ricin toxicity. Several research teams have recently developed high-throughput phenotypic screens for small molecules acting on the intracellular targets required for entry of ricin into cells. These screens have identified inhibitory compounds that can protect cells, and sometimes even animals against ricin. We review these newly discovered cellular inhibitors of ricin intoxication, discuss the advantages and drawbacks of chemical-genetics approaches, and address the issues to be resolved so that the therapeutic development of these small-molecule compounds can progress.

  8. Acyclic peptide inhibitors of amylases.

    PubMed

    Pohl, Nicola

    2005-12-01

    In this issue of Chemistry and Biology, a library screening approach reveals a linear octapeptide inhibitor of alpha-amylases reached by de novo design . The selected molecule shares characteristics with naturally occurring protein inhibitors -- a result that suggests general rules for the design of peptide-based amylase inhibitors may be achievable.

  9. Memory protection

    NASA Technical Reports Server (NTRS)

    Denning, Peter J.

    1988-01-01

    Accidental overwriting of files or of memory regions belonging to other programs, browsing of personal files by superusers, Trojan horses, and viruses are examples of breakdowns in workstations and personal computers that would be significantly reduced by memory protection. Memory protection is the capability of an operating system and supporting hardware to delimit segments of memory, to control whether segments can be read from or written into, and to confine accesses of a program to its segments alone. The absence of memory protection in many operating systems today is the result of a bias toward a narrow definition of performance as maximum instruction-execution rate. A broader definition, including the time to get the job done, makes clear that cost of recovery from memory interference errors reduces expected performance. The mechanisms of memory protection are well understood, powerful, efficient, and elegant. They add to performance in the broad sense without reducing instruction execution rate.

  10. Protective Eyewear

    MedlinePlus

    ... David Turbert Reviewed by: Brenda Pagan-Duran MD Mar. 01, 2016 Eye protection means more than just ... after cataract surgery? Aug 30, 2015 Scleritis Symptoms Mar 01, 2015 Anti-reflective Coating Feb 27, 2015 ...

  11. Corrosion protection

    DOEpatents

    Brown, Donald W.; Wagh, Arun S.

    2003-05-27

    There has been invented a chemically bonded phosphate corrosion protection material and process for application of the corrosion protection material for corrosion prevention. A slurry of iron oxide and phosphoric acid is used to contact a warm surface of iron, steel or other metal to be treated. In the presence of ferrous ions from the iron, steel or other metal, the slurry reacts to form iron phosphates which form grains chemically bonded onto the surface of the steel.

  12. [SGLT2 inhibitor].

    PubMed

    Kubota, Naoto; Kadowaki, Takashi

    2015-12-01

    SGLT2 is a glucose transporter which plays an important role for reabsorption of urinary glucose depending on the sodium concentration gradient. SGLT2 is mainly present in apical site of S1 segment of renal proximal tubule and accounts for approximately 90% of total urinary glucose reabsorption. SLC5a2, which codes SGLT2, is also known as the causative gene of familial renal glucosuria. SGLT2 inhibitors are attracting attention as newly developed oral anti-diabetic agents which improve glucose intolerance and also have an anti-obese effect by promoting urinary glucose excretion (UGE), which is a different pharmacological effect from other conventional anti-diabetic agents. In this review, we will discuss the effect of SGLT2 inhibitor on the regulation of glucose and lipid metabolism in type 2 diabetes.

  13. [The influence of inhibitors of neuronal and inducible NO-synthases on experimental hemorrhagic stroke].

    PubMed

    Krushinskiĭ, A L; Kuzenkov, V S; D'iakonova, V E; Reutov, V P

    2014-01-01

    Objectives. To study the effect of inhibitors of neuronal and inducible NO-synthase on the development of hemorrhagic stroke in rats Krushinsky-Molodkina (KM) without adaptation to hypoxia and with short-term adaptation to hypobaric hypoxia. Material and methods. Ninety rats were included in the study. Experiments with short-term adaptation to hypobaric hypoxia were performed on 48 rats. The inhibitor of inducible NO-synthase (aminoguanidine, "Sigma") or the inhibitor of neuronal NO-synthase (7-nitroindasol, "Sigma") were injected in dosage 2.5 mg/100g intraperitoneally. Results. Selective inhibitors of neuronal and inducible NO-synthase had a protective effect on stress injuries in KM rats. The inhibitor of neuronal NO-synthase was more effective than the inhibitor of inducible NO-synthase in the experiments without adaptation to hypoxia. Markedly greater protective effect was achieved by the simultaneous introduction of inhibitors of neuronal and inducible NO-synthase. The greatest protective effect in the development of stress damage in rats of KM was observed in short-term adaptation to hypobaric hypoxia with simultaneous introduction of both inhibitors. Conclusions. It can be assumed that an excessive amount of NO produced by neuronal and inducible NO-synthases during the acoustic exposure in KM rats leads to stress damage. Use of selective inhibitors reduce the excess NO synthesis and the development of audiogenic stress damage caused by hemorrhagic stroke.

  14. Low toxic corrosion inhibitors for aluminum in fresh water

    NASA Technical Reports Server (NTRS)

    Humphries, T. S.

    1978-01-01

    Combinations of chemical compounds that reportedly reduce the corrosion of aluminum in fresh water were evaluated. These included combinations of borates, nitrates, nitrites, phosphates, silicates, and mercaptobenzothiazole. Eight of fifty inhibitor combinations evaluated gave excellent corrosion protection and compared favorably with sodium chromate, which has generally been considered standard for many years.

  15. Development of scale inhibitors

    SciTech Connect

    Gill, J.S.

    1996-12-01

    During the last fifty years, scale inhibition has gone from an art to a science. Scale inhibition has changed from simple pH adjustment to the use of optimized dose of designer polymers from multiple monomers. The water-treatment industry faces many challenges due to the need to conserve water, availability of only low quality water, increasing environmental regulations of the water discharge, and concern for human safety when using acid. Natural materials such as starch, lignin, tannin, etc., have been replaced with hydrolytically stable organic phosphates and synthetic polymers. Most progress in scale inhibition has come from the use of synergistic mixtures and copolymerizing different functionalities to achieve specific goals. Development of scale inhibitors requires an understanding of the mechanism of crystal growth and its inhibition. This paper discusses the historic perspective of scale inhibition and the development of new inhibitors based on the understanding of the mechanism of crystal growth and the use of powerful tools like molecular modeling to visualize crystal-inhibitor interactions.

  16. Characterization of a novel Kazal-type serine proteinase inhibitor of Arabidopsis thaliana.

    PubMed

    Pariani, Sebastián; Contreras, Marisol; Rossi, Franco R; Sander, Valeria; Corigliano, Mariana G; Simón, Francisco; Busi, María V; Gomez-Casati, Diego F; Pieckenstain, Fernando L; Duschak, Vilma G; Clemente, Marina

    2016-04-01

    Many different types of serine proteinase inhibitors have been involved in several kinds of plant physiological processes, including defense mechanisms against phytopathogens. Kazal-type serine proteinase inhibitors, which are included in the serine proteinase inhibitor family, are present in several organisms. These proteins play a regulatory role in processes that involve serine proteinases like trypsin, chymotrypsin, thrombin, elastase and/or subtilisin. In the present work, we characterized two putative Kazal-type serine proteinase inhibitors from Arabidopsis thaliana, which have a single putative Kazal-type domain. The expression of these inhibitors is transiently induced in response to leaf infection by Botrytis cinerea, suggesting that they play some role in defense against pathogens. We also evaluated the inhibitory specificity of one of the Kazal-type serine proteinase inhibitors, which resulted to be induced during the local response to B. cinerea infection. The recombinant Kazal-type serine proteinase inhibitor displayed high specificity for elastase and subtilisin, but low specificity for trypsin, suggesting differences in its selectivity. In addition, this inhibitor exhibited a strong antifungal activity inhibiting the germination rate of B. cinerea conidia in vitro. Due to the important role of proteinase inhibitors in plant protection against pathogens and pests, the information about Kazal-type proteinase inhibitors described in the present work could contribute to improving current methods for plant protection against pathogens.

  17. The 5-Lipoxygenase Inhibitor Zileuton Confers Neuroprotection against Glutamate Oxidative Damage by Inhibiting Ferroptosis.

    PubMed

    Liu, Yang; Wang, Wei; Li, Yuyao; Xiao, Yunqi; Cheng, Jian; Jia, Jia

    2015-01-01

    5-Lipoxygenase (5-LOX) inhibitors have been shown to be protective in several neurodegenerative disease models; however, the underlying mechanisms remain unclear. We investigated whether 5-LOX inhibitor zileuton conferred direct neuroprotection against glutamate oxidative toxicity by inhibiting ferroptosis, a newly identified iron-dependent programmed cell death. Treatment of HT22 mouse neuronal cell line with glutamate resulted in significant cell death, which was inhibited by zileuton in a dose-dependent manner. Consistently, zileuton decreased glutamate-induced production of reactive oxygen species but did not restore glutamate-induced depletion of glutathione. Moreover, the pan-caspase inhibitor Z-Val-Ala-Asp(OMe)-fluoromethyl ketone (ZVAD-fmk) neither prevented HT22 cell death induced by glutamate nor affected zileuton protection against glutamate oxidative toxicity, suggesting that zileuton did not confer neuroprotection by inhibiting caspase-dependent apoptosis. Interestingly, glutamate-induced HT22 cell death was significantly inhibited by the ferroptosis inhibitor ferrostatin-1. Moreover, zileuton protected HT22 neuronal cells from erastin-induced ferroptosis. However, we did not observe synergic protective effects of zileuton and ferrostatin-1 on glutamate-induced cell death. These results suggested that both the 5-LOX inhibitor zileuton and the ferropotosis inhibitor ferrostatin-1 acted through the same cascade to protect against glutamate oxidative toxicity. In conclusion, our results suggested that zileuton protected neurons from glutamate-induced oxidative stress at least in part by inhibiting ferroptosis.

  18. Noise Protection

    NASA Technical Reports Server (NTRS)

    1980-01-01

    Environmental Health Systems puts forth an increasing effort in the U.S. to develop ways of controlling noise, particularly in industrial environments due to Federal and State laws, labor union insistence and new findings relative to noise pollution impact on human health. NASA's Apollo guidance control system aided in the development of a noise protection product, SMART. The basis of all SMART products is SMART compound a liquid plastic mixture with exceptional energy/sound absorbing qualities. The basic compound was later refined for noise protection use.

  19. Structures protection

    NASA Technical Reports Server (NTRS)

    1977-01-01

    Materials of which an aircraft is made and the methods used to hold these materials together forming the aircraft structure were studied as factors important in protecting a modern aircraft from hazardous natural environments. Since all-metal aircraft are being replaced by aircraft constructed partly of fiber reinforced plastics with desirable light weight and high strength properties but with poor electrical conductivity, the danger of lightning strikes has become more serious. Lightning effects on metal structures were reviewed and design protection was discussed. The expected lightning effects on nonmetallic materials such as fiberglass and advanced composites were also reviewed.

  20. Ozone Layer Protection

    MedlinePlus

    ... EPA United States Environmental Protection Agency Search Search Ozone Layer Protection Share Facebook Twitter Google+ Pinterest Contact Us Ozone Layer Protection Welcome to EPA's ozone layer protection web ...

  1. Protective Clothing

    NASA Technical Reports Server (NTRS)

    1981-01-01

    Beta Glass material, originating from the Apollo program is supplied to Fyrepel by Owens-Corning and incorporated into Fyrepel's Fyretex and Beta-Mex aluminized fabrics. Fabrics are used in fire entry suits, several other types of protective suits for wear in hot industrial environments and such accessory items as heat-reflecting curtains for industrial applications.

  2. Characterization of Encapsulated Corrosion Inhibitors for Environmentally Friendly Smart Coatings

    NASA Technical Reports Server (NTRS)

    Pearman, B. P.; Calle, L. M.; Zhang, X.; Li, W.; Buhrow, J. W.; Johnsey, M. N.; Montgomery, E. L.; Fitzpatrick, L.; Surma, J. M.

    2015-01-01

    The NASA Kennedy Space Center's Corrosion Technology Lab at the Kennedy Space Center in Florida, U.S.A. has been developing multifunctional smart coatings based on the microencapsulation of environmentally friendly corrosion indicators, inhibitors and self-healing agents. This allows the incorporation of autonomous corrosion control functionalities, such as corrosion detection and inhibition as well as the self-healing of mechanical damage, into coatings. This paper presents technical details on the characterization of inhibitor-containing particles and their corrosion inhibitive effects using electrochemical and mass loss methods. Three organic environmentally friendly corrosion inhibitors were encapsulated in organic microparticles that are compatible with desired coatings. The release of the inhibitors from the microparticles in basic solution was studied. Fast release, for immediate corrosion protection, as well as long-term release for continued protection, was observed. The inhibition efficacy of the inhibitors, incorporated directly and in microparticles, on carbon steel was evaluated. Polarization curves and mass loss measurements showed that, in the case of 2MBT, its corrosion inhibition effectiveness was greater when it was delivered from microparticles.

  3. [Tyrosine kinase inhibitors].

    PubMed

    Robert, Jacques

    2011-11-01

    Membrane receptors with tyrosine kinase activity and cytoplasmic tyrosine kinases have emerged as important potential targets in oncology. Starting from basic structures such as anilino-quinazoline, numerous compounds have been synthesised, with the help of tyrosine kinase crystallography, which has allowed to optimise protein-ligand interactions. The catalytic domains of all kinases present similar three-dimensional structures, which explains that it may be difficult to identify molecules having a high specificity for a given tyrosine kinase. Some tyrosine kinase inhibitors are relatively specific for epidermal growth factor receptor (EGFR) such as géfitinib and erlotinib; other are mainly active against platelet-derived growth factor receptor (PDGFR) and the receptor KIT, such as imatinib or nilotinib, and other against vascular endothelial growth factor (VEGF) receptors involved in angiogenesis, such as sunitinib and sorafenib. The oral formulation of tyrosine kinase inhibitors is well accepted by the patients but may generate sometimes compliance problems requiring pharmacokinetic monitoring. This chemical family is in full expansion and several dozens of compounds have entered clinical trials.

  4. Phylogenetic distribution of protease inhibitors of the Kazal-family within the Arthropoda.

    PubMed

    van Hoef, Vincent; Breugelmans, Bert; Spit, Jornt; Simonet, Gert; Zels, Sven; Vanden Broeck, Jozef

    2013-03-01

    In mammalian pancreatic cells, the pancreatic secretory trypsin inhibitor (PSTI) belonging to the Kazal-family prevents the premature activation of digestive enzymes and thus plays an important role in a protective mechanism against tissue destruction by autophagy. Although a similar protective mechanism exists in Arthropoda, the distribution of these inhibitors in this phylum remains obscure. A comprehensive in silico search of nucleotide databases, revealed the presence of members of the Kazal-family in the four major subphyla of the Arthropoda. Especially in the Hexapoda and the Crustacea these inhibitors are widespread, while in the Chelicerata and Myriapoda only a few Kazal-like protease inhibitors were found. A sequence alignment of inhibitors retrieved in the digestive system of insects revealed a conservation of the PSTI characteristics and strong resemblance to vertebrate PSTI. A phylogenetic analysis of these inhibitors showed that they generally cluster according to their order. The results of this data mining study provide new evidence for the existence of an ancient protective mechanism in metazoan digestive systems. Kazal-like inhibitors, which play an important protective role in the pancreas of vertebrates, also seem to be present in Arthropoda.

  5. The evolution of renin-angiotensin blockade: angiotensin-converting enzyme inhibitors as the starting point.

    PubMed

    Sica, Domenic A

    2010-04-01

    The renin-angiotensin system has been a target in the treatment of hypertension for close to three decades. Several medication classes that block specific aspects of this system have emerged as useful therapies, including angiotensin-converting enzyme inhibitors, angiotensin receptor blockers, and, most recently, direct renin inhibitors. There has been a natural history to the development of each of these three drug classes, starting with their use as antihypertensive agents; thereafter, in each case they have been employed as end-organ protective agents. To date, there has been scant evidence to favor angiotensin receptor blockers or direct renin inhibitors over angiotensin-converting enzyme inhibitors in treating hypertension or in affording end-organ protection; thus, angiotensin-converting enzyme inhibitors remain the standard of care when renin-angiotensin system blockade is warranted.

  6. Synthesis of Lysine Methyltransferase Inhibitors

    NASA Astrophysics Data System (ADS)

    Ye, Tao; Hui, Chunngai

    2015-07-01

    Lysine methyltransferase which catalyze methylation of histone and nonhistone proteins, play a crucial role in diverse biological processes and has emerged as a promising target for the development of various human diseases, including cancer, inflammation, and psychiatric disorders. However, inhibiting Lysine methyltransferases selectively has presented many challenges to medicinal chemists. During the past decade, lysine methyltransferase inhibitors covering many different structural classes have been designed and developed. In this review, we describe the development of selective, small-molecule inhibitors of lysine methyltransferases with an emphasis on their discovery and chemical synthesis. We highlight the current state of lysine methyltransferase inhibitors and discuss future directions and opportunities for lysine methyltransferase inhibitor discovery.

  7. Protective Coating

    NASA Technical Reports Server (NTRS)

    1984-01-01

    Inorganic Coatings, Inc.'s K-Zinc 531 protective coating is water-based non-toxic, non-flammable and has no organic emissions. High ratio silicate formula bonds to steel, and in 30 minutes, creates a very hard ceramic finish with superior adhesion and abrasion resistance. Improved technology allows application over a minimal commercial sandblast, fast drying in high humidity conditions and compatibility with both solvent and water-based topcoats. Coating is easy to apply and provides long term protection with a single application. Zinc rich coating with water-based potassium silicate binder offers cost advantages in materials, labor hours per application, and fewer applications over a given time span.

  8. Using combination therapy to override stromal-mediated chemoresistance in mutant FLT3-positive AML: Synergism between FLT3 inhibitors, dasatinib/multi-targeted inhibitors, and JAK inhibitors

    PubMed Central

    Weisberg, Ellen; Liu, Qingsong; Nelson, Erik; Kung, Andrew L.; Christie, Amanda L.; Bronson, Rod; Sattler, Martin; Sanda, Takaomi; Zhao, Zheng; Hur, Wooyoung; Mitsiades, Constantine; Smith, Robert; Daley, John F.; Stone, Richard; Galinsky, Ilene; Griffin, James D.; Gray, Nathanael

    2014-01-01

    Acute myeloid leukemia (AML) progenitors are frequently characterized by activating mutations in the receptor tyrosine kinase FLT3. Protein tyrosine kinases are integral components of signaling cascades that play a role in both FLT3-mediated transformation as well as viability pathways that are advantageous to leukemic cell survival. The bone marrow microenvironment can diminish AML sensitivity to tyrosine kinase inhibitors (TKIs). We hypothesized that inhibition of protein kinases in addition to FLT3 may be effective in overriding drug resistance in AML. We used a cell-based model mimicking stromal protection as part of an unbiased high-throughput chemical screen to identify kinase inhibitors with the potential to override microenvironment-mediated drug resistance in mutant FLT3-positive AML. Several related multi-targeted kinase inhibitors, including dasatinib, with the capability of reversing microenvironment-induced resistance to FLT3 inhibition were identified and validated. We validated synergy in vitro and demonstrated effective combination potential in vivo. In particular Janus kinase (JAK) inhibitors were effective in overriding stromal protection and potentiating FLT3 inhibition in primary AML and cell lines. These results hint at a novel concept of using combination therapy to override drug resistance in mutant FLT3-positive AML in the bone marrow niche and suppress or eradicate residual disease. PMID:22469781

  9. Sequencing of aromatase inhibitors

    PubMed Central

    Bertelli, G

    2005-01-01

    Since the development of the third-generation aromatase inhibitors (AIs), anastrozole, letrozole and exemestane, these agents have been the subject of intensive research to determine their optimal use in advanced breast cancer. Not only have they replaced progestins in second-line therapy and challenged the role of tamoxifen in first-line, but there is also evidence for a lack of cross-resistance between the steroidal and nonsteroidal AIs, meaning that they may be used in sequence to obtain prolonged clinical benefit. Many questions remain, however, as to the best sequence of the two types of AIs and of the other available agents, including tamoxifen and fulvestrant, in different patient groups. PMID:16100523

  10. Sirtuin activators and inhibitors

    PubMed Central

    Villalba, José M.; Alcaín, Francisco J.

    2012-01-01

    Sirtuins 1-7 (SIRT1-7) belong to the third class of deacetylase enzymes, which are dependent on NAD+ for activity. Sirtuins activity is linked to gene repression, metabolic control, apoptosis and cell survival, DNA repair, development, inflammation, neuroprotection and healthy aging. Because sirtuins modulation could have beneficial effects on human diseases there is a growing interest in the discovery of small molecules modifying their activity. We review here those compounds known to activate or inhibit sirtuins, discussing the data that support the use of sirtuin-based therapies. Almost all sirtuin activators have been described only for SIRT1. Resveratrol is a natural compound which activates SIRT1, and may help in the treatment or prevention of obesity, and in preventing tumorigenesis and the aging-related decline in heart function and neuronal loss. Due to its poor bioavailability, reformulated versions of resveratrol with improved bioavailability have been developed (resVida, Longevinex®, SRT501). Molecules that are structurally unrelated to resveratrol (SRT1720, SRT2104, SRT2379, among others) have been also developed to stimulate sirtuin activities more potently than resveratrol. Sirtuin inhibitors with a wide range of core structures have been identified for SIRT1, SIRT2, SIRT3 and SIRT5 (splitomicin, sirtinol, AGK2, cambinol, suramin, tenovin, salermide, among others). SIRT1 inhibition has been proposed in the treatment of cancer, immunodeficiency virus infections, Fragile X mental retardation syndrome and for preventing or treating parasitic diseases, whereas SIRT2 inhibitors might be useful for the treatment of cancer and neurodegenerative diseases. PMID:22730114

  11. Effect of the enzymatic inhibitor of Kunitz on the gastric lesions from reserpine, from phenylbutazone, from pyloric ligation and by restraint in the rat

    NASA Technical Reports Server (NTRS)

    Guerrin, F.; Demaille, A.; Merveille, P.; Bel, C.

    1980-01-01

    The protective effects of certain polypeptides on gastric ulcerations caused from reserpine and phenylbutazone in the rate were studied. It was found that the Kunitz enzymatic inhibitor exerts a protective action in regard to gastric lesions. However, the inhibitor did not change the development of Shay ulcers and stress ulcers from restraint.

  12. Biological abatement of cellulase inhibitors

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Bio-abatement uses a fungus to metabolize and remove fermentation inhibitors. To determine whether bio-abatement could alleviate enzyme inhibitor effects observed in biomass liquors after pretreatment, corn stover at 10% (w/v) solids was pretreated with either dilute acid or liquid hot water. The ...

  13. Authentic HIV-1 integrase inhibitors

    PubMed Central

    Liao, Chenzhong; Marchand, Christophe; Burke, Terrence R; Pommier, Yves; Nicklaus, Marc C

    2010-01-01

    HIV-1 integrase (IN) is indispensable for HIV-1 replication and has become a validated target for developing anti-AIDS agents. In two decades of development of IN inhibition-based anti-HIV therapeutics, a significant number of compounds were identified as IN inhibitors, but only some of them showed antiviral activity. This article reviews a number of patented HIV-1 IN inhibitors, especially those that possess high selectivity for the strand transfer reaction. These compounds generally have a polar coplanar moiety, which is assumed to chelate two magnesium ions in the binding site. Resistance to those compounds, when given to patients, can develop as a result of IN mutations. We refer to those compounds as authentic IN inhibitors. Continued drug development has so far delivered one authentic IN inhibitor to the market (raltegravir in 2007). Current and future attention will be focused on the development of novel authentic IN inhibitors with the goal of overcoming viral resistance. PMID:21426159

  14. Silica nanocontainers for active corrosion protection.

    PubMed

    Maia, Frederico; Tedim, João; Lisenkov, Aleksey D; Salak, Andrei N; Zheludkevich, Mikhail L; Ferreira, Mário G S

    2012-02-21

    Novel self-healing protective coatings with nanocontainers of corrosion inhibitors open new opportunities for long-term anticorrosion protection of different metallic materials. In this paper a new type of functional nanoreservoir based on silica nanocapsules (SiNC) synthesized and loaded with corrosion inhibitor 2-mercaptobenzothiazole (MBT) in a one-stage process is reported for the first time. Unlike conventional mesoporous silica nanoparticles, SiNC possess an empty core and shell with gradual mesoporosity, arising from the particular conditions of the synthetic route adopted, which confers significant loading capacity and allows prolonged and stimuli-triggered release of the inhibiting species. The kinetics of inhibitor release was studied at different pH values and concentrations of NaCl. The results show a clear dependence of the release profiles on corrosion relevant triggers such as pH and Cl(-) concentration. When SiNC loaded with MBT are dispersed in NaCl solution, there is a significant decrease of the corrosion activity on aluminium alloy 2024. More importantly, when SiNC-MBT is added to a conventional water-based coating formulation, the modified coating hampers corrosion activity at the metal interface, better than in the case of direct addition of corrosion inhibitor. Furthermore, self-healing is observed before and after artificially inflicting defects in the modified coatings. As a result, the developed nanocontainers show high potential to be used in new generation of active protective coatings.

  15. Silica nanocontainers for active corrosion protection

    NASA Astrophysics Data System (ADS)

    Maia, Frederico; Tedim, João; Lisenkov, Aleksey D.; Salak, Andrei N.; Zheludkevich, Mikhail L.; Ferreira, Mário G. S.

    2012-02-01

    Novel self-healing protective coatings with nanocontainers of corrosion inhibitors open new opportunities for long-term anticorrosion protection of different metallic materials. In this paper a new type of functional nanoreservoir based on silica nanocapsules (SiNC) synthesized and loaded with corrosion inhibitor 2-mercaptobenzothiazole (MBT) in a one-stage process is reported for the first time. Unlike conventional mesoporous silica nanoparticles, SiNC possess an empty core and shell with gradual mesoporosity, arising from the particular conditions of the synthetic route adopted, which confers significant loading capacity and allows prolonged and stimuli-triggered release of the inhibiting species. The kinetics of inhibitor release was studied at different pH values and concentrations of NaCl. The results show a clear dependence of the release profiles on corrosion relevant triggers such as pH and Cl- concentration. When SiNC loaded with MBT are dispersed in NaCl solution, there is a significant decrease of the corrosion activity on aluminium alloy 2024. More importantly, when SiNC-MBT is added to a conventional water-based coating formulation, the modified coating hampers corrosion activity at the metal interface, better than in the case of direct addition of corrosion inhibitor. Furthermore, self-healing is observed before and after artificially inflicting defects in the modified coatings. As a result, the developed nanocontainers show high potential to be used in new generation of active protective coatings.

  16. Protecting Antarctica

    NASA Astrophysics Data System (ADS)

    Carlowicz, Michael

    House Science Committee Chairman Robert Walker (R-Pa.) has introduced a bill into Congress to give the United States the legislative authority to implement the 1991 Environmental Protocol to the Antarctic Treaty. That protocol established rules and principles to shield the Antarctic environment from human spoilage—placing limits on the discharge of pollutants, protecting plant and animal life, and requiring environmental impact assessments before new activities and programs are launched. The protocol also forbids prospecting or developing of mineral resources except for scientific research.

  17. Cathodic protection

    SciTech Connect

    Pfalser, I.L.; Brannan, M.S.

    1991-08-20

    This patent describes a cathodic protection system for protecting a metallic structure in contact with the earth from corrosion. It comprises at least one electrically conductive member positioned in a borehole in the earth which is defined by an earthen sidewall: a quantity of a particulate mixture of a clay and a carbonaceous solid which at least partially fills the borehole around the at least one conductive member such that the mixture contacts the earthen sidewall and the at least one conductive member, wherein the mixture has a clay to carbonaceous solid weight ratio of at least about 0.1:1; means for applying a DC electrical voltage to the metallic structure and the at least one conductive member such that the metallic structure is at a negative polarity and the at least one conductive member is at a positive polarity, whereby a current is established between the metallic structure and the at least one conductive member through the earth and the mixture.

  18. Regulation of factor XIa activity by platelets and alpha 1-protease inhibitor.

    PubMed Central

    Walsh, P N; Sinha, D; Kueppers, F; Seaman, F S; Blankstein, K B

    1987-01-01

    We have studied the complex interrelationships between platelets, Factor XIa, alpha 1-protease inhibitor and Factor IX activation. Platelets were shown to secrete an inhibitor of Factor XIa, and to protect Factor XIa from inactivation in the presence of alpha 1-protease inhibitor and the secreted platelet inhibitor. This protection of Factor XIa did not arise from the binding of Factor XIa to platelets, the presence of high molecular weight kininogen, or the inactivation of alpha 1-protease inhibitor by platelets. The formation of a complex between alpha 1-protease inhibitor and the active-site-containing light chain of Factor XIa was inhibited by activated platelets and by platelet releasates, but not by high molecular weight kininogen. These results support the hypothesis that platelets can regulate Factor XIa-catalyzed Factor IX activation by secreting an inhibitor of Factor XIa that may act primarily outside the platelet microenvironment and by protecting Factor XIa from inhibition, thereby localizing Factor IX activation to the platelet plug. Images PMID:3500185

  19. Smart Coatings for Corrosion Protection

    NASA Technical Reports Server (NTRS)

    Calle, Luz Marina; Li, Wendy; Buhrow, Jerry W.; Johnsey, Marissa N.

    2016-01-01

    Nearly all metals and their alloys are subject to corrosion that causes them to lose their structural integrity or other critical functionality. It is essential to detect corrosion when it occurs, and preferably at its early stage, so that action can be taken to avoid structural damage or loss of function. Protective coatings are the most commonly used method of corrosion control. However, progressively stricter environmental regulations have resulted in the ban of many commercially available corrosion protective coatings due to the harmful effects of their solvents or corrosion inhibitors. This work concerns the development of a multifunctional, smart coating for the autonomous control of corrosion. This coating is being developed to have the inherent ability to detect the chemical changes associated with the onset of corrosion and respond autonomously to indicate it and control it.

  20. Anthrax lethal factor inhibitors as potential countermeasure of the infection.

    PubMed

    Kumar, B V S Suneel; Malik, Siddharth; Grandhi, Pradeep; Dayam, Raveendra; Sarma, J A R P

    2014-01-01

    Anthrax Lethal Factor (LF) is a zinc-dependent metalloprotease, one of the virulence factor of anthrax infection. Three forms of the anthrax infection have been identified: cutaneous (through skin), gastrointestinal (through alimentary tract), and pulmonary (by inhalation of spores). Anthrax toxin is composed of protective antigen (PA), lethal factor (LF), and edema factor (EF). Protective antigen mediates the entry of Lethal Factor/Edema Factor into the cytosol of host cells. Lethal factor (LF) inactivates mitogen-activated protein kinase kinase inducing cell death, and EF is an adenylyl cyclase impairing host defenses. In the past few years, extensive studies are undertaken to design inhibitors targeting LF. The current review focuses on the small molecule inhibitors targeting LF activity and its structure activity relationships (SAR).

  1. Histone Deacetylase Inhibitors Preserve Function in Aging Axons

    PubMed Central

    Baltan, Selva

    2012-01-01

    Aging increases the vulnerability of aging white matter to ischemic injury. Histone deacetylase (HDAC) inhibitors preserve young adult white matter structure and function during ischemia by conserving ATP and reducing excitotoxicity. In isolated optic nerve from 12 month old mice, deprived of oxygen and glucose, we show that pan- and Class I specific HDAC inhibitors promote functional recovery of axons. This protection correlates with preservation of axonal mitochondria. The cellular expression of HDAC 3, in the central nervous system (CNS) and HDAC 2 in optic nerve considerably changed with age expanding to more cytoplasmic domains from nuclear compartments suggesting that changes in glial cell protein acetylation may confer protection to aging axons. Our results indicate manipulation of HDAC activities in glial cells may have a universal potential for stroke therapy across age groups. PMID:23050648

  2. Protective Coatings

    NASA Technical Reports Server (NTRS)

    1980-01-01

    General Magnaplate Corporation's pharmaceutical machine is used in the industry for high speed pressing of pills and capsules. Machine is automatic system for molding glycerine suppositories. These machines are typical of many types of drug production and packaging equipment whose metal parts are treated with space spinoff coatings that promote general machine efficiency and contribute to compliance with stringent federal sanitation codes for pharmaceutical manufacture. Collectively known as "synergistic" coatings, these dry lubricants are bonded to a variety of metals to form an extremely hard slippery surface with long lasting self lubrication. The coatings offer multiple advantages; they cannot chip, peel or be rubbed off. They protect machine parts from corrosion and wear longer, lowering maintenance cost and reduce undesired heat caused by power-robbing friction.

  3. Protease inhibitors from several classes work synergistically against Callosobruchus maculatus.

    PubMed

    Amirhusin, Bahagiawati; Shade, Richard E; Koiwa, Hisashi; Hasegawa, Paul M; Bressan, Ray A; Murdock, Larry L; Zhu-Salzman, Keyan

    2007-07-01

    Targeting multiple digestive proteases may be more effective in insect pest control than inhibition of a single enzyme class. We therefore explored possible interactions of three antimetabolic protease inhibitors fed to cowpea bruchids in artificial diets, using a recombinant soybean cysteine protease inhibitor scN, an aspartic protease inhibitor pepstatin A, and soybean Kunitz trypsin inhibitor KI. scN and pepstatin, inhibiting major digestive cysteine and aspartic proteases, respectively, significantly prolonged the developmental time of cowpea bruchids individually. When combined, the anti-insect effect was synergistic, i.e., the toxicity of the mixture was markedly greater than that of scN or pepstatin alone. KI alone did not impact insect development even at relatively high concentrations, but its anti-insect properties became apparent when acting jointly with scN or scN plus pepstatin. Incubating KI with bruchid midgut extract showed that it was partially degraded. This instability may explain its lack of anti-insect activity. However, this proteolytic degradation was inhibited by scN and/or pepstatin. Protection of KI from proteolysis in the insect digestive tract thus could be the basis for the synergistic effect. These observations support the concept that cowpea bruchid gut proteases play a dual role; digesting protein for nutrient needs and protecting insects by inactivating dietary proteins that may otherwise be toxic. Our results also suggest that transgenic resistance strategies that involve multigene products are likely to have enhanced efficacy and durability.

  4. Bitter gourd proteinase inhibitors: potential growth inhibitors of Helicoverpa armigera and Spodoptera litura.

    PubMed

    Telang, Manasi; Srinivasan, Ajay; Patankar, Aparna; Harsulkar, Abhay; Joshi, Vijay; Damle, Archana; Deshpande, Vasanti; Sainani, Mohini; Ranjekar, Prabhakar; Gupta, Gorakh; Birah, Ajanta; Rani, Seema; Kachole, Manavendra; Giri, Ashok; Gupta, Vidya

    2003-07-01

    Proteinase inhibitors (PIs) from the seeds of bitter gourd (Momordica charantia L.) were identified as strong inhibitors of Helicoverpa armigera gut proteinases (HGP). Biochemical investigations showed that bitter gourd PIs (BGPIs) inhibited more than 80% HGP activity. Electrophoretic analysis revealed the presence of two major proteins (BGPI-1 and-2) and two minor proteins (BGPI-3 and-4) having inhibitory activity against both trypsin and HGP. The major isoforms BGPI-1 and BGPI-2 have molecular mass of 3.5 and 3.0 kDa, respectively. BGPIs inhibited HGP activity of larvae fed on different host plants, on artificial diet with or without added PIs and proteinases excreted in fecal matter. Degradation of BGPI-1 by HGP showed direct correlation with accumulation of BGPI-2-like peptide, which remained stable and active against high concentrations of HGP up to 3 h. Chemical inhibitors of serine proteinases offered partial protection to BGPI-1 from degradation by HGP, suggesting that trypsin and chymotrypsin like proteinases are involved in degradation of BGPI-1. In larval feeding studies, BGPIs were found to retard growth and development of two lepidopteran pests namely Helicoverpa armigera and Spodoptera litura. This is the first report showing that BGPIs mediated inhibition of insect gut proteinases directly affects fertility and fecundity of both H. armigera and S. litura. The results advocate use of BGPIs to introduce insect resistance in otherwise susceptible plants.

  5. Protease inhibitors, part 13: Specific, weakly basic thrombin inhibitors incorporating sulfonyl dicyandiamide moieties in their structure.

    PubMed

    Clare, B W; Scozzafava, A; Supuran, C T

    2001-01-01

    A series of compounds has been prepared by reaction of dicyandiamide with alkyl/arylsulfonyl halides as well as arylsulfonylisocyanates to locate a lead for obtaining weakly basic thrombin inhibitors with sulfonyldicyandiamide moieties as the S1 anchoring group. The detected lead was sulfanilyl-dicyandiamide (K1 of 3 microM against thrombin, and 15 microM against trypsin), which has been further derivatized at the 4-amino group by incorporating arylsulfonylureido as well as amino acyl/dipeptidyl groups protected at the amino terminal moiety with benzyloxycarbonyl or tosylureido moieties. The best compound obtained (ts-D-Phe-Pro-sulfanilyl-dicyandiamide) showed inhibition constants of 9 nM against thrombin and 1400 nM against trypsin. pKa measurements showed that the new derivatives reported here do indeed possess a reduced basicity, with the pKa of the modified guanidine moieties in the range 7.9-8.3 pKa units. Molecular mechanics calculations showed that the preferred tautomeric form of these compounds is of the type ArSO2N=C(NH2) NH-CN, probably allowing for the formation of favorable interaction between this new anchoring group and the active site amino acid residue Asp 189, critical for substrate/inhibitor binding to this type of serine protease. Thus, the main finding of the present paper is that the sulfonyldicyandiamide group may constitute an interesting alternative for obtaining weakly basic, potent thrombin inhibitors, which bind with less affinity to trypsin.

  6. Sildenafil and Phosphodiesterase-5 Inhibitors to Reduce Cardiotoxicity and Enhance the Response of Breast Tumors to Doxorubicin

    DTIC Science & Technology

    2007-03-01

    AD_________________ Award Number: W81XWH-06-1-0360 TITLE: Sildenafil and phosphodiesterase-5...Feb 2007 4. TITLE AND SUBTITLE 5a. CONTRACT NUMBER Sildenafil and phosphodiesterase-5 inhibitors to reduce cardiotoxicity and enhance the...the differential effects of phosphodiesterase inhibitors, such as sildenafil , in terms of protecting cardiac cells and the heart from the toxicity

  7. Protection against malonate-induced ischemic brain injury in rat by a cell-permeable peptidic c-Jun N-terminal kinase inhibitor, (L)-HIV-TAT48-57-PP-JBD20, observed by the apparent diffusion coefficient mapping magnetic resonance imaging method.

    PubMed

    Asanuma, Taketoshi; Inanami, Osamu; Tabu, Kouichi; Waki, Kenji; Kon, Yasuhiro; Kuwabara, Mikinori

    2004-04-08

    The present experiments were carried out to provide direct in vivo evidence for the involvement of c-Jun N-terminal kinase (JNK) in the induction of ischemic brain injury. Malonate, which produces lesions similar to those of focal ischemia-reperfusion by a reversible inhibition of succinate dehydrogenase in mitochondria, was injected into the left striatum in the rat brain without or with the simultaneous injection of a cell permeable peptidic JNK inhibitor, (L)-HIV-TAT48-57-PP-JBD20. Two regions of malonate-induced brain injury were visualized as a hyperintense region with surrounding hypointense regions by apparent diffusion coefficient mapping magnetic resonance imaging. The JNK inhibitor significantly counteracted both hyper- and hypointense regions at the early stage of brain injury. Histological examination clarified that the inhibitor suppressed the induction of coagulation necrosis and spongy degeneration at early and late stages.

  8. A novel molluscicide, corrosion inhibitor, and dispersant

    SciTech Connect

    Kreuser, R.T.; Vanlaer, A.; Damour, A.

    1997-12-01

    The efficacy of filming amines as corrosion inhibitors and dispersants in steam systems is well-documented. A novel formulation retains these functions of traditional filming amines and adds molluscicide capability for controlling macrofouling in fresh water and sea water. Criteria for this development included low toxicity to mammals and to non-target aquatic species, rapid biodegradation, and multifunctionality. Low mammalian toxicity and lack of other hazards exempt it from reporting requirements under SARA Title 3. Toxicity (LC{sub 50}) levels for rainbow trout and fathead minnow are higher than typical dosage rates. Biodegradation is rapid; half life is 22 hours in river water. By effectively dispersing slimes (along with biofilm, scale, and tubercles), it controls slimes without toxicity to biofilm organisms. As corrosion inhibitor, it reduces the open cell potential of metal surfaces by 50--200 millivolts and retards pitting and crevice corrosion. Its molluscicide activity gradually kills and disperses mussels, clams, and barnacles. The protective film, renewed by dosage for a brief period of time each day, proactively prevents scale and slime deposits and repels settling and adhesion by macrofouling species. Refinement of established technology has produced a multi-functional formulation that is safe to handle and has minimal impact on the environment.

  9. Selective Inhibitors of Protein Methyltransferases

    PubMed Central

    2015-01-01

    Mounting evidence suggests that protein methyltransferases (PMTs), which catalyze methylation of histone and nonhistone proteins, play a crucial role in diverse biological processes and human diseases. In particular, PMTs have been recognized as major players in regulating gene expression and chromatin state. PMTs are divided into two categories: protein lysine methyltransferases (PKMTs) and protein arginine methyltransferases (PRMTs). There has been a steadily growing interest in these enzymes as potential therapeutic targets and therefore discovery of PMT inhibitors has also been pursued increasingly over the past decade. Here, we present a perspective on selective, small-molecule inhibitors of PMTs with an emphasis on their discovery, characterization, and applicability as chemical tools for deciphering the target PMTs’ physiological functions and involvement in human diseases. We highlight the current state of PMT inhibitors and discuss future directions and opportunities for PMT inhibitor discovery. PMID:25406853

  10. Inhibitors of pig kidney trehalase.

    PubMed

    Kyosseva, S V; Kyossev, Z N; Elbein, A D

    1995-02-01

    Trehazolin, a new trehalase inhibitor isolated from the culture broth of Micromonospora, was reported to be a highly specific inhibitor for porcine and silk worm trehalases with IC50 values of 5.5 x 10(-9) and 3.7 x 10(-9) M, respectively (O. Ando, H. Satake, K. Itoi, A. Sato, M. Nakajima, S. Takashi, H. Haruyama, Y. Ohkuma, T. Kinoshita, and R. Enokita (1991) J. Antibiot. 44, 1165-1168). We also found that trehazolin is a very powerful and quite specific inhibitor against purified pig kidney trehalase, giving an IC50 value of 1.9 x 10(-8) M. Lineweaver-Burk plots showed that this compound was a competitive inhibitor of the trehalase. However, even at concentrations of 200 micrograms/ml, trehazolin did not inhibit the rat intestinal maltase or sucrase, yeast alpha-glucosidase or almond beta-glucosidase. Validoxylamine A and validamycin A, two other trehalase inhibitors, showed potent competitive inhibition against purified pig kidney trehalase, with IC50 values of 2.4 x 10(-9) and 2.5 x 10(-4) M, respectively. On the other hand, validoxylamine A was almost inactive against rat intestinal sucrase and maltase, with some inhibition being observed at millimolar concentration. A number of other glucosidase inhibitors, such as MDL 25637, castanospermine, and deoxynojirimycin were also tested against the purified trehalase and showed reasonable inhibitory activity.

  11. Protecting Information

    NASA Astrophysics Data System (ADS)

    Loepp, Susan; Wootters, William K.

    2006-09-01

    For many everyday transmissions, it is essential to protect digital information from noise or eavesdropping. This undergraduate introduction to error correction and cryptography is unique in devoting several chapters to quantum cryptography and quantum computing, thus providing a context in which ideas from mathematics and physics meet. By covering such topics as Shor's quantum factoring algorithm, this text informs the reader about current thinking in quantum information theory and encourages an appreciation of the connections between mathematics and science.Of particular interest are the potential impacts of quantum physics:(i) a quantum computer, if built, could crack our currently used public-key cryptosystems; and (ii) quantum cryptography promises to provide an alternative to these cryptosystems, basing its security on the laws of nature rather than on computational complexity. No prior knowledge of quantum mechanics is assumed, but students should have a basic knowledge of complex numbers, vectors, and matrices. Accessible to readers familiar with matrix algebra, vector spaces and complex numbers First undergraduate text to cover cryptography, error-correction, and quantum computation together Features exercises designed to enhance understanding, including a number of computational problems, available from www.cambridge.org/9780521534765

  12. Endogenous antioxidant enzymes and glutathione S-transferase in protection of mesothelioma cells against hydrogen peroxide and epirubicin toxicity.

    PubMed Central

    Kinnula, K.; Linnainmaa, K.; Raivio, K. O.; Kinnula, V. L.

    1998-01-01

    We have previously shown that cultured malignant mesothelioma cells contain elevated manganese superoxide dismutase (MnSOD) mRNA levels and activities compared with non-malignant mesothelial cells. As many cytotoxic drugs generate both superoxide and hydrogen peroxide, we assessed the relative significance of catalase and the glutathione redox cycle, as well as glutathione S-transferase (GST), in protecting these cells against hydrogen peroxide and epirubicin toxicity. Mesothelioma cell lines containing high (M38K cells) and low (M14K cells) MnSOD, and non-malignant MeT-5A mesothelial cells were selected for the study. M38K cells were the most resistant of these three cell types to hydrogen peroxide (0.1-0.5 mM, 4 h) and epirubicin (0.1-0.5 microg ml(-1), 48 h) as judged by lactate dehydrogenase (LDH) release and by high-energy nucleotide (ATP, ADP, AMP) depletion. Total glutathione was higher in M38K cells (63.8 +/- 20.3 nnmol mg(-1) protein) than in M14K (25.2 +/- 8.2 nmol mg[-1]) or MeT-5A cells (23.5 +/- 4.5 nmol mg[-1]). Furthermore, GST specific activity was higher in M38K cells (111.3 +/- 15.8 U mg[-1]) than in M14K cells (77.4 +/- 6.6 U mg[-1]) or in MeT-5A cells (68.8 +/- 7.6 U mg[-1]). Western blotting indicated the presence of GST-pi in all these cells, the reactivity again being highest in M38K cells. Depletion of glutathione by buthionine sulphoximine and inhibition of catalase by aminotriazole enhanced hydrogen peroxide toxicity in all cell types, while only the depletion of glutathione increased epirubicin toxicity. We conclude that simultaneous induction of multiple antioxidant enzymes can occur in human mesothelioma cells. In addition to the high MnSOD activity, hydrogen peroxide scavenging antioxidant enzymes, glutathione and GST can partly explain the high hydrogen peroxide and epirubicin resistance of these cells in vitro. Images Figure 4 PMID:9569045

  13. A Culture-Based Method for Determining the Production of Secreted Protease Inhibitors

    PubMed Central

    Quintero, David; Bermudes, David

    2014-01-01

    We have developed a culture-based method for determining the production of secreted protease inhibitors. The assay utilizes standard proteolysis detection plates to support microbial growth followed by infiltrating the plate with a protease and subsequently detecting the remaining protein by trichloroacetic acid (TCA) precipitation, or by bromocreosol green (BCG) or Ponseau S (PS) staining. The presence of a protease inhibitor can be observed in the form of a protected zone of protein around the protease inhibitor-producing strain. Using the protease inhibitors α-2-macroglobulin, aprotinin, leupeptin, and bestatin and the primary and secondary forms of Photorhabdus luminescens in combination with the protease trypsin, we were able to demonstrate that the assay is specific for the cognate inhibitor of the protease and for bacteria secreting protease inhibitors. In addition, when casein-containing plates were used, the size of the diffusion zone was inversely correlated with the molecular weight of the inhibitor allowing a relative estimation of the protease inhibitor molecular weight. This assay is useful for detecting the presence of microbial secreted protease inhibitors and may reveal their production by microorganisms that were not previously recognized to produce them. PMID:24632514

  14. C-Glucopyranosyl-1,2,4-triazoles As New Potent Inhibitors of Glycogen Phosphorylase

    PubMed Central

    2013-01-01

    Glycogen phosphorylase inhibitors are considered as potential antidiabetic agents. 3-(β-d-Glucopyranosyl)-5-substituted-1,2,4-triazoles were prepared by acylation of O-perbenzoylated N1-tosyl-C-β-d-glucopyranosyl formamidrazone and subsequent removal of the protecting groups. The best inhibitor was 3-(β-d-glucopyranosyl)-5-(2-naphthyl)-1,2,4-triazole (Ki = 0.41 μM against rabbit muscle glycogen phosphorylase b). PMID:24900719

  15. Engineering trypsin for inhibitor resistance.

    PubMed

    Batt, Anna R; St Germain, Commodore P; Gokey, Trevor; Guliaev, Anton B; Baird, Teaster

    2015-09-01

    The development of effective protease therapeutics requires that the proteases be more resistant to naturally occurring inhibitors while maintaining catalytic activity. A key step in developing inhibitor resistance is the identification of key residues in protease-inhibitor interaction. Given that majority of the protease therapeutics currently in use are trypsin-fold, trypsin itself serves as an ideal model for studying protease-inhibitor interaction. To test the importance of several trypsin-inhibitor interactions on the prime-side binding interface, we created four trypsin single variants Y39A, Y39F, K60A, and K60V and report biochemical sensitivity against bovine pancreatic trypsin inhibitor (BPTI) and M84R ecotin. All variants retained catalytic activity against small, commercially available peptide substrates [kcat /KM  = (1.2 ± 0.3) × 10(7) M(-1 ) s(-1) . Compared with wild-type, the K60A and K60V variants showed increased sensitivity to BPTI but less sensitivity to ecotin. The Y39A variant was less sensitive to BPTI and ecotin while the Y39F variant was more sensitive to both. The relative binding free energies between BPTI complexes with WT, Y39F, and Y39A were calculated based on 3.5 µs combined explicit solvent molecular dynamics simulations. The BPTI:Y39F complex resulted in the lowest binding energy, while BPTI:Y39A resulted in the highest. Simulations of Y39F revealed increased conformational rearrangement of F39, which allowed formation of a new hydrogen bond between BPTI R17 and H40 of the variant. All together, these data suggest that positions 39 and 60 are key for inhibitor binding to trypsin, and likely more trypsin-fold proteases.

  16. Natural Corrosion Inhibitors for Steel Reinforcement in Concrete — a Review

    NASA Astrophysics Data System (ADS)

    Raja, Pandian Bothi; Ghoreishiamiri, Seyedmojtaba; Ismail, Mohammad

    2015-04-01

    Reinforced concrete is one of the widely used construction materials for bridges, buildings, platforms and tunnels. Though reinforced concrete is capable of withstanding a large range of severe environments including marine, industrial and alpine conditions, there are still a large number of failures in concrete structures for many reasons. Either carbonation or chloride attack is the main culprit which is due to depassivation of reinforced steel and subsequently leads to rapid steel corrosion. Among many corrosion prevention measures, application of corrosion inhibitors play a vital role in metal protection. Numerous range of corrosion inhibitors were reported for concrete protection that were also used commercially in industries. This review summarizes the application of natural products as corrosion inhibitors for concrete protection and also scrutinizes various factors influencing its applicability.

  17. Eco-Friendly Inhibitors for Copper Corrosion in Nitric Acid: Experimental and Theoretical Evaluation

    NASA Astrophysics Data System (ADS)

    Savita; Mourya, Punita; Chaubey, Namrata; Singh, V. K.; Singh, M. M.

    2016-02-01

    The inhibitive performance of Vitex negundo, Adhatoda vasica, and Saraka asoka leaf extracts on corrosion of copper in 3M HNO3 solution was investigated using gravimetric, potentiodynamic polarization, and electrochemical impedance spectroscopic techniques. Potentiodynamic polarization studies indicated that these extracts act as efficient and predominantly cathodic mixed inhibitor. Thermodynamic parameters revealed that the adsorption of these inhibitors on copper surface was spontaneous, controlled by physiochemical processes and occurred according to the Langmuir adsorption isotherm. AFM examination of copper surface confirmed that the inhibitor prevented corrosion by forming protective layer on its surface. The correlation between inhibitive effect and molecular structure was ascertained by density functional theory data.

  18. On the protection of "protected areas".

    PubMed

    Joppa, Lucas N; Loarie, Scott R; Pimm, Stuart L

    2008-05-06

    Tropical moist forests contain the majority of terrestrial species. Human actions destroy between 1 and 2 million km(2) of such forests per decade, with concomitant carbon release into the atmosphere. Within these forests, protected areas are the principle defense against forest loss and species extinctions. Four regions-the Amazon, Congo, South American Atlantic Coast, and West Africa-once constituted about half the world's tropical moist forest. We measure forest cover at progressively larger distances inside and outside of protected areas within these four regions, using datasets on protected areas and land-cover. We find important geographical differences. In the Amazon and Congo, protected areas are generally large and retain high levels of forest cover, as do their surroundings. These areas are protected de facto by being inaccessible and will likely remain protected if they continue to be so. Deciding whether they are also protected de jure-that is, whether effective laws also protect them-is statistically difficult, for there are few controls. In contrast, protected areas in the Atlantic Coast forest and West Africa show sharp boundaries in forest cover at their edges. This effective protection of forest cover is partially offset by their very small size: little area is deep inside protected area boundaries. Lands outside protected areas in the Atlantic Coast forest are unusually fragmented. Finally, we ask whether global databases on protected areas are biased toward highly protected areas and ignore "paper parks." Analysis of a Brazilian database does not support this presumption.

  19. Synthesis of the proteinase inhibitor LEKTI domain 6 by the fragment condensation method and regioselective disulfide bond formation.

    PubMed

    Vasileiou, Zoe; Barlos, Kostas K; Gatos, Dimitrios; Adermann, Knut; Deraison, Celine; Barlos, Kleomenis

    2010-01-01

    Proteinase inhibitors are of high pharmaceutical interest and are drug candidates for a variety of indications. Specific kallikrein inhibitors are important for their antitumor activity and their potential application to the treatment of skin diseases. In this study we describe the synthesis of domain 6 of the kallikrein inhibitor Lympho-Epithilial Kazal-Type Inhibitor (LEKTI) by the fragment condensation method and site-directed cystine bridge formation. To obtain the linear LEKTI precursor, the condensation was best performed in solution, coupling the protected fragment 1-22 to 23-68. This method yielded LEKTI domain 6 of high purity and equipotent to the recombinantly produced peptide.

  20. Protease inhibitor in scorpion (Mesobuthus eupeus) venom prolongs the biological activities of the crude venom.

    PubMed

    Ma, Hakim; Xiao-Peng, Tang; Yang, Shi-Long; Lu, Qiu-Min; Lai, Ren

    2016-08-01

    It is hypothesized that protease inhibitors play an essential role in survival of venomous animals through protecting peptide/protein toxins from degradation by proteases in their prey or predators. However, the biological function of protease inhibitors in scorpion venoms remains unknown. In the present study, a trypsin inhibitor was purified and characterized from the venom of scorpion Mesobuthus eupeus, which enhanced the biological activities of crude venom components in mice when injected in combination with crude venom. This protease inhibitor, named MeKTT-1, belonged to Kunitz-type toxins subfamily. Native MeKTT-1 selectively inhibited trypsin with a Kivalue of 130 nmol·L(-1). Furthermore, MeKTT-1 was shown to be a thermo-stable peptide. In animal behavioral tests, MeKTT-1 prolonged the pain behavior induced by scorpion crude venom, suggesting that protease inhibitors in scorpion venom inhibited proteases and protect the functionally important peptide/protein toxins from degradation, consequently keeping them active longer. In conclusion, this was the first experimental evidence about the natural existence of serine protease inhibitor in the venom of scorpion Mesobuthus eupeus, which preserved the activity of venom components, suggests that scorpions may use protease inhibitors for survival.

  1. Release Properties and Electrochemical Characterization of Encapsulated Corrosion Inhibitors for Environmentally Friendly Smart Coatings

    NASA Technical Reports Server (NTRS)

    Pearman, B. P.; Calle, L. M.; Zhang, X.; Li, W.; Buhrow, J. W.; Johnsey, M. N.; Montgomery, E. L.; Fitzpatrick, L.; Surma, J. M.

    2015-01-01

    The NASA Kennedy Space Center's Corrosion Technology Lab at the Kennedy Space Center in Florida, U.S.A. has been developing multifunctional smart coatings based on the microencapsulation of environmentally friendly corrosion indicators, inhibitors and self-healing agents. This allows for the incorporation of autonomous corrosion control functionalities, such as corrosion detection and inhibition as well as the self-healing of mechanical damage, into coatings. This paper presents technical details on the characterization of inhibitor-containing particles and their corrosion inhibitive effects using electrochemical and mass loss methods. Three organic environmentally friendly corrosion inhibitors were encapsulated in organic microparticles that are compatible with desired coatings. The total inhibitor content and the release of one of the inhibitors from the microparticles in basic solution was measured. Particles with inhibitor contents of up 60 wt% were synthesized. Fast release, for immediate corrosion protection, as well as long-term release for continued protection, was observed. The inhibition efficacy of the inhibitors, both as the pure materials and in microparticles, on carbon steel was evaluated. Polarization curves and mass loss measurements showed that, in the case of 2MBT, its corrosion inhibition effectiveness was greater when it was delivered from microparticles.

  2. [New anticoagulants - direct thrombin inhibitors].

    PubMed

    Brand, B; Graf, L

    2012-11-01

    Direct thrombin-inhibitors inactivate not only free but also fibrin-bound thrombin. The group of parenteral direct thrombin-inhibitors includes the recombinant hirudins lepirudin and desirudin, the synthetic hirudin bivalirudin, and the small molecule argatroban. All these compounds do not interact with PF4/heparin-antibodies. Therefore, argatroban as well as bivalirudin are currently used to treat heparin-induced thrombocytopenia (HIT). The oral direct thrombin-inhibitor dabigatran etexilate is already licensed in many countries for the treatment of non-valvular atrial fibrillation. Dabigatran etexilate reveals a stable and predictable effect that allows a medication without dose adjustment or monitoring. The substance shows only few interactions with other drugs but strong inhibitors of p-glycoprotein can increase plasma levels of dabigatran substantially. After oral intake, the prodrug dabigatran etexilate is cleaved by esterase-mediated hydrolyses to the active compound dabigatran. Elimination of dabigatran is predominantly renal. Safety and efficacy of dabigatran etexilate were tested in an extensive clinical study program. Non-inferiority compared to current standard treatments was shown for prophylaxis of venous thromboembolic events after total knee and hip replacement, for stroke prevention in atrial fibrillation, and for treatment of acute venous thromboembolism. In daily practice, Dabigatran etexilate competes against the new direct factor Xa-inhibitors. In the absence of direct comparative clinical trials, it is not yet clear if one class of substances has distinct advantages over the other.

  3. Corrosion inhibitors from expired drugs.

    PubMed

    Vaszilcsin, Nicolae; Ordodi, Valentin; Borza, Alexandra

    2012-07-15

    This paper presents a method of expired or unused drugs valorization as corrosion inhibitors for metals in various media. Cyclic voltammograms were drawn on platinum in order to assess the stability of pharmaceutically active substances from drugs at the metal-corrosive environment interface. Tafel slope method was used to determine corrosion rates of steel in the absence and presence of inhibitors. Expired Carbamazepine and Paracetamol tablets were used to obtain corrosion inhibitors. For the former, the corrosion inhibition of carbon steel in 0.1 mol L(-1) sulfuric acid solution was about 90%, whereas for the latter, the corrosion inhibition efficiency of the same material in the 0.25 mol L(-1) acetic acid-0.25 mol L(-1) sodium acetate buffer solution was about 85%.

  4. Electrochemical studies of corrosion inhibitors

    NASA Technical Reports Server (NTRS)

    Danford, M. D.

    1990-01-01

    The effect of single salts, as well as multicomponent mixtures, on corrosion inhibition was studied for type 1010 steel; for 5052, 1100, and 2219-T87 aluminum alloys; and for copper. Molybdate-containing inhibitors exhibit an immediate, positive effect for steel corrosion, but an incubation period may be required for aluminum before the effect of a given inhibitor can be determined. The absence of oxygen was found to provide a positive effect (smaller corrosion rate) for steel and copper, but a negative effect for aluminum. This is attributed to the two possible mechanisms by which aluminum can oxidize. Corrosion inhibition is generally similar for oxygen-rich and oxygen-free environments. The results show that the electrochemical method is an effective means of screening inhibitors for the corrosion of single metals, with caution to be exercised in the case of aluminum.

  5. Positron emitter labeled enzyme inhibitors

    DOEpatents

    Fowler, Joanna S.; MacGregor, Robert R.; Wolf, Alfred P.; Langstrom, Bengt

    1990-01-01

    This invention involves a new strategy for imaging and mapping enzyme activity in the living human and animal body using positron emitter-labeled suicide enzyme inactivators or inhibitors which become covalently bound to the enzyme as a result of enzymatic catalysis. Two such suicide inactivators for monoamine oxidase have been labeled with carbon-11 and used to map the enzyme subtypes in the living human and animal body using PET. By using positron emission tomography to image the distribution of radioactivity produced by the body penetrating radiation emitted by carbon-11, a map of functionally active monoamine oxidase activity is obtained. Clorgyline and L-deprenyl are suicide enzyme inhibitors and irreversibly inhibit monoamine oxidase. When these inhibitors are labeled with carbon-11 they provide selective probes for monoamine oxidase localization and reactivity in vivo using positron emission tomography.

  6. An environmentally friendly scale inhibitor

    SciTech Connect

    Dobbs, J.B.; Brown, J.M.

    1999-11-01

    This paper describes a method of inhibiting the formation of scales such as barium and strontium sulfate in low pH aqueous systems, and calcium carbonate in systems containing high concentrations of dissolved iron. The solution, chemically, involves treating the aqueous system with an inhibitor designed to replace organic-phosphonates. Typical low pH aqueous systems where the inhibitor is particularly useful are oilfield produced-water, resin bed water softeners that form scale during low pH, acid regeneration operations. Downhole applications are recommended where high concentrations of dissolved iron are present in the produced water. This new approach to inhibition replaces typical organic phosphonates and polymers with a non-toxic, biodegradable scale inhibitor that performs in harsh environments.

  7. Positron emitter labeled enzyme inhibitors

    SciTech Connect

    Fowler, J.S.; MacGregor, R.R.; Wolf, A.P.; Langstrom, B.

    1990-04-03

    This invention involves a new strategy for imaging and mapping enzyme activity in the living human and animal body using positron emitter-labeled suicide enzyme inactivators or inhibitors which become covalently bound to the enzyme as a result of enzymatic catalysis. Two such suicide inactivators for monoamine oxidase have been labeled with carbon-11 and used to map the enzyme subtypes in the living human and animal body using PET. By using positron emission tomography to image the distribution of radioactivity produced by the body penetrating radiation emitted by carbon-11, a map of functionally active monoamine oxidase activity is obtained. Clorgyline and L-deprenyl are suicide enzyme inhibitors and irreversibly inhibit monoamine oxidase. When these inhibitors are labeled with carbon-11 they provide selective probes for monoamine oxidase localization and reactivity in vivo using positron emission tomography.

  8. Positron emitter labeled enzyme inhibitors

    DOEpatents

    Fowler, J.S.; MacGregor, R.R.; Wolf, A.P.

    1987-05-22

    This invention involved a new strategy for imaging and mapping enzyme activity in the living human and animal body using positron emitter-labeled suicide enzyme inactivators or inhibitors which become covalently bound to the enzyme as a result of enzymatic catalysis. Two such suicide in activators for monoamine oxidase have been labeled with carbon-11 and used to map the enzyme subtypes in the living human and animal body using PET. By using positron emission tomography to image the distribution of radioactivity produced by the body penetrating radiation emitted by carbon-11, a map of functionally active monoamine oxidase activity is obtained. Clorgyline and L-deprenyl are suicide enzyme inhibitors and irreversibly inhibit monoamine oxidase. When these inhibitors are labeled with carbon-11 they provide selective probes for monoamine oxidase localization and reactivity in vivo using positron emission tomography. 2 figs.

  9. STAT inhibitors for cancer therapy

    PubMed Central

    2013-01-01

    Signal Transducer and Activator of Transcription (STAT) proteins are a family of cytoplasmic transcription factors consisting of 7 members, STAT1 to STAT6, including STAT5a and STAT5b. STAT proteins are thought to be ideal targets for anti-cancer therapy since cancer cells are more dependent on the STAT activity than their normal counterparts. Inhibitors targeting STAT3 and STAT5 have been developed. These included peptidomimetics, small molecule inhibitors and oligonucleotides. This review summarized advances in preclinical and clinical development of these compounds. PMID:24308725

  10. [Kinase inhibitors against hematological malignancies].

    PubMed

    Tojo, Arinobu

    2014-06-01

    Dysregulation of protein phosphorylation, especially on tyrosine residues, plays a crucial role in development and progression of hematological malignancies. Since remarkable success in imatinib therapy of CML and Ph+ALL, extensive efforts have made to explore candidate molecular targets and next breakthrough drugs. Now that next generation ABL kinase inhibitors are available for CML, the therapeutic algorithm has been revolutionized. As for AML and lymphoid malignancies, many kinase inhibitors targeting FLT3, BTK and aurora-A are on early and late clinical trials, and a number of promising drugs including ibrutinib are picked up for further evaluation.

  11. Occupant Protection Project

    NASA Technical Reports Server (NTRS)

    Bopp, Genie; Somers, Jeff; Granderson, Brad; Gernhardt, Mike; Currie, Nancy; Lawrence, Chuck

    2010-01-01

    Topics include occupant protection overview with a focus on crew protection during dynamic phases of flight; occupant protection collaboration; modeling occupant protection; occupant protection considerations; project approach encompassing analysis tools, injury criteria, and testing program development; injury criteria update methodology, unique effects of pressure suits and other factors; and a summary.

  12. EGFR inhibitors and autophagy in cancer treatment.

    PubMed

    Cui, Jie; Hu, Yun-Feng; Feng, Xie-Min; Tian, Tao; Guo, Ya-Huan; Ma, Jun-Wei; Nan, Ke-Jun; Zhang, Hong-Yi

    2014-12-01

    Epidermal growth factor receptor (EGFR) inhibitor treatment is a strategy for cancer therapy. However, innate and acquired resistance is a major obstacle of the efficacy. Autophagy is a self-digesting process in cells, which is considered to be associated with anti-cancer drug resistance. The activation of EGFR can regulate autophagy through multiple signal pathways. EGFR inhibitors can induce autophagy, but the specific function of the induction of autophagy by EGFR inhibitors remains biphasic. On the one hand, autophagy induced by EGFR inhibitors acts as a cytoprotective response in cancer cells, and autophagy inhibitors can enhance the cytotoxic effects of EGFR inhibitors. On the other hand, a high level of autophagy after treatment of EGFR inhibitors can also result in autophagic cell death lacking features of apoptosis, and the combination of EGFR inhibitors with an autophagy inducer might be beneficial. Thus, autophagy regulation represents a promising approach for improving the efficacy of EGFR inhibitors in the treatment of cancer patients.

  13. Analysis of Different Inhibitors for Magnesium Investment Casting

    NASA Astrophysics Data System (ADS)

    Herrero-Dorca, N.; Sarriegi Etxeberria, H.; Hurtado, I.; Andres, U.; Rodriguez, P.; Arruebarrena, G.

    2012-01-01

    Investment casting of magnesium is a well suited process for the production of aeronautic and automotive components. But still, this process has not been properly developed. One reason for that are the reactions between the Mg melt and the ceramics of the mould that produce a non-desired oxide layer on the part surface. These reactions can be inhibited by the use of silica-free slurries with a higher stability than conventional ones. Another way is using inhibitors, chemical compounds based in fluorides that react with the melt, creating a protective surface layer in the casting. With the aim of developing a reaction-free process, alumina moulds with a stepped geometry have been constructed. These provide different interface conditions. Conventional SF6, non-conventional KBF4 and NaBF4 and environmentally friendly FK inhibitors have been tested on. As a result, KBF4 has been identified as the most suitable inhibitor for magnesium investment casting. Furthermore, the analysis of the cooling curve of different interfaces has provided essential information about the reaction mechanism of the inhibitors.

  14. Calcium pentosan polysulfate is a multifaceted exosite inhibitor of aggrecanases.

    PubMed

    Troeberg, Linda; Fushimi, Kazunari; Khokha, Rama; Emonard, Hervé; Ghosh, Peter; Nagase, Hideaki

    2008-10-01

    Degradation of the cartilage proteoglycan aggrecan is a key early event in the development of osteoarthritis. Adamalysin with thrombospondin motifs (ADAMTS) -4 and ADAMTS-5 are considered to be the main enzymes responsible for aggrecan breakdown, making them attractive drugs targets. Here we show that calcium pentosan polysulfate (CaPPS), a chemically sulfated xylanopyranose from beechwood, is a multifaceted exosite inhibitor of the aggrecanases and protects cartilage against aggrecan degradation. CaPPS interacts with the noncatalytic spacer domain of ADAMTS-4 and the cysteine-rich domain of ADAMTS-5, blocking activity against their natural substrate aggrecan with inhibitory concentration 50 values of 10-40 nM but only weakly inhibiting hydrolysis of a nonglycosylated recombinant protein substrate. In addition, CaPPS increased cartilage levels of tissue inhibitor of metalloproteinases-3 (TIMP-3), an endogenous inhibitor of ADAMTS-4 and -5. This was due to the ability of CaPPS to block endocytosis of TIMP-3 mediated by low-density lipoprotein receptor-related protein. CaPPS also increased the affinity of TIMP-3 for ADAMTS-4 and -5 by more than 100-fold, improving the efficacy of TIMP-3 as an aggrecanase inhibitor. Studies with TIMP-3-null mouse cartilage indicated that CaPPS inhibition of aggrecan degradation is TIMP-3 dependent. These unique properties make CaPPS a prototypic disease-modifying agent for osteoarthritis.

  15. Selective indole-based ECE inhibitors: synthesis and pharmacological evaluation.

    PubMed

    Brands, Michael; Ergüden, Jens-Kerim; Hashimoto, Kentaro; Heimbach, Dirk; Krahn, Thomas; Schröder, Christian; Siegel, Stephan; Stasch, Johannes-Peter; Tsujishita, Hideki; Weigand, Stefan; Yoshida, Nagahiro H

    2006-01-01

    Inhibition of the metalloprotease ECE-1 may be beneficial for the treatment of coronary heart disease, cancer, renal failure, and urological disorders. A novel class of indole-based ECE inhibitors was identified by high throughput screening. Optimization of the original screening lead structure 6 led to highly potent inhibitors such as 11, which bears a bisaryl amide moiety linked to the indole C2 position through an amide group. Docking of 11 into a model structure of ECE revealed a unique binding mode in which the Zn center of the enzyme is not directly addressed by the inhibitor, but key interactions are suggested for the central amide group. Testing of the lead compound 6 in hypertensive Dahl S rats resulted in a decrease in blood pressure after an initial period in which the blood pressure remained unchanged, most probably the result of ET-1 already present. Indole derivative 6 also displays a cardio-protective effect in a mouse model of acute myocardial infarction after oral administration. The more potent chloropyridine derivative 9 antagonizes big-ET-1-induced increase in blood pressure in rats at intravenous administration of 3 mg kg-1. All ECE inhibitors of the indole class showed high selectivity for ECE over related metalloproteases such as NEP and ACE. Therefore, these compounds might have further potential as drugs for the treatment of coronary heart diseases.

  16. Cardio-renal protection with empagliflozin

    PubMed Central

    Jerums, George; Ekinci, Elif I.

    2016-01-01

    Cardiovascular (CV) and kidney disease are common and significant complications in people with type 2 diabetes (T2DM). CV disease is the leading cause of death, morbidly and hospitalisations for people with T2DM. Furthermore, diabetic kidney disease is a major risk factor for CV disease and is the main reason why patients need renal replacement therapy. In this perspective, we highlight the results of the recent landmark EMPA-REG OUTCOME trial which has shown that empagliflozin, a member of the sodium-glucose co-transporter 2 (SGLT-2) inhibitor class of glucose lowering medications, reduces death from CV causes, hospitalisation for heart failure and progression to end stage kidney disease in patients with T2DM and established CV disease. The SGLT2 receptor mediates high-capacity glucose uptake in the early proximal tubule, and SGLT2 inhibitors, via their ability to promote glycosuria, have been developed as glucose lowering medications. As well as having a glucose lowering effect, SGLT-2 inhibitors also reduce blood pressure, promote weight loss and reduce uric acid levels. Potential side-effects or concerns related to the use of SGLT-2 inhibitors include increased rates of urinary tract infections, genital tract infections, postural hypotension, diabetic ketoacidosis, acute kidney injury and possible increased rates of fractures. The exact mechanisms that result in empagliflozin’s dramatic CV and renal protective effects, with a very favourable safety/tolerability profile, in the EMPA-REG study remain to be fully defined. However, they are most likely distinct from the glucose lowering effects of empagliflozin. CV safety trials involving dapagliflozin and canagliflozin, members of the SGLT-2 class, are under way and the results from these studies will help to answer the question as to whether the cardio-renal benefits of empagliflozin are a class-effect or not. Without doubt, trials to investigate whether SGLT-2 inhibitors have cardio-renal protective effects in

  17. COMMUNITY BASED ENVIRONMENTAL PROTECTION

    EPA Science Inventory

    Community Based Environmental Protection intends to make environmental protection spring from the needs and values of the community of interest. Real community involvement in protecting the environment requires a process in which the environmental needs of communities and ecosyst...

  18. [Tumor angiogenesis inhibitors: media and scientific aspects].

    PubMed

    Raymond, E

    Work begun more than 30 years ago at Children's Hospital in Boston led to the publication of an article on the antiangiogenic properties of two compounds, endostatin and angiostatin (J. Folkman, Nature 1997; 390:404-7). It only took weeks for the medias in the US and then in France and the rest of Europe to stimulate the fervor of patients for this new 'cure' for cancer. Insight into the fundamental role of angiogenesis in locoregional and metastatic development of cancer has been accumulated over the last decades. Factors stimulating tumoral angiogenesis include aFGF, bFGF, VEGF, angiogenin, and other more recently discovered substances. Likewise, factors inhibiting tumoral angiogenesis, including angiostatin, have been identified. Angiostatin is a specific inhibitor of endothelial cell growth that migh appear rapidly in the serum of patients with a primary tumor. Angiostatin could have both local and systemic effects and possibly protect against metastatic dissemination in vivo. The importance of angiogenesis inhibitors was emphasized at the recent meeting of the American Association for Cancer Research (New Orleans March 28-April 1, 1998). To date, at least eleven compounds are being tested. Currently, most are in phase 1 or 2; for the few in phase 3, marketing approval will undoubtedly require several years. It is interesting to note that neither endostatin nor angiostatin are among the list of drugs under clinical assessment, first because these small human proteins are not available in sufficient quantity for therapeutic trials and secondly, because the processes necessary to produce pure and safe compounds remain to be developed. Even after these steps have been accomplished, preclinical evaluations will have to be performed before the first clinical trials could be envisaged. For the time being, antiangiogenesis remains a promising avenue of anti-cancer research but neither endostatin nor angiostatin will be available for human research for several months

  19. DNA-polymerase inhibitors. Rifamycin derivatives.

    PubMed Central

    Frolova, L Y; Meldrays, Y A; Kochkina, L L; Giller, S A; Eremeyev, A V; Grayevskaya, N A; Kisselev, L L

    1977-01-01

    Ten new derivatives of the antibiotic rifamycin with variable side chains at position 3 were synthesized. The inhibitory activity of these derivatives against DNA-polymerases isolated from avian myeloblastosis virus, E. coli and calf thymus were studied at various conditions. 3-(2,4,6-trinitrophenylhydrazone-(methyl) rifamycin SV is a strong inhibitor for all the polymerases tested and belongs to the C class inhibitors of reverse transcriptase. 3-(monoallylhydrazone-(methyl) rifamycin SV possesses a selective action on polymerases: at 0.1 mg/ml concentration it almost completely inhibits the reverse transcriptase and less than half of the bacterial and eukaryotic enzymes. A drug is found which strongly inhibits the DNA-polymerases from E. coli and calf thymus and weakly the viral enzyme. The inhibitory effect on reverse transcriptase is independent of the choice of template-primer; it could be overcome by the addition of excess enzyme but not of excess template-primer; the inhibition could be completely reversed by dilution of the drug-enzyme mixture. From Lineweaver-Burk analysis, the inhibition is noncompetitive with respect to the template-primer and, thus the drugs bind to the site different from the active site for the template-primer. From protective action of the template-primer and other data it might be suggested that the rifamycin derivatives act at an early step(s) in DNA synthesis catalyzed by reverse transcriptase. The obtained data are in agreement with the results for other derivatives of rifamycin SV described in literature. PMID:68462

  20. Acetylcholinesterase Inhibitors: Pharmacology and Toxicology

    PubMed Central

    Čolović, Mirjana B; Krstić, Danijela Z; Lazarević-Pašti, Tamara D; Bondžić, Aleksandra M; Vasić, Vesna M

    2013-01-01

    Acetylcholinesterase is involved in the termination of impulse transmission by rapid hydrolysis of the neurotransmitter acetylcholine in numerous cholinergic pathways in the central and peripheral nervous systems. The enzyme inactivation, induced by various inhibitors, leads to acetylcholine accumulation, hyperstimulation of nicotinic and muscarinic receptors, and disrupted neurotransmission. Hence, acetylcholinesterase inhibitors, interacting with the enzyme as their primary target, are applied as relevant drugs and toxins. This review presents an overview of toxicology and pharmacology of reversible and irreversible acetylcholinesterase inactivating compounds. In the case of reversible inhibitors being commonly applied in neurodegenerative disorders treatment, special attention is paid to currently approved drugs (donepezil, rivastigmine and galantamine) in the pharmacotherapy of Alzheimer’s disease, and toxic carbamates used as pesticides. Subsequently, mechanism of irreversible acetylcholinesterase inhibition induced by organophosphorus compounds (insecticides and nerve agents), and their specific and nonspecific toxic effects are described, as well as irreversible inhibitors having pharmacological implementation. In addition, the pharmacological treatment of intoxication caused by organophosphates is presented, with emphasis on oxime reactivators of the inhibited enzyme activity administering as causal drugs after the poisoning. Besides, organophosphorus and carbamate insecticides can be detoxified in mammals through enzymatic hydrolysis before they reach targets in the nervous system. Carboxylesterases most effectively decompose carbamates, whereas the most successful route of organophosphates detoxification is their degradation by corresponding phosphotriesterases. PMID:24179466

  1. Benzimidazole derivatives as kinase inhibitors.

    PubMed

    Garuti, Laura; Roberti, Marinella; Bottegoni, Giovanni

    2014-01-01

    Benzimidazole is a common kinase inhibitor scaffold and benzimidazole-based compounds interact with enzymes by multiple binding modes. In some cases, the benzimidazole acts as part of the hinge-binding motif, in others it has a scaffolding role without evidence for direct hinge binding. Several of these compounds are ATP-competitive inhibitors and show high selectivity by exploiting unique structural properties that distinguish one kinase from the majority of other kinases. However, the high specificity for a single target is not always sufficient. Thus another approach, called multi-target therapy, has been developed over the last few years. The simultaneous inhibition of various kinases may be useful because the disease is attacked at several relevant targets. Moreover, if a kinase becomes drug-resistant, a multitargeted drug can act on the other kinases. Some benzimidazole derivatives are multi-target inhibitors. In this article benzimidazole inhibitors are reported with their mechanisms of action, structure-activity relationship (SAR) and biological properties.

  2. Biocatalysts with enhanced inhibitor tolerance

    DOEpatents

    Yang, Shihui; Linger, Jeffrey; Franden, Mary Ann; Pienkos, Philip T.; Zhang, Min

    2015-12-08

    Disclosed herein are biocatalysts for the production of biofuels, including microorganisms that contain genetic modifications conferring tolerance to growth and fermentation inhibitors found in many cellulosic feedstocks. Methods of converting cellulose-containing materials to fuels and chemicals, as well as methods of fermenting sugars to fuels and chemicals, using these biocatalysts are also disclosed.

  3. Azidoblebbistatin, a photoreactive myosin inhibitor

    PubMed Central

    Képiró, Miklós; Várkuti, Boglárka H.; Bodor, Andrea; Hegyi, György; Drahos, László; Kovács, Mihály; Málnási-Csizmadia, András

    2012-01-01

    Photoreactive compounds are important tools in life sciences that allow precisely timed covalent crosslinking of ligands and targets. Using a unique technique we have synthesized azidoblebbistatin, which is a derivative of blebbistatin, the most widely used myosin inhibitor. Without UV irradiation azidoblebbistatin exhibits identical inhibitory properties to those of blebbistatin. Using UV irradiation, azidoblebbistatin can be covalently crosslinked to myosin, which greatly enhances its in vitro and in vivo effectiveness. Photo-crosslinking also eliminates limitations associated with the relatively low myosin affinity and water solubility of blebbistatin. The wavelength used for photo-crosslinking is not toxic for cells and tissues, which confers a great advantage in in vivo tests. Because the crosslink results in an irreversible association of the inhibitor to myosin and the irradiation eliminates the residual activity of unbound inhibitor molecules, azidoblebbistatin has a great potential to become a highly effective tool in both structural studies of actomyosin contractility and the investigation of cellular and physiological functions of myosin II. We used azidoblebbistatin to identify previously unknown low-affinity targets of the inhibitor (EC50 ≥ 50 μM) in Dictyostelium discoideum, while the strongest interactant was found to be myosin II (EC50 = 5 μM). Our results demonstrate that azidoblebbistatin, and potentially other azidated drugs, can become highly useful tools for the identification of strong- and weak-binding cellular targets and the determination of the apparent binding affinities in in vivo conditions. PMID:22647605

  4. Inhibitor Discovery by Convolution ABPP.

    PubMed

    Chandrasekar, Balakumaran; Hong, Tram Ngoc; van der Hoorn, Renier A L

    2017-01-01

    Activity-based protein profiling (ABPP) has emerged as a powerful proteomic approach to study the active proteins in their native environment by using chemical probes that label active site residues in proteins. Traditionally, ABPP is classified as either comparative or competitive ABPP. In this protocol, we describe a simple method called convolution ABPP, which takes benefit from both the competitive and comparative ABPP. Convolution ABPP allows one to detect if a reduced signal observed during comparative ABPP could be due to the presence of inhibitors. In convolution ABPP, the proteomes are analyzed by comparing labeling intensities in two mixed proteomes that were labeled either before or after mixing. A reduction of labeling in the mix-and-label sample when compared to the label-and-mix sample indicates the presence of an inhibitor excess in one of the proteomes. This method is broadly applicable to detect inhibitors in proteomes against any proteome containing protein activities of interest. As a proof of concept, we applied convolution ABPP to analyze secreted proteomes from Pseudomonas syringae-infected Nicotiana benthamiana leaves to display the presence of a beta-galactosidase inhibitor.

  5. Protective Action Guides (PAGs)

    EPA Pesticide Factsheets

    The Protective Action Guide (PAG) manual contains radiation dose guidelines that would trigger public safety measures. EPA developed Protective Action Guides to help responders plan for radiation emergencies.

  6. Retro-inverso peptide inhibitor nanoparticles as potent inhibitors of aggregation of the Alzheimer's Aβ peptide.

    PubMed

    Gregori, Maria; Taylor, Mark; Salvati, Elisa; Re, Francesca; Mancini, Simona; Balducci, Claudia; Forloni, Gianluigi; Zambelli, Vanessa; Sesana, Silvia; Michael, Maria; Michail, Christos; Tinker-Mill, Claire; Kolosov, Oleg; Sherer, Michael; Harris, Stephen; Fullwood, Nigel J; Masserini, Massimo; Allsop, David

    2017-02-01

    Aggregation of amyloid-β peptide (Aβ) is a key event in the pathogenesis of Alzheimer's disease (AD). We investigated the effects of nanoliposomes decorated with the retro-inverso peptide RI-OR2-TAT (Ac-rGffvlkGrrrrqrrkkrGy-NH2) on the aggregation and toxicity of Aβ. Remarkably low concentrations of these peptide inhibitor nanoparticles (PINPs) were required to inhibit the formation of Aβ oligomers and fibrils in vitro, with 50% inhibition occurring at a molar ratio of ~1:2000 of liposome-bound RI-OR2-TAT to Aβ. PINPs also bound to Aβ with high affinity (Kd=13.2-50 nM), rescued SHSY-5Y cells from the toxic effect of pre-aggregated Aβ, crossed an in vitro blood-brain barrier model (hCMEC/D3 cell monolayer), entered the brains of C57 BL/6 mice, and protected against memory loss in APPSWE transgenic mice in a novel object recognition test. As the most potent aggregation inhibitor that we have tested so far, we propose to develop PINPs as a potential disease-modifying treatment for AD.

  7. Cathepsin D inhibitor from Vicia sativa L.

    PubMed

    Roszkowska-Jakimiec, W; Bańkowska, A

    1998-01-01

    Specific inhibitor of cathepsin D has been shown in the extract of Vicia sativa L. seeds. This inhibitor does not inhibit the activity of other aspartic proteases. Also it does not inhibit the activity of cysteine proteases and serine proteases.

  8. Improvement of the linear polarization resistance method for testing steel corrosion inhibitors

    NASA Astrophysics Data System (ADS)

    Faritov, A. T.; Rozhdestvenskii, Yu. G.; Yamshchikova, S. A.; Minnikhanova, E. R.; Tyusenkov, A. S.

    2016-11-01

    The linear polarization resistance method is used to improve the technique of corrosion control in liquid conducting according to GOST 9.514-99 (General Corrosion and Aging Protection System. Corrosion Inhibitors for Metals in Water Systems. Electrochemical Method of Determining the Protective Ability). Corrosion monitoring is shown to be performed by electronic devices with real-time data transfer to industrial controllers and SCADA systems.

  9. Products of the Black Sea alga Phyllophora nervosa as corrosion inhibitor for steel in acids

    SciTech Connect

    Popelyukh, G.M.; Andrianov, A.M.; Burtnenko, L.M.; Gazha, P.A.; Talavira, L.I.

    1986-05-01

    The authors have investigated the inhibiting properties of the processing products of the Black Sea red seaweed Phyllophora nervosa on specimens of steel St3 in phosphoric and hydrochloric acids of various concentrations at temperatures in the range from 30 to 95 /sup 0/C. They have studied how the concentrations of urotropin, sodium chloride, and Fe/sup 3 +/ ions influence the protective properties of the seaweed inhibitor. They have made preliminary investigations of the mechanisms of the protective action.

  10. The Wonders of Phosphodiesterase-5 Inhibitors: A Majestic History.

    PubMed

    Elhwuegi, A S

    2016-01-01

    The Nobel Prize winning discovery of nitric oxide (NO) in 1986 was the starting point for a new innovation in drug discovery. NO acting as a mediator at different physiological systems is believed to be involved in many physiological and pathological conditions through the formation of the second messenger cyclic guanosine monophosphate (cGMP). cGMP-dependent vasodilation effect of NO is important in regulating pulmonary and systemic pressures, maintaining penis erection, preventing atherosclerosis, preventing platelet aggregation, and protecting and controlling cardiac functions. The main enzyme involved in the termination of cGMP effects is phosphodiesterase enzyme 5 (PDE-5), which is overexpressed in ventricular hypertrophy and heart failure. A milestone in drug discovery was the selective inhibitors of PDE-5 that developed to be a multibillion dollar blockbuster in drug market. PDE-5 inhibitors are approved for the treatment of erectile dysfunctions (EDs), pulmonary hypertension, and benign prostatic hypertrophy. They are also under clinical trials for their cardiac protection against damage induced by ischemia or heart failure. This review article is an update about the pharmacotherapeutics of PDE-5 inhibitors and the majestic history that led to their discovery. The information reported in this review was obtained from the electronic sources of different databases such as PubMed Central, Google Scholar, and Scopus. Keywords used for search included cGMP (mechanisms and functions), EDs (drugs used), nitric oxide, and PDE-5 inhibitors (clinical applications). A total of 165 articles were studied, of which 45 articles were referred to in this review.

  11. The Wonders of Phosphodiesterase-5 Inhibitors: A Majestic History

    PubMed Central

    Elhwuegi, AS

    2016-01-01

    The Nobel Prize winning discovery of nitric oxide (NO) in 1986 was the starting point for a new innovation in drug discovery. NO acting as a mediator at different physiological systems is believed to be involved in many physiological and pathological conditions through the formation of the second messenger cyclic guanosine monophosphate (cGMP). cGMP-dependent vasodilation effect of NO is important in regulating pulmonary and systemic pressures, maintaining penis erection, preventing atherosclerosis, preventing platelet aggregation, and protecting and controlling cardiac functions. The main enzyme involved in the termination of cGMP effects is phosphodiesterase enzyme 5 (PDE-5), which is overexpressed in ventricular hypertrophy and heart failure. A milestone in drug discovery was the selective inhibitors of PDE-5 that developed to be a multibillion dollar blockbuster in drug market. PDE-5 inhibitors are approved for the treatment of erectile dysfunctions (EDs), pulmonary hypertension, and benign prostatic hypertrophy. They are also under clinical trials for their cardiac protection against damage induced by ischemia or heart failure. This review article is an update about the pharmacotherapeutics of PDE-5 inhibitors and the majestic history that led to their discovery. The information reported in this review was obtained from the electronic sources of different databases such as PubMed Central, Google Scholar, and Scopus. Keywords used for search included cGMP (mechanisms and functions), EDs (drugs used), nitric oxide, and PDE-5 inhibitors (clinical applications). A total of 165 articles were studied, of which 45 articles were referred to in this review. PMID:27398244

  12. Interfacial modification of clay nanotubes for the sustained release of corrosion inhibitors.

    PubMed

    Joshi, Anupam; Abdullayev, Elshad; Vasiliev, Alexandre; Volkova, Olga; Lvov, Yuri

    2013-06-18

    Long-lasting anticorrosive coatings for steel have been developed on the basis of halloysite nanotubes loaded with three corrosion inhibitors: benzotriazole, mercaptobenzothiazole, and mercaptobenzimidazole. The inhibitors' loaded tubes were admixed at 5-10 wt % to oil-based alkyd paint providing sustained agent release and corrosion healing in the coating defects. The slow 20-30 h release of the inhibitors at defect points caused a remarkable improvement in the anticorrosion efficiency of the coatings. Further time expansion of anticorrosion agent release has been achieved by the formation of release stoppers at nanotube ends with urea-formaldehyde copolymer and copper-inhibitor complexation. The corrosion protection efficiency was tested on ASTM A366 steel plates in a 0.5 M NaCl solution with the microscanning of corrosion current development by microscopy inspection and studying paint adhesion. The best protection was found using halloysite/mercaptobenzimidazole and benzotriazole inhibitors. Stopper formation with urea-formaldehyde copolymer provided an additional increase in corrosion efficiency as a result of the longer release of inhibitors.

  13. Characterization of Encapsulated Corrosion Inhibitors Containing Microparticles for Environmentally Friendly Smart Coatings

    NASA Technical Reports Server (NTRS)

    Pearman, Benjamin Pieter; Calle, Luz M.

    2015-01-01

    This poster presents the results obtained from experiments designed to evaluate the release properties, as well as the corrosion inhibition effectiveness, of several encapsulated corrosion inhibitors. Microencapsulation has been used in the development of environmentally friendly multifunctional smart coatings. This technique enables the incorporation of autonomous corrosion detection, inhibition and self-healing functionalities into many commercially available coating systems. Select environmentally friendly corrosion inhibitors were encapsulated in organic and inorganic pH-sensitive microparticles and their release in basic solutions was studied. The release rate results showed that the encapsulation can be tailored from fast, for immediate corrosion protection, to slow, which will provide continued long-term corrosion protection. The incorporation of several corrosion inhibitor release profiles into a coating provides effective corrosion protection properties. To investigate the corrosion inhibition efficiency of the encapsulated inhibitors, electrochemical techniques were used to obtain corrosion potential, polarization curve and polarization resistance data. These measurements were performed using the free as well as the encapsulated inhibitors singly or in combinations. Results from these electrochemical tests will be compared to those obtained from weight loss and other accelerated corrosion experiments.

  14. Inhibition of neuronal ferroptosis protects hemorrhagic brain

    PubMed Central

    Li, Qian; Han, Xiaoning; Lan, Xi; Gao, Yufeng; Wan, Jieru; Durham, Frederick; Cheng, Tian; Yang, Jie; Wang, Zhongyu; Jiang, Chao; Ying, Mingyao; Stockwell, Brent R.

    2017-01-01

    Intracerebral hemorrhage (ICH) causes high mortality and morbidity, but our knowledge of post-ICH neuronal death and related mechanisms is limited. In this study, we first demonstrated that ferroptosis, a newly identified form of cell death, occurs in the collagenase-induced ICH model in mice. We found that administration of ferrostatin-1, a specific inhibitor of ferroptosis, prevented neuronal death and reduced iron deposition induced by hemoglobin in organotypic hippocampal slice cultures (OHSCs). Mice treated with ferrostatin-1 after ICH exhibited marked brain protection and improved neurologic function. Additionally, we found that ferrostatin-1 reduced lipid reactive oxygen species production and attenuated the increased expression level of PTGS2 and its gene product cyclooxygenase-2 ex vivo and in vivo. Moreover, ferrostatin-1 in combination with other inhibitors that target different forms of cell death prevented hemoglobin-induced cell death in OHSCs and human induced pluripotent stem cell–derived neurons better than any inhibitor alone. These results indicate that ferroptosis contributes to neuronal death after ICH, that administration of ferrostatin-1 protects hemorrhagic brain, and that cyclooxygenase-2 could be a biomarker of ferroptosis. The insights gained from this study will advance our knowledge of the post-ICH cell death cascade and be essential for future preclinical studies.

  15. Inhibition of neuronal ferroptosis protects hemorrhagic brain.

    PubMed

    Li, Qian; Han, Xiaoning; Lan, Xi; Gao, Yufeng; Wan, Jieru; Durham, Frederick; Cheng, Tian; Yang, Jie; Wang, Zhongyu; Jiang, Chao; Ying, Mingyao; Koehler, Raymond C; Stockwell, Brent R; Wang, Jian

    2017-04-06

    Intracerebral hemorrhage (ICH) causes high mortality and morbidity, but our knowledge of post-ICH neuronal death and related mechanisms is limited. In this study, we first demonstrated that ferroptosis, a newly identified form of cell death, occurs in the collagenase-induced ICH model in mice. We found that administration of ferrostatin-1, a specific inhibitor of ferroptosis, prevented neuronal death and reduced iron deposition induced by hemoglobin in organotypic hippocampal slice cultures (OHSCs). Mice treated with ferrostatin-1 after ICH exhibited marked brain protection and improved neurologic function. Additionally, we found that ferrostatin-1 reduced lipid reactive oxygen species production and attenuated the increased expression level of PTGS2 and its gene product cyclooxygenase-2 ex vivo and in vivo. Moreover, ferrostatin-1 in combination with other inhibitors that target different forms of cell death prevented hemoglobin-induced cell death in OHSCs and human induced pluripotent stem cell-derived neurons better than any inhibitor alone. These results indicate that ferroptosis contributes to neuronal death after ICH, that administration of ferrostatin-1 protects hemorrhagic brain, and that cyclooxygenase-2 could be a biomarker of ferroptosis. The insights gained from this study will advance our knowledge of the post-ICH cell death cascade and be essential for future preclinical studies.

  16. Ebselen protects brain, skin, lung and blood cells from mechlorethamine toxicity.

    PubMed

    Hardej, Diane; Billack, Blase

    2007-05-01

    Nitrogen mustards are vesicants capable of burning the skin, eyes and respiratory tract of exposed individuals. While generally less toxic than sulfur mustards, these compounds have the potential for use as chemical warfare agents. Presently, no antidote exists for treatment against nitrogen mustard toxicity. The purpose of this study was to investigate the in vitro toxicity of the nitrogen mustard mechlorethamine (HN2) in four cell models: CEM-SS human T cells, A431 human skin epithelial cells, rat hippocampal astrocytes and rat pleural mesothelial cells. Furthermore, the efficacy of the synthetic seleno-organic compound ebselen (Eb) (2-phenyl-1,2- benzisoselenazol-3(2H)-one) as a cytoprotective agent against such toxicity was evaluated. Significant increases in cell viability, as assessed using an MTT assay for viability, was demonstrated when 30 microM Eb was used as a cotreatment with HN2 in all cell models tested at the following doses of HN2: A431 skin cells,10-40 microM; rat astrocytes, 20 and 40 microM; rat mesothelia, 10-40 microM; and human T cells 4-16 microM. Decreases in cell viability and toxicity to HN2 were confirmed using light and scanning electron microscopy. Membrane damage, observed with HN2 exposure, such as blebbing and loss of cell projections, was ameliorated with Eb cotreatment. Our results demonstrate a generalized protective effect observed with Eb cotreatment that suggests that this agent may have potential as an antidote for HN2 exposure and toxicity.

  17. Evaluating the Effects of CDK Inhibitors in Ischemia-Reperfusion Injury Models.

    PubMed

    Guevara, Tatiana

    2016-01-01

    CDK inhibitors have been used to induce protection in various experimental models. Kidney ischemia-reperfusion (I/R) is a form of acute kidney injury resulting in a cascade of cellular events prompting rapid cellular damage and suppression of kidney function. I/R injury, an inevitable impairment during renal transplant surgery, remains one of the major causes of acute kidney injury and represents the most prominent factor leading to delayed graft function after transplantation. Understanding the molecular events responsible for tubule damage and recovery would help to develop new strategies for organ preservation. This chapter describes procedures to study the effect of CDK inhibitors in the cellular I/R model developed from an epithelial cell line deriving from pig kidney proximal tubule cells (LLC-PK1). We briefly describe methods for determining the protective effect of CDK inhibitors such as activation of caspase 3/7, western blot analysis, gene silencing, and immunoprecipitation.

  18. Small-molecule arginase inhibitors.

    PubMed

    Ivanenkov, Yan A; Chufarova, Nina V

    2014-01-01

    Arginase is an enzyme that metabolizes L-arginine to L-ornithine and urea. In addition to its fundamental role in the hepatic ornithine cycle, it also influences the immune systems in humans and mice. Arginase participates in many inflammatory disorders by decreasing the synthesis of nitric oxide and inducing fibrosis and tissue regeneration. L-arginine deficiency, which is modulated by myeloid cell arginase, suppresses T-cell immune response. This mechanism plays a fundamental role in inflammation-associated immunosuppression. Pathogens can synthesize their own arginase to elude immune reaction. Small-molecule arginase inhibitors are currently described as promising therapeutics for the treatment of several diseases, including allergic asthma, inflammatory bowel disease, ulcerative colitis, cardiovascular diseases (atherosclerosis and hypertension), diseases associated with pathogens (e.g., Helicobacter pylori, Trypanosoma cruzi, Leishmania, Mycobacterium tuberculosis and Salmonella), cancer and induced or spontaneous immune disorders. This article summarizes recent patents in the area of arginase inhibitors and discusses their properties.

  19. Salicylanilide Inhibitors of Toxoplasma gondii

    PubMed Central

    Fomovska, Alina; Wood, Richard D.; Mui, Ernest; Dubey, Jitenter P.; Ferriera, Leandra R.; Hickman, Mark R.; Lee, Patricia J.; Leed, Susan E.; Auschwitz, Jennifer M.; Welsh, William J.; Sommerville, Caroline; Woods, Stuart; Roberts, Craig; McLeod, Rima

    2012-01-01

    Toxoplasma gondii(T. gondii) is an apicomplexan parasite that can cause eye disease, brain disease, and death, especially in congenitally infected and immune-compromised people. Novel medicines effective against both active and latent forms of the parasite are greatly needed. The current study focused on the discovery of such medicines by exploring a family of potential inhibitors whose anti-apicomplexan activity has not been previously reported. Initial screening efforts revealed that niclosamide, a drug approved for anthelmintic use, possessed promising activity in vitro against T. gondii. This observation inspired the evaluation of the activity of a series of salicylanilides and derivatives. Several inhibitors with activities in the nanomolar range with no appreciable in vitro toxicity to human cells were identified. An initial structure-activity relationship was explored. Four compounds were selected for evaluation in an in vivo model of infection, and two derivatives with potentially enhanced pharmacological parameters demonstrated the best activity profiles. PMID:22970937

  20. Salicylanilide inhibitors of Toxoplasma gondii.

    PubMed

    Fomovska, Alina; Wood, Richard D; Mui, Ernest; Dubey, Jitenter P; Ferreira, Leandra R; Hickman, Mark R; Lee, Patricia J; Leed, Susan E; Auschwitz, Jennifer M; Welsh, William J; Sommerville, Caroline; Woods, Stuart; Roberts, Craig; McLeod, Rima

    2012-10-11

    Toxoplasma gondii (T. gondii) is an apicomplexan parasite that can cause eye disease, brain disease, and death, especially in congenitally infected and immune-compromised people. Novel medicines effective against both active and latent forms of the parasite are greatly needed. The current study focused on the discovery of such medicines by exploring a family of potential inhibitors whose antiapicomplexan activity has not been previously reported. Initial screening efforts revealed that niclosamide, a drug approved for anthelmintic use, possessed promising activity in vitro against T. gondii. This observation inspired the evaluation of the activity of a series of salicylanilides and derivatives. Several inhibitors with activities in the nanomolar range with no appreciable in vitro toxicity to human cells were identified. An initial structure-activity relationship was explored. Four compounds were selected for evaluation in an in vivo model of infection, and two derivatives with potentially enhanced pharmacological parameters demonstrated the best activity profiles.

  1. Extending the cellulosome paradigm: the modular Clostridium thermocellum cellulosomal serpin PinA is a broad-spectrum inhibitor of subtilisin-like proteases.

    PubMed

    O Cuív, Páraic; Gupta, Rajesh; Goswami, Hareshwar P; Morrison, Mark

    2013-10-01

    Clostridium thermocellum encodes a cellulosomal, modular, and thermostable serine protease inhibitor (serpin), PinA. PinA stability but not inhibitory activity is affected by the Fn(III) and Doc(I) domains, and PinA is a broad inhibitor of subtilisin-like proteases and may play a key role in protecting the cellulosome from protease attack.

  2. Synthesis of 5-ethynyl-2'-deoxyuridine-5'-boranomono phosphate as a potential thymidylate synthase inhibitor.

    PubMed

    Khan, Shoeb I; Dobrikov, Mikhail I; Shaw, Barbara Ramsay

    2005-01-01

    The 5-ethynyl-2'-deoxyuridine nucleoside and the 5'-boranomonophosphate nucleotide were synthesized as analogs of 5-fluoro-2'-deoxyuridine monophosphate (5-FdUMP), a widely used mechanism-based inhibitor of thymidylate synthase. Synthesis was carried out from protected 5-iodo-2'-deoxyuridine and trimethylsilylacetylene by Sonogashira palladium-catalyzed cross coupling reaction followed by selective phosphorylation and finally boronation.

  3. Recent progress on fucosyltransferase inhibitors.

    PubMed

    Merino, Pedro; Tejero, Tomás; Delso, Ignacio; Hurtado-Guerrero, Ramon; Gómez-SanJuan, Asier; Sádaba, David

    2012-12-01

    Fucosyltransferases (FucTs) are enzymes that transfer L-fucose from GDP-fucose to a glycoside or a peptide. They have important roles in a variety of diseases including cancer and autoimmune disorders, viral and bacterial infections and inflammatory processes, and thus they represent important drug targets for the development of agents for the treatment of such disorders. This review highlights recent developments regarding carbohydrate mimics as inhibitors of FucTs. The most recent and relevant synthetic strategies are described.

  4. Nelfinavir: fourth protease inhibitor approved.

    PubMed

    1997-01-01

    The Food and Drug Administration (FDA) has granted accelerated approval to nelfinavir in both adult and pediatric formulations. Agouron, the manufacturer, used innovative computerized drug design techniques to discover, design, and refine the nelfinavir molecule. Nelfinavir is marketed under the trade name Viracept, and costs $5,000 per year. Early clinical trials find it to be as powerful as the other protease inhibitors, but with a different resistance profile. The drug has relatively few drug indications; however, several compounds have been contraindicated.

  5. Voglibose: An Alpha Glucosidase Inhibitor

    PubMed Central

    Dabhi, Ajay S.; Bhatt, Nikita R.; Shah, Mohit J.

    2013-01-01

    Diabetes Mellitus (DM) is a morbid disease worldwide, with increasing incidence as time passes. It has macro-vascular and micro-vascular complications. The main cause of these complications is poorly controlled postprandial hyperglycaemia. Alpha glucosidase inhibitors, namely acarbose, voglibose and miglitol, are available for therapy. Voglibose is well tolerated and effective in comparable doses among these drugs. This article highlights the important features of voglibose. PMID:24551718

  6. Kinase Inhibitors from Marine Sponges

    PubMed Central

    Skropeta, Danielle; Pastro, Natalie; Zivanovic, Ana

    2011-01-01

    Protein kinases play a critical role in cell regulation and their deregulation is a contributing factor in an increasing list of diseases including cancer. Marine sponges have yielded over 70 novel compounds to date that exhibit significant inhibitory activity towards a range of protein kinases. These compounds, which belong to diverse structural classes, are reviewed herein, and ordered based upon the kinase that they inhibit. Relevant synthetic studies on the marine natural product kinase inhibitors have also been included. PMID:22073013

  7. Evaluation of corrosion inhibitor for low-pH ammonium nitrate-methanol completion fluid

    SciTech Connect

    Krilov, Z.; Soric, T.; Tomic, M.; Wojtanowicz, A.K.

    1997-02-01

    A specially formulated completion fluid, low-pH ammonium nitrate-methanol-water mixture (ANM), compatible with argillaceous and calcareous Adriatic Sea sandstone formations, appears to be very corrosive for steel wellbore equipment. More than 12 commercially available, as well as some originally formulated, chemical additives were laboratory tested at room temperature using weight-loss and electrochemical methods to find an effective corrosion inhibitor for ANM. Two inhibitors, a commercially available, organic, amine base (OA) and an originally formulated, inorganic, ammonium dihydrogen phosphate base (IB), showed effective protection of carbon steel in contact with ANM fluid (corrosion rate was less than 5 mil/yr). Both selected corrosion inhibitors did not exhibit any additional rock permeability impairment during fluid-rock compatibility flow tests if ANM fluid was filtered before injection into the core samples. For inorganic inhibitor IB, additional filtration of inhibited fluid is not required.

  8. Field trials for corrosion inhibitor selection and optimization, using a new generation of electrical resistance probes

    SciTech Connect

    Ridd, B.; Blakset, T.J.; Queen, D.

    1998-12-31

    Even with today`s availability of corrosion resistant alloys, carbon steels protected by corrosion inhibitors still dominate the material selection for pipework in the oil and gas production. Even though laboratory screening tests of corrosion inhibitor performance provides valuable data, the real performance of the chemical can only be studied through field trials which provide the ultimate test to evaluate the effectiveness of an inhibitor under actual operating conditions. A new generation of electrical resistance probe has been developed, allowing highly sensitive and immediate response to changes in corrosion rates on the internal environment of production pipework. Because of the high sensitivity, the probe responds to small changes in the corrosion rate, and it provides the corrosion engineer with a highly effective method of optimizing the use of inhibitor chemicals resulting in confidence in corrosion control and minimizing detrimental environmental effects.

  9. Carbonic anhydrase inhibitors drug design.

    PubMed

    McKenna, Robert; Supuran, Claudiu T

    2014-01-01

    Inhibition of the metalloenzyme carbonic anhydrase (CA, EC 4.2.1.1) has pharmacologic applications in the field of antiglaucoma, anticonvulsant, antiobesity, and anticancer agents but is also emerging for designing anti-infectives (antifungal and antibacterial agents) with a novel mechanism of action. As a consequence, the drug design of CA inhibitors (CAIs) is a very dynamic field. Sulfonamides and their isosteres (sulfamates/sulfamides) constitute the main class of CAIs which bind to the metal ion in the enzyme active site. Recently the dithiocarbamates, possessing a similar mechanism of action, were reported as a new class of inhibitors. Other families of CAIs possess a distinct mechanism of action: phenols, polyamines, some carboxylates, and sulfocoumarins anchor to the zinc-coordinated water molecule. Coumarins and five/six-membered lactones are prodrug inhibitors, binding in hydrolyzed form at the entrance of the active site cavity. Novel drug design strategies have been reported principally based on the tail approach for obtaining all these types of CAIs, which exploit more external binding regions within the enzyme active site (in addition to coordination to the metal ion), leading thus to isoform-selective compounds. Sugar-based tails as well as click chemistry were the most fruitful developments of the tail approach. Promising compounds that inhibit CAs from bacterial and fungal pathogens, of the dithiocarbamate, phenol and carboxylate types have also been reported.

  10. Substituted androstanes as aromatase inhibitors

    NASA Astrophysics Data System (ADS)

    Levina, Inna S.

    1998-11-01

    The synthesis and structure-activity relationships of inhibitors of steroid aromatase which catalyses the last stage of a multistep biotransformation of cholesterol into estrogens, viz., aromatisation of C19-steroids into C18-phenolic steroids, are discussed. Compounds of the androstane series which are structurally related to the natural substrate, viz., androst-4-ene-3,17-dione, are the subjects of consideration. The review encompasses problems of synthesis of various substituted androstanes and their aromatase-inhibiting activities and structural requirements for selective specific aromatase inhibitors based on in vitro and in vivo structure-activity studies of compounds synthesised, their biological properties and the results of clinical trials. Special attention is paid to practical applications of aromatase inhibitors in the treatment of hormone-dependent mammary and ovarian tumours as well as benign prostatic tumours. In writing this report, the author has used all the information currently available in the chemical, biochemical, endocrinological and medicinal literature as well as in patents. The bibliography includes 173 references.

  11. Aromatase Inhibitors and Other Compounds for Lowering Breast Cancer Risk

    MedlinePlus

    ... Cancer Risk and Prevention Aromatase Inhibitors for Lowering Breast Cancer Risk Aromatase inhibitors (drugs that lower estrogen levels) ... day. Can aromatase inhibitors lower the risk of breast cancer? Aromatase inhibitors are used mainly to treat hormone ...

  12. What determines the inhibition effectiveness of ATA, BTAH, and BTAOH corrosion inhibitors on copper?

    PubMed

    Kokalj, Anton; Peljhan, Sebastijan; Finsgar, Matjaz; Milosev, Ingrid

    2010-11-24

    Three corrosion inhibitors for copper-3-amino-1,2,4-triazole (ATA), benzotriazole (BTAH), and 1-hydroxybenzotriazole (BTAOH)-were investigated by corrosion experiments and atomistic computer simulations. The trend of corrosion inhibition effectiveness of the three inhibitors on copper in near-neutral chloride solution is determined experimentally as BTAH ≳ ATA ≫ BTAOH. A careful analysis of the results of computer simulations based on density functional theory allowed to pinpoint the superior inhibiting action of BTAH and ATA as a result of their ability to form strong N-Cu chemical bonds in deprotonated form. While these bonds are not as strong as the Cl-Cu bonds, the presence of solvent favors the adsorption of inhibitor molecules onto the surface due to stronger solvation of the Cl(-) anions. Moreover, benzotriazole displays the largest affinity among the three inhibitors to form intermolecular aggregates, such as [BTA-Cu](n) polymeric complex. This is another factor contributing to the stability of the protective inhibitor film on the surface, thus making benzotriazole an outstanding corrosion inhibitor for copper. These findings cannot be anticipated on the basis of inhibitors' molecular electronic properties alone, thus emphasizing the importance of a rigorous modeling of the interactions between the components of the corrosion system in corrosion inhibition studies.

  13. Purification and inhibitory profile of phospholipase A2 inhibitors from Australian elapid sera.

    PubMed Central

    Hains, P G; Broady, K W

    2000-01-01

    Although the resistance of snakes to their own venom is well known, until now no investigators have examined the serum of Australian snakes. Here we describe the identification and purification of a range of phospholipase A(2) (PLA(2)) inhibitors from the serum of Australian elapids. All PLA(2) inhibitors were composed of two protein chains, an alpha-chain and a beta-chain. The alpha-chains were approx. 22.5 kDa in size and variably glycosylated, whereas the beta-chains were approx. 19.8 kDa in size and not glycosylated. Identification of isoforms of the two subunit chains was significant because three of the six sera examined were from single snake specimens. In addition, the glycosylation patterns of the alpha-chains were thoroughly investigated in these unpooled sera. The functional and structural properties of the purified inhibitors were studied. Uniquely, a snake PLA(2) inhibitor was found to inhibit human type II PLA(2) enzyme, which has implications for the treatment of the many diseases in which PLA(2) enzymes have been implicated. Further, we demonstrate that the inhibitor forms a non-covalent association with a purified PLA(2) enzyme. Finally, the purified PLA(2) inhibitor was shown to protect in vivo against the lethal affects of a homologous PLA(2) enzyme, suggesting a role for PLA(2) inhibitors in the treatment of snake bite victims. PMID:10657250

  14. Identification of small molecule inhibitors of phosphatidylinositol 3-kinase and autophagy.

    PubMed

    Farkas, Thomas; Daugaard, Mads; Jäättelä, Marja

    2011-11-11

    Macroautophagy (hereafter autophagy) is a lysosomal catabolic pathway that controls cellular homeostasis and survival. It has recently emerged as an attractive target for the treatment of a variety of degenerative diseases and cancer. The targeting of autophagy has, however, been hampered by the lack of specific small molecule inhibitors. Thus, we screened two small molecule kinase inhibitor libraries for inhibitors of rapamycin-induced autophagic flux. The three most potent inhibitors identified conferred profound inhibition of autophagic flux by inhibiting the formation of autophagosomes. Notably, the autophagy inhibitory effects of all three compounds were independent of their established kinase targets, i.e. ataxia telangiectasia mutated for KU55933, protein kinase C for Gö6976, and Janus kinase 3 for Jak3 inhibitor VI. Instead, we identified phosphatidylinositol 3-kinase (PtdIns3K) as a direct target of KU55933 and Gö6976. Importantly, and in contrast to the currently available inhibitors of autophagosome formation (e.g. 3-methyladenine), none of the three compounds inhibited the cell survival promoting class I phosphoinositide 3-kinase-Akt signaling at the concentrations required for effective autophagy inhibition. Accordingly, they proved to be valuable tools for investigations of autophagy-associated cell death and survival. Employing KU55399, we demonstrated that autophagy protects amino acid-starved cells against both apoptosis and necroptosis. Taken together, our data introduce new possibilities for the experimental study of autophagy and can form a basis for the development of clinically relevant autophagy inhibitors.

  15. A human surfactant peptide-elastase inhibitor construct as a treatment for emphysema

    PubMed Central

    Guarnieri, Frank; Spencer, Jean L.; Lucey, Edgar C.; Nugent, Matthew A.; Stone, Phillip J.

    2010-01-01

    Two million Americans suffer from pulmonary emphysema, costing $2.5 billion/year and contributing to 100,000 deaths/year. Emphysema is thought to result from an imbalance between elastase and endogenous inhibitors of elastase, leading to tissue destruction and a loss of alveoli. Decades of research have still not resulted in an effective treatment other than stopping cigarette smoking, a highly addictive behavior. On the basis of our previous work, we hypothesize that small molecule inhibitors of human neutrophil elastase are ineffective because of rapid clearance from the lungs. To develop a long-acting elastase inhibitor with a lung pharmacodynamic profile that has minimal immunogenicity, we covalently linked an elastase inhibitor, similar to a trifluoro inhibitor that was used in clinical trials, to a 25-amino-acid fragment of human surfactant peptide B. We used this construct to prevent human neutrophil elastase-induced emphysema in a rodent model. The elastase inhibitor alone, although in a 70-fold molar excess to elastase in a mixture with <0.6% residual elastase activity, provided no protection from elastase-induced emphysema. Covalently combining an endogenous peptide from the target organ with a synthetic small molecule inhibitor is a unique way of endowing an active compound with the pharmacodynamic profile needed to create in vivo efficacy. PMID:20534582

  16. Platelet P2Y12 Blockers Confer Direct Postconditioning-like Protection in Reperfused Rabbit Hearts

    PubMed Central

    Yang, Xi-Ming; Liu, Yanping; Cui, Lin; Yang, Xiulan; Liu, Yongge; Tandon, Narendra; Kambayashi, Junichi; Downey, James M.; Cohen, Michael V.

    2012-01-01

    Background Blockade of platelet activation during primary percutaneous intervention for acute myocardial infarction is standard care to minimize stent thrombosis. To determine whether antiplatelet agents offer any direct cardioprotective effect, we tested whether they could modify infarction in a rabbit model of ischemia/reperfusion caused by reversible ligation of a coronary artery. Methods and Results The P2Y12 (adenosine diphosphate) receptor blocker cangrelor administered shortly before reperfusion in rabbits undergoing 30-minute regional ischemia/3-hour reperfusion reduced infarction from 38% of ischemic zone in control hearts to only 19%. Protection was dose dependent and correlated with the degree of inhibition of platelet aggregation. Protection was comparable to that seen with ischemic postconditioning (IPOC). Cangrelor protection, but not its inhibition of platelet aggregation, was abolished by the same signaling inhibitors that block protection from IPOC suggesting protection resulted from protective signaling rather than anticoagulation. As with IPOC, protection was lost when cangrelor administration was delayed until 10 minutes after reperfusion and no added protection was seen when cangrelor and IPOC were combined. These findings suggest both IPOC and cangrelor may protect by the same mechanism. No protection was seen when cangrelor was used in crystalloid-perfused isolated hearts indicating some component in whole blood is required for protection. Clopidogrel had a very slow onset of action requiring 2 days of treatment before platelets were inhibited, and only then the hearts were protected. Signaling inhibitors given just prior to reperfusion blocked clopidogrel’s protection. Neither aspirin nor heparin was protective. Conclusions Clopidogrel and cangrelor protected rabbit hearts against infarction. The mechanism appears to involve signal transduction during reperfusion rather than inhibition of intravascular coagulation. We hypothesize that both

  17. Investigating the selectivity of metalloenzyme inhibitors.

    PubMed

    Day, Joshua A; Cohen, Seth M

    2013-10-24

    The inhibitory activity of a broad group of known metalloenzyme inhibitors against a panel of metalloenzymes was evaluated. Clinically approved inhibitors were selected as well as several other reported metalloprotein inhibitors in order to represent a broad range of metal binding groups (MBGs), including hydroxamic acid, carboxylate, hydroxypyridinonate, thiol, and N-hydroxyurea functional groups. A panel of metalloenzymes, including carbonic anhydrase (hCAII), several matrix metalloproteinases (MMPs), angiotensin converting enzyme (ACE), histone deacetylase (HDAC-2), and tyrosinase (TY), was selected based on their clinical importance for a range of pathologies. In addition, each inhibitor was evaluated for its ability to remove Fe(3+) from holo-transferrin to gauge the ability of the inhibitors to access Fe(3+) from a primary transport protein. The results show that the metalloenzyme inhibitors are quite selective for their intended targets, suggesting that despite their ability to bind metal ions, metalloprotein inhibitors are not prone to widespread off-target enzyme inhibition activity.

  18. Inhibitors

    MedlinePlus

    ... Mutation Project (CHAMP) mutation list: a new online resource. Human Mutation. 2012; E2382-E2392. Li T, Miller CH, Payne AB, Hooper CW. The CDC Hemophilia B mutation project mutation list: a new online resource. Molecular Genetics and Genomic Medicine. 2013; 1(4): ...

  19. Anatomy of the pleura.

    PubMed

    Finley, David J; Rusch, Valerie W

    2011-05-01

    The pleura is a monolayer of mesothelial cells covering the lung and inner surface of the chest cavity, creating the pleural space. The mesothelial cells rest on a matrix of collagen, elastic fibers, blood vessels, and lymphatics, which allow the lung and chest to expand and contract, protected from friction by the pleural fluid and properties of the mesothelial cells. With a rich blood supply and lymphatic system just deep to the mesothelial layer, the pleura is a dynamic layer protecting the lung and pleural cavity from infection while transmitting the forces of respiration without damage to the underlying lung parenchyma.

  20. NFκB-regulation of c-FLIP promotes TNFα-mediated RAF inhibitor resistance in melanoma

    PubMed Central

    Shao, Yongping; Le, Kaitlyn; Cheng, Hanyin; Aplin, Andrew E.

    2015-01-01

    Targeted inhibitors elicit heterogeneous clinical responses in genetically stratified groups of patients. While most studies focus on tumor intrinsic properties, factors in the tumor microenvironment were recently found to modulate the response to inhibitors. Here, we show that in cutaneous BRAF V600E melanoma, the cytokine TNFα blocks RAF-inhibitor-induced apoptosis via activation of nuclear factor κB (NFκB). Several NFκB-dependent factors are up-regulated following TNFα and RAF inhibitor treatment. Of these factors, we show that death receptor inhibitor cellular caspase 8 (FLICE)-like inhibitory protein (c-FLIP) is required for TNFα-induced protection against RAF inhibitor. Overexpression of c-FLIP_S or c-FLIP_L isoform decreased RAF inhibitor-induced apoptosis in the absence of TNFα. Importantly, targeting NFκB enhances response to RAF inhibitor in vitro and in vivo. Together, our results show mechanistic evidence for cytokine-mediated resistance to RAF inhibitor and provide a preclinical rationale for the strategy of co-targeting the RAF-MEK-ERK1/2 pathway and the TNFα/NFκB axis to treat mutant BRAF melanomas. PMID:25751672

  1. cap alpha. -Alkenylphenones - A new class of acid corrosion inhibitors

    SciTech Connect

    Frenier, W.W.; Growcock, F.B.; Lopp, V.R. )

    1988-09-01

    In this paper, a new class of corrosion inhibitors for steel in strong HCI is described. When formulated with small amounts of surfactants, ..cap alpha..-Alkenylphenones provide excellent protection for oilfield steel in contact with strong HCI (up to 28%). The protection levels are similar to, and sometimes superior to, those provided by alkynols. In 15% HCI, benzylallyl alcohol (BAA) appears to be a common intermediate, i.e., in the acid after 24 h when any of the four different phenyl ketones are used. Poly(phenylvinyl ketone) (PPVK), which could form on the surface from reaction of absorbed BAA, was the major component of the thin surface film after corrosion tests with the four ketones.

  2. Evaluation of passivation method and corrosion inhibitors for steel-reinforced concrete structures

    NASA Astrophysics Data System (ADS)

    Brown, Richard; Lee, K. Wayne; Cao, Yong

    1999-02-01

    Corrosion of reinforcing steel due to the ingression of chloride ions from deicing salt and/or seawater has been a major cause of the deterioration of reinforced concrete structures. Typically reinforcing steel is protected from corrosion by the formation of passive film because of highly alkaline concrete environment. The film can be damaged with the introduction of chloride ions to concrete, then corrosion occurs. There are mainly three approaches to tackle this problem, i.e., protective coating, cathodic protection and corrosion inhibitors.

  3. Primary CNS lymphoproliferative disease, mycophenolate and calcineurin inhibitor usage

    PubMed Central

    Crane, Genevieve M.; Powell, Helen; Kostadinov, Rumen; Rocafort, Patrick Tim; Rifkin, Dena E.; Burger, Peter C.; Ambinder, Richard F.; Swinnen, Lode J.; Borowitz, Michael J.; Duffield, Amy S.

    2015-01-01

    Immunosuppression for solid organ transplantation increases lymphoproliferative disease risk. While central nervous system (CNS) involvement is more rare, we noticed an increase in primary CNS (PCNS) disease. To investigate a potential association with the immunosuppressive regimen we identified all post-transplant lymphoproliferative disease (PTLD) cases diagnosed over a 28-year period at our institution (174 total, 29 PCNS) and all similar cases recorded in a United Network for Organ Sharing-Organ Procurement and Transplant Network (UNOS-OPTN) data file. While no PCNS cases were diagnosed at our institution between 1986 and 1997, they comprised 37% of PTLD cases diagnosed from 2011–2014. PCNS disease was more often associated with renal vs. other organ transplant, Epstein-Barr virus, large B-cell morphology and mycophenolate mofetil (MMF) as compared to PTLD that did not involve the CNS. Calcineurin inhibitors were protective against PCNS disease when given alone or in combination with MMF. A multivariate analysis of a larger UNOS-OPTN dataset confirmed these findings, where both MMF and lack of calcineurin inhibitor usage were independently associated with risk for development of PCNS PTLD. These findings have significant implications for the transplant community, particularly given the introduction of new regimens lacking calcineurin inhibitors. Further investigation into these associations is warranted. PMID:26460822

  4. MMP Inhibitors on Dentin Stability

    PubMed Central

    Montagner, A.F.; Sarkis-Onofre, R.; Pereira-Cenci, T.; Cenci, M.S.

    2014-01-01

    The aim of this study was to systematically review the literature for in vitro and ex vivo studies that evaluated the effect of matrix metalloproteinase (MMP) inhibitors during the adhesive procedure on the immediate and long-term resin-dentin bond strength. The search was conducted in 6 databases with no publication year or language limits, following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. From 1,336 potentially eligible studies, 48 were selected for full-text analysis, and 30 were included for review, with 17 considered in the meta-analysis. Two reviewers independently selected the studies, extracted the data, and assessed the risk of bias. Pooled effect estimates were expressed as the weighted mean difference between groups. The most used MMP inhibitor was chlorhexidine (CHX). Immediate bond strength results showed no difference between 2% CHX and control; however, a difference was found between 0.2% CHX and control at baseline. After aging, CHX presented higher bond strength values compared to control groups (p < .05). However, this was not observed for longer periods of aging. High heterogeneity was found in some comparisons, especially for the water storage aging subgroup. Subgroup analyses showed that self-etching and etch-and-rinse adhesives are benefited by the CHX use. From the studies included, only 1 presented low risk of bias, while the others showed medium or high risk of bias. The use of MMP inhibitors did not affect the immediate bond strength overall, while it influenced the aged bond strength. Aging procedures influenced bond strength values of the dentin adhesion stability. PMID:24935066

  5. Histone deacetylase inhibitors (HDACIs): multitargeted anticancer agents

    PubMed Central

    Ververis, Katherine; Hiong, Alison; Karagiannis, Tom C; Licciardi, Paul V

    2013-01-01

    Histone deacetylase (HDAC) inhibitors are an emerging class of therapeutics with potential as anticancer drugs. The rationale for developing HDAC inhibitors (and other chromatin-modifying agents) as anticancer therapies arose from the understanding that in addition to genetic mutations, epigenetic changes such as dysregulation of HDAC enzymes can alter phenotype and gene expression, disturb homeostasis, and contribute to neoplastic growth. The family of HDAC inhibitors is large and diverse. It includes a range of naturally occurring and synthetic compounds that differ in terms of structure, function, and specificity. HDAC inhibitors have multiple cell type-specific effects in vitro and in vivo, such as growth arrest, cell differentiation, and apoptosis in malignant cells. HDAC inhibitors have the potential to be used as monotherapies or in combination with other anticancer therapies. Currently, there are two HDAC inhibitors that have received approval from the US FDA for the treatment of cutaneous T-cell lymphoma: vorinostat (suberoylanilide hydroxamic acid, Zolinza) and depsipeptide (romidepsin, Istodax). More recently, depsipeptide has also gained FDA approval for the treatment of peripheral T-cell lymphoma. Many more clinical trials assessing the effects of various HDAC inhibitors on hematological and solid malignancies are currently being conducted. Despite the proven anticancer effects of particular HDAC inhibitors against certain cancers, many aspects of HDAC enzymes and HDAC inhibitors are still not fully understood. Increasing our understanding of the effects of HDAC inhibitors, their targets and mechanisms of action will be critical for the advancement of these drugs, especially to facilitate the rational design of HDAC inhibitors that are effective as antineoplastic agents. This review will discuss the use of HDAC inhibitors as multitargeted therapies for malignancy. Further, we outline the pharmacology and mechanisms of action of HDAC inhibitors while

  6. The use of carboranes as oxidation inhibitors for carbon-carbon composites

    NASA Technical Reports Server (NTRS)

    Petty, John T.

    1991-01-01

    Carbon-carbon composites have many beneficial properties for use in aerospace applications, including their high specific strength and modulus at elevated temperatures. However, they share with all carbon based substances a strong tendency to burn when heated in air. In order to exploit their good qualities, it is necessary to slow or prevent their oxidation during use. Molecular inhibiters offer protection with the advantage of being able to form a homogeneous solution with the resin. Since boron oxides are known to provide the desired kind of protection, molecular compounds based on boron seem reasonable candidates to test as inhibitors. Performance tests indicated that carboranes are excellent materials for obtaining high uniform loadings of boron inhibitors in glassy carbon materials and thus reducing their rates of oxidation. Further, there is evidence that the use of substituted derivatives could provide more complete and thorough forms of protection.

  7. Monoamine Oxidase Inhibitors: Clinical Review

    PubMed Central

    Remick, Ronald A.; Froese, Colleen

    1990-01-01

    Monoamine oxidase inhibitors (MAOIs) are effective antidepressant agents. They are increasingly and effectively used in a number of other psychiatric and non-psychiatric medical syndromes. Their potential for serious toxicity (i.e., hypertensive reaction) is far less than original reports suggest, and newer reversible substrate-specific MAOIs may offer even less toxicity. The author reviews the pharmacology, mechanism of action, clinical indications, and dosing strategies of MAOIs. The common MAOI side-effects (hypotension, weight gain, sexual dysfunction, insomnia, daytime sedation, myoclonus, and hypertensive episodes) are described and management techniques suggested. Recent clinical developments involving MAOIs are outlined. PMID:21233984

  8. Techniques for Screening Translation Inhibitors

    PubMed Central

    Osterman, Ilya A.; Bogdanov, Alexey A.; Dontsova, Olga A.; Sergiev, Petr V.

    2016-01-01

    The machinery of translation is one of the most common targets of antibiotics. The development and screening of new antibiotics usually proceeds by testing antimicrobial activity followed by laborious studies of the mechanism of action. High-throughput methods for new antibiotic screening based on antimicrobial activity have become routine; however, identification of molecular targets is usually a challenge. Therefore, it is highly beneficial to combine primary screening with the identification of the mechanism of action. In this review, we describe a collection of methods for screening translation inhibitors, with a special emphasis on methods which can be performed in a high-throughput manner. PMID:27348012

  9. Natural products as aromatase inhibitors.

    PubMed

    Balunas, Marcy J; Su, Bin; Brueggemeier, Robert W; Kinghorn, A Douglas

    2008-08-01

    With the clinical success of several synthetic aromatase inhibitors (AIs) in the treatment of postmenopausal estrogen receptor-positive breast cancer, researchers have also been investigating the potential of natural products as AIs. Natural products from terrestrial and marine organisms provide a chemically diverse array of compounds not always available through current synthetic chemistry techniques. Natural products that have been used traditionally for nutritional or medicinal purposes (e.g., botanical dietary supplements) may also afford AIs with reduced side effects. A thorough review of the literature regarding natural product extracts and secondary metabolites of plant, microbial, and marine origin that have been shown to exhibit aromatase inhibitory activity is presented herein.

  10. Metabolic responses in Candida tropicalis to complex inhibitors during xylitol bioconversion.

    PubMed

    Wang, Shizeng; Li, Hao; Fan, Xiaoguang; Zhang, Jingkun; Tang, Pingwah; Yuan, Qipeng

    2015-09-01

    During xylitol fermentation, Candida tropicalis is often inhibited by inhibitors in hemicellulose hydrolysate. The mechanisms involved in the metabolic responses to inhibitor stress and the resistances to inhibitors are still not clear. To understand the inhibition mechanisms and the metabolic responses to inhibitors, a GC/MS-based metabolomics approach was performed on C. tropicalis treated with and without complex inhibitors (CI, including furfural, phenol and acetic acid). Partial least squares discriminant analysis was used to determine the metabolic variability between CI-treated groups and control groups, and 25 metabolites were identified as possible entities responsible for the discrimination caused by inhibitors. We found that xylose uptake rate and xylitol oxidation rate were promoted by CI treatment. Metabolomics analysis showed that the flux from xylulose to pentose phosphate pathway increased, and tricarboxylic acid cycle was disturbed by CI. Moreover, the changes in levels of 1,3-propanediol, trehalose, saturated fatty acids and amino acids showed different mechanisms involved in metabolic responses to inhibitor stress. The increase of 1,3-propanediol was considered to be correlated with regulating redox balance and osmoregulation. The increase of trehalose might play a role in protein stabilization and cellular membranes protection. Saturated fatty acids could cause the decrease of membrane fluidity and make the plasma membrane rigid to maintain the integrity of plasma membrane. The deeper understanding of the inhibition mechanisms and the metabolic responses to inhibitors will provide us with more information on the metabolism regulation during xylitol bioconversion and the construction of industrial strains with inhibitor tolerance for better utilization of bioresource.

  11. MSFC Respiratory Protection Services

    NASA Technical Reports Server (NTRS)

    CoVan, James P.

    1999-01-01

    An overview of the Marshall Space Flight Center Respiratory Protection program is provided in this poster display. Respiratory protection personnel, building, facilities, equipment, customers, maintenance and operational activities, and Dynatech fit testing details are described and illustrated.

  12. Endangered Species Protection Bulletins

    EPA Pesticide Factsheets

    Endangered Species Protection Bulletins set forth geographically specific pesticide use limitations for the protection of threatened and endangered (listed) species and their designated critical habitat. Find out how to get and use Bulletins.

  13. Personal protective equipment

    MedlinePlus

    ... medlineplus.gov/ency/patientinstructions/000447.htm Personal protective equipment To use the sharing features on this page, please enable JavaScript. Personal protective equipment is special equipment you wear to create a ...

  14. Skin protection for hairdressers.

    PubMed

    Skudlik, Christoph; John, Swen Malte

    2007-01-01

    The application of protective creams in the hairdressing trade forms part of a complex concept for the prevention of occupational skin disorders. To date, no comparative controlled intervention studies have been carried out using different skin-protective creams. Previously published skin protection plans concerning barrier creams for the hairdressing trade are fairly general or rudimentary, reflecting our still limited knowledge on the subject. Bioengineering studies have even demonstrated a paradoxical effect of a certain skin-protective foam designed for hairdressers. Regarding other barrier creams, a certain protective effect could however be shown in studies concerning exposure to wetness and detergents. Pre-exposition skin protection seems to be of particular relevance. Thus, in principle, the regular application of adequate skin protection creams can be recommended in the hairdressing trade, although the protective effect should not be overvalued.

  15. Differential Chemical Protection of Mammalian Cells from the Exotoxins of ’Corynebacterium diphtheriae’ and ’Pseudomonas aeruginosa’,

    DTIC Science & Technology

    Many drugs or chemicals had markedly different effects on the cytotoxicity induced by Pseudomonas aeruginosa exotoxin A (PE) or Corynebacterium ... diphtheriae exotoxin (DE). The glycolytic inhibitor NaF protected cells from DE but potentiated the cytotoxicity of PE. Another energy inhibitor, salicylic

  16. Experimental and theoretical studies of xanthan gum and its graft co-polymer as corrosion inhibitor for mild steel in 15% HCl

    NASA Astrophysics Data System (ADS)

    Biswas, Amrita; Pal, Sagar; Udayabhanu, G.

    2015-10-01

    Xanthan gum (XG) and its graft co-polymer have been investigated as corrosion inhibitors for mild steel in 15% HCl. Gravimetric analysis, potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) methods were employed for investigating the effectiveness of these inhibitors. Results indicate that both the inhibitors are of mixed type and follow Langmuir adsorption isotherm. Scanning electron microscopy (SEM) study also confirmed the protection of the metal surface by XG and xanthan gum-graft-poly(acrylamide) (XG-g-PAM). Theoretical calculations using Density Functional Theory (DFT) were used to establish the correlation between the structure and corrosion protection efficiencies.

  17. Corium protection assembly

    DOEpatents

    Gou, Perng-Fei; Townsend, Harold E.; Barbanti, Giancarlo

    1994-01-01

    A corium protection assembly includes a perforated base grid disposed below a pressure vessel containing a nuclear reactor core and spaced vertically above a containment vessel floor to define a sump therebetween. A plurality of layers of protective blocks are disposed on the grid for protecting the containment vessel floor from the corium.

  18. Careers in Environmental Protection.

    ERIC Educational Resources Information Center

    Millard, Reed

    The book presents concerns of our society in protecting our environment and the challenges involved in meaningful careers in environmental protection and management. "Estimates by the Environmental Protection Agency indicate that, compared with their numbers in the mid-'70's, the need for environmental professionals will triple by…

  19. Protect Children, Protect Our Future (2010)

    EPA Pesticide Factsheets

    tips to avoid risks from environmental exposure at home, school, and at play. importance of promoting policies, scientific knowledge, diagnosis and treatment, education, and global efforts in protecting children.

  20. Assessment of 105 Patients with Angiotensin Converting Enzyme-Inhibitor Induced Angioedema

    PubMed Central

    von Buchwald, Christian; Prasad, Sumangali Chandra; Kamaleswaran, Shailajah; Ajgeiy, Kawa Khaled; Authried, Georg; Pallesen, Kristine Appel U.

    2017-01-01

    Objective. To asses a cohort of 105 consecutive patients with angiotensin converting enzyme-inhibitor induced angioedema with regard to demographics, risk factors, family history of angioedema, hospitalization, airway management, outcome, and use of diagnostic codes used for the condition. Study Design. Cohort study. Methods. This was a retrospective cohort study of 105 patients with angiotensin converting enzyme-inhibitor induced angioedema in the period 1995–2014. Results. The cohort consisted of 67 females and 38 males (F : M ratio 1.8), with a mean age of 63 [range 26–86] years. Female gender was associated with a significantly higher risk of angiotensin converting enzyme-inhibitor induced angioedema. 6.7% had a positive family history of angioedema. Diabetes seemed to be a protective factor with regard to angioedema. 95% experienced angioedema of the head and neck. 4.7% needed intubation or tracheostomy. 74 admissions took place during the study period with a total of 143 days spent in the hospital. The diagnosis codes most often used for this condition were “DT783 Quincke's oedema” and “DT78.4 Allergy unspecified”. Complement C1 inhibitor was normal in all tested patients. Conclusion. Female gender predisposes to angiotensin converting enzyme-inhibitor induced angioedema, whereas diabetes seems to be a protective factor. PMID:28286522

  1. Combination with γ-secretase inhibitor prolongs treatment efficacy of BRAF inhibitor in BRAF-mutated melanoma cells.

    PubMed

    Zhu, Guannan; Yi, Xiuli; Haferkamp, Sebastian; Hesbacher, Sonja; Li, Chunying; Goebeler, Matthias; Gao, Tianwen; Houben, Roland; Schrama, David

    2016-06-28

    Oncogenic triggering of the MAPK pathway in melanocytes results in senescence, and senescence escape is considered as one critical step for melanocytic transformation. In melanoma, induction of a senescent-like state by BRAF-inhibitors (BRAFi) in a fraction of treated cells - instead of killing - contributes to the repression of tumor growth, but may also provide a source for relapse. Here, we demonstrate that NOTCH activation in melanocytes is not only growth-promoting but it also protects these cells against oncogene-induced senescence. In turn, treatment of melanoma cells with an inhibitor of the NOTCH-activating enzyme γ-secretase led to induction of a senescent-like status in a fraction of the cells but overall achieved only a moderate inhibition of melanoma cell growth. However, combination of γ-secretase inhibitor (GSI) with BRAFi markedly increased the treatment efficacy particularly in long-term culture. Moreover, even melanoma cells starting to regrow after continuous BRAFi treatment - the major problem of BRAFi therapy in patients - can still be affected by the combination treatment. Thus, combining GSI with BRAFi increases the therapeutic efficacy by, at least partially, prolonging the senescent-like state of treated cells.

  2. C1 inhibitor: quantification and purification.

    PubMed

    Varga, Lilian; Dobó, József

    2014-01-01

    C1 inhibitor is a multipotent serpin capable of inhibiting the classical and the lectin pathways of complement, the fibrinolytic system, and contact/kinin system of coagulation. Deficiency of C1 inhibitor manifest as hereditary angioedema (HAE), an autosomal dominant hereditary disease. Measuring the C1 inhibitor level is of vital importance for the diagnosis of HAE and also for monitoring patients receiving C1 inhibitor for therapy. Determination of the antigenic C1 inhibitor level by the radial immunodiffusion (RID) technique is described in detail in this chapter. The presented purification method of plasma C1 inhibitor is primarily based on its high carbohydrate content and its affinity to the lectin jacalin.

  3. Tubulin inhibitors: a patent survey.

    PubMed

    Nepali, Kunal; Ojha, Ritu; Sharma, Sahil; Bedi, Preet M S; Dhar, Kanaya L

    2014-05-01

    Tubulin is one of the most useful and strategic molecular targets for anticancer drugs. The dynamic process of microtubule assembly and disassembly can be blocked by various agents that bind to distinct sites in the β-tubulin subunit. By interfering with microtubule function in vitro, these agents arrest cells in mitosis, eventually leading to cell death, by both apoptosis and necrosis. So far, three binding domains have been identified a) the colchicine site close to the α/β interface, b) the area where the vinca alkaloids bind, and c) the taxane-binding pocket. This review compiles the patent literature up to 2013 and offers a detailed account of all the advances on Tubulin inhibitors (lead molecules) along with in depth knowledge about the number of novel scaffolds, modified analogs and derivatives of the lead molecules. Colchicine binding site remains the most explored site indicated by the patent survey as majority of the patents revolves around phenstatin and combretastatin based molecules where the key structural feature for tubulin inhibition is an appropriate arrangement of the two aromatic rings at an appropriate distance and optimal dihedral angle maximizing interactions with tubulin. A brief account of promising tubulin inhibitors in stages of clinical development and some strategies for the development of potent molecules overcoming the problem of drug resistance have also been discussed.

  4. Aromatase inhibitors and bone loss.

    PubMed

    Perez, Edith A; Weilbaecher, Katherine

    2006-08-01

    The aromatase inhibitors (AIs) anastrozole (Arimidex), letrozole (Femara), and exemestane (Aromasin) are significantly more effective than the selective estrogen-receptor modulator (SERM) tamoxifen in preventing recurrence in estrogen receptor-positive early breast cancer. Aromatase inhibitors are likely to replace SERMs as first-line adjuvant therapy for many patients. However, AIs are associated with significantly more osteoporotic fractures and greater bone mineral loss. As antiresorptive agents, oral and intravenous bisphosphonates such as alendronate (Fosamax), risedronate (Actonel), ibandronate (Boniva), pamidronate (Aredia), and zoledronic acid (Zometa) have efficacy in preventing postmenopausal osteoporosis, cancer treatment-related bone loss, or skeletal complications of metastatic disease. Clinical practice guidelines recommend baseline and annual follow-up bone density monitoring for all patients initiating AI therapy. Bisphosphonate therapy should be prescribed for patients with osteoporosis (T score < -2.5) and considered on an individual basis for those with osteopenia (T score < -1). Modifiable lifestyle behaviors including adequate calcium and vitamin D intake, weight-bearing exercise, and smoking cessation should be addressed. Adverse events associated with bisphosphonates include gastrointestinal toxicity, renal toxicity, and osteonecrosis of the jaw. These safety concerns should be balanced with the potential of bisphosphonates to minimize or prevent the debilitating effects of AI-associated bone loss in patients with early, hormone receptor-positive breast cancer.

  5. Plant Biofilm Inhibitors to Discover Biofilm Genes

    DTIC Science & Technology

    2011-04-08

    REPORT Final Report for Plant Biofilm Inhibitors to Discover Biofilm Genes 14. ABSTRACT 16. SECURITY CLASSIFICATION OF: To control biofilms , we have...synthesized the natural biofilm inhibitor (5Z)-4-bromo-5-(bromomethylene) -3-butyl-2(5H)-furanone from the red alga Delisea pulchra and determined that...Research Office P.O. Box 12211 Research Triangle Park, NC 27709-2211 15. SUBJECT TERMS biofilms , biofilm inhibitors Thomas K. Wood Texas Engineering

  6. The role of complement inhibitors beyond controlling inflammation.

    PubMed

    Blom, A M

    2017-03-26

    The complement system is an arm of innate immunity that aids in the removal of pathogens and dying cells. Due to its harmful, pro-inflammatory potential, complement is controlled by several soluble and membrane-bound inhibitors. This family of complement regulators has been recently extended by the discovery of several new members, and it is becoming apparent that these proteins harbour additional functions. In this review, the current state of knowledge of the physiological functions of four complement regulators will be described: cartilage oligomeric matrix protein (COMP), CUB and sushi multiple domains 1 (CSMD1), sushi domain-containing protein 4 (SUSD4) and CD59. Complement activation is involved in both the development of and defence against cancer. COMP expression is pro-oncogenic, whereas CSMD1 and SUSD4 act as tumour suppressors. These effects may be related in part to the complex influence of complement on cancer but also depend on unrelated functions such as the protection of cells from endoplasmic reticulum stress conveyed by intracellular COMP. CD59 is the main inhibitor of the membrane attack complex, and its deficiency leads to complement attack on erythrocytes and severe haemolytic anaemia, which is now amenable to treatment with an inhibitor of C5 cleavage. Unexpectedly, the intracellular pool of CD59 is crucial for insulin secretion from pancreatic β-cells. This finding is one of several relating to the intracellular functions of complement proteins, which until recently were only considered to be present in the extracellular space. Understanding the alternative functions of complement inhibitors may unravel unexpected links between complement and other physiological systems, but is also important for better design of therapeutic complement inhibition.

  7. Studies of benzamide- and thiol-based histone deacetylase inhibitors in models of oxidative-stress-induced neuronal death: identification of some HDAC3-selective inhibitors.

    PubMed

    Chen, Yufeng; He, Rong; Chen, Yihua; D'Annibale, Melissa A; Langley, Brett; Kozikowski, Alan P

    2009-05-01

    We compare three structurally different classes of histone deacetylase (HDAC) inhibitors that contain benzamide, hydroxamate, or thiol groups as the zinc binding group (ZBG) for their ability to protect cortical neurons in culture from cell death induced by oxidative stress. This study reveals that none of the benzamide-based HDAC inhibitors (HDACIs) provides any neuroprotection whatsoever, in distinct contrast to HDACIs that contain other ZBGs. Some of the sulfur-containing HDACIs, namely the thiols, thioesters, and disulfides present modest neuroprotective activity but show toxicity at higher concentrations. Taken together, these data demonstrate that the HDAC6-selective mercaptoacetamides that were reported previously provide the best protection in the homocysteic acid model of oxidative stress, thus further supporting their study in animal models of neurodegenerative diseases.

  8. Fire Protection Program Manual

    SciTech Connect

    Sharry, J A

    2012-05-18

    This manual documents the Lawrence Livermore National Laboratory (LLNL) Fire Protection Program. Department of Energy (DOE) Orders 420.1B, Facility Safety, requires LLNL to have a comprehensive and effective fire protection program that protects LLNL personnel and property, the public and the environment. The manual provides LLNL and its facilities with general information and guidance for meeting DOE 420.1B requirements. The recommended readers for this manual are: fire protection officers, fire protection engineers, fire fighters, facility managers, directorage assurance managers, facility coordinators, and ES and H team members.

  9. PDE5 inhibitors as therapeutics for heart disease, diabetes and cancer

    PubMed Central

    Das, Anindita; Durrant, David; Salloum, Fadi N; Xi, Lei; Kukreja, Rakesh C

    2015-01-01

    The phosphodiesterase 5 (PDE5) inhibitors, including sildenafil (Viagra™), vardenafil (Levitra™), and tadalafil (Cialis™) have been developed for treatment of erectile dysfunction. Moreover, sildenafil and tadalafil are used for the management of pulmonary arterial hypertension in patients. Since our first report showing the cardioprotective effect of sildenafil in 2002, there has been tremendous growth of preclinical and clinical studies on the use of PDE5 inhibitors for cardiovascular diseases and cancer. Numerous animal studies have demonstrated that PDE5 inhibitors have powerful protective effect against myocardial ischemia/reperfusion (I/R) injury, doxorubicin cardiotoxicity, ischemic and diabetic cardiomyopathy, cardiac hypertrophy, Duchenne muscular dystrophy and the improvement stem cell efficacy for myocardial repair. Mechanistically, PDE5 inhibitors protect the heart against I/R injury through increased expression of nitric oxide synthases, activation of protein kinase G (PKG), PKG-dependent hydrogen sulfide generation, and phosphorylation of glycogen synthase kinase-3β - a master switch immediately proximal to mitochondrial permeability transition pore and the end effector of cardioprotection. In addition, PDE5 inhibitors enhance the sensitivity of certain types of cancer to standard chemotherapeutic drugs, including doxorubicin. Many clinical trials with PDE5 inhibitors have focused on the potential cardiovascular and cancer benefits. Despite mixed results of these clinical trials, there is continuing strong interest by basic scientists and clinical investigators in exploring their new clinical uses. It is our hope that future new mechanistic investigations and carefully designed clinical trials would help in reaping additional benefits of PDE5 inhibitors for cardiovascular disease and cancer in patients. PMID:25444755

  10. Cloning and Characterization of Two Potent Kunitz Type Protease Inhibitors from Echinococcus granulosus

    PubMed Central

    Ranasinghe, Shiwanthi L.; Fischer, Katja; Zhang, Wenbao; Gobert, Geoffrey N.; McManus, Donald P.

    2015-01-01

    The tapeworm Echinococcus granulosus is responsible for cystic echinococcosis (CE), a cosmopolitan disease which imposes a significant burden on the health and economy of affected communities. Little is known about the molecular mechanisms whereby E. granulosus is able to survive in the hostile mammalian host environment, avoiding attack by host enzymes and evading immune responses, but protease inhibitors released by the parasite are likely implicated. We identified two nucleotide sequences corresponding to secreted single domain Kunitz type protease inhibitors (EgKIs) in the E. granulosus genome, and their cDNAs were cloned, bacterially expressed and purified. EgKI-1 is highly expressed in the oncosphere (egg) stage and is a potent chymotrypsin and neutrophil elastase inhibitor that binds calcium and reduced neutrophil infiltration in a local inflammation model. EgKI-2 is highly expressed in adult worms and is a potent inhibitor of trypsin. As powerful inhibitors of mammalian intestinal proteases, the EgKIs may play a pivotal protective role in preventing proteolytic enzyme attack thereby ensuring survival of E. granulosus within its mammalian hosts. EgKI-1 may also be involved in the oncosphere in host immune evasion by inhibiting neutrophil elastase and cathepsin G once this stage is exposed to the mammalian blood system. In light of their key roles in protecting E. granulosus from host enzymatic attack, the EgKI proteins represent potential intervention targets to control CE. This is important as new public health measures against CE are required, given the inefficiencies of available drugs and the current difficulties in its treatment and control. In addition, being a small sized highly potent serine protease inhibitor, and an inhibitor of neutrophil chemotaxis, EgKI-1 may have clinical potential as a novel anti-inflammatory therapeutic. PMID:26645974

  11. [Development of new antiatherosclerotic agents--ACAT inhibitors and CETP inhibitors].

    PubMed

    Miyazaki, A; Horiuchi, S

    1999-12-01

    Development of new antiatherosclerotic agents were reviewed focusing on ACAT inhibitors and CETP inhibitors. ACAT inhibitors enhance intracellular degradation of VLDL in hepatocytes. Cholesterol absorption in small intestine is inhibited by ACAT inhibitors. Thus, ACAT inhibitors reduce plasma cholesterol levels. In atherosclerotic lesions, ACAT inhibitors suppress foam cell formation (cholesteryl ester accumulation) in macrophages. Since ACAT inhibitors have multiple anti-atherogenic effects, they are considered future drugs controlling hypercholesterolemia and atherosclerosis. CETP inhibitors are expected to increase HDL and decrease LDL. Although the patients with CETP deficiency show high level of HDL, recent studies showed that they are not necessarily resistant to atherosclerosis. The strategy to inhibit CETP for suppressing atherosclerosis has not been established.

  12. An Integrated Model of RAF Inhibitor Action Predicts Inhibitor Activity against Oncogenic BRAF Signaling.

    PubMed

    Karoulia, Zoi; Wu, Yang; Ahmed, Tamer A; Xin, Qisheng; Bollard, Julien; Krepler, Clemens; Wu, Xuewei; Zhang, Chao; Bollag, Gideon; Herlyn, Meenhard; Fagin, James A; Lujambio, Amaia; Gavathiotis, Evripidis; Poulikakos, Poulikos I

    2016-09-12

    The complex biochemical effects of RAF inhibitors account for both the effectiveness and mechanisms of resistance to these drugs, but a unified mechanistic model has been lacking. Here we show that RAF inhibitors exert their effects via two distinct allosteric mechanisms. Drug resistance due to dimerization is determined by the position of the αC helix stabilized by inhibitor, whereas inhibitor-induced RAF priming and dimerization are the result of inhibitor-induced formation of the RAF/RAS-GTP complex. The biochemical effect of RAF inhibitor in cells is the combined outcome of the two mechanisms. Therapeutic strategies including αC-helix-IN inhibitors are more effective in multiple mutant BRAF-driven tumor models, including colorectal and thyroid BRAF(V600E) cancers, in which first-generation RAF inhibitors have been ineffective.

  13. Functional differences in epigenetic modulators-superiority of mercaptoacetamide-based histone deacetylase inhibitors relative to hydroxamates in cortical neuron neuroprotection studies.

    PubMed

    Kozikowski, Alan P; Chen, Yufeng; Gaysin, Arsen; Chen, Bin; D'Annibale, Melissa A; Suto, Carla M; Langley, Brett C

    2007-06-28

    We compare the ability of two structurally different classes of epigenetic modulators, namely, histone deacetylase (HDAC) inhibitors containing either a hydroxamate or a mercaptoacetamide as the zinc binding group, to protect cortical neurons in culture from oxidative stress-induced death. This study reveals that some of the mercaptoacetamide-based HDAC inhibitors are fully protective, whereas the hydroxamates show toxicity at higher concentrations. Our present results appear to be consistent with the possibility that the mercaptoacetamide-based HDAC inhibitors interact with a different subset of the HDAC isozymes [less activity at HDAC1 and 2 correlates with less inhibitor toxicity], or alternatively, are interacting selectively with only the cytoplasmic HDACs that are crucial for protection from oxidative stress.

  14. Tyrosine kinase inhibitors enhance ciprofloxacin-induced phototoxicity by inhibiting ABCG2.

    PubMed

    Mealey, Katrina L; Dassanayake, Sandamali; Burke, Neal S

    2014-01-01

    The tyrosine kinase inhibitor (TKI) class of anticancer agents inhibits ABCG2-mediated drug efflux. ABCG2 is an important component of the blood-retinal barrier, where it limits retinal exposure to phototoxic compounds such as fluoroquinolone antibiotics. Patients treated with TKIs would be expected to be at greater risk for retinal phototoxicity. Using an in vitro system, our results indicate that the TKIs gefitinib and imatinib abrogate the ability of ABCG2 to protect cells against ciprofloxacin-induced phototoxicity. We conclude that the concurrent administration of ABCG2 inhibitors with photoreactive fluoroquinolone antibiotics may result in retinal damage.

  15. The sirtuin 2 inhibitor AK-7 is neuroprotective in Huntington's disease mouse models.

    PubMed

    Chopra, Vanita; Quinti, Luisa; Kim, Jinho; Vollor, Lorraine; Narayanan, K Lakshmi; Edgerly, Christina; Cipicchio, Patricia M; Lauver, Molly A; Choi, Soo Hyuk; Silverman, Richard B; Ferrante, Robert J; Hersch, Steven; Kazantsev, Aleksey G

    2012-12-27

    Inhibition of sirtuin 2 (SIRT2) deacetylase mediates protective effects in cell and invertebrate models of Parkinson's disease and Huntington's disease (HD). Here we report the in vivo efficacy of a brain-permeable SIRT2 inhibitor in two genetic mouse models of HD. Compound treatment resulted in improved motor function, extended survival, and reduced brain atrophy and is associated with marked reduction of aggregated mutant huntingtin, a hallmark of HD pathology. Our results provide preclinical validation of SIRT2 inhibition as a potential therapeutic target for HD and support the further development of SIRT2 inhibitors for testing in humans.

  16. The effects of metals and inhibitors on thermal oxidative degradation reactions of unbranched perfluoroalkyl ethers

    NASA Technical Reports Server (NTRS)

    Jones, W. R., Jr.; Paciorek, K. J. L.; Harris, D. H.; Smythe, M. E.; Nakahara, J. H.; Kratzer, R. H.

    1985-01-01

    Thermal oxidative degradation studies were performed on unbranched perfluoroalkylethers at 288 C in oxygen. Metals and alloys studied included Ti, Al, and Ti (4 Al, 4 Mn). The mechanism of degradation was by chain scission. Ti and Al promoted less degradation than Ti (4 Al, 4 Mn). The two inhibitors investigated (a perfluorophenyl phosphine and a phosphatriazine) reduced degradation rates by several orders of magnitude. Both inhibitors were effective for the same duration (75 to 100 hours). The phosphatriazine appeared to provide more surface protection.

  17. The effects of metals and inhibitors on thermal oxidative degradation reactions of unbranched perfluoroalkylethers

    NASA Technical Reports Server (NTRS)

    Jones, W. R., Jr.; Paciorek, K. J. L.; Harris, D. H. L.; Smythe, M. E.; Kratzer, R. H.

    1983-01-01

    Thermal oxidative degradation studies were performed on unbranched perfluoroalkylethers at 288 C in oxygen. Metals and alloys studied included Ti, Al, and Ti (4 Al, 4 Mn). The mechanism of degradation was by chain scission. Ti and Al promoted less degradation than Ti (4 Al, 4 Mn). The two inhibitors investigated (a perfluorophenyl phosphine and a phosphatriazine) reduced degradation rates by several orders of magnitude. Both inhibitors were effective for the same duration (75 to 100 hours). The phosphatriazine appeared to provide more surface protection.

  18. Modulation of the epithelial sodium channel (ENaC) by bacterial metalloproteases and protease inhibitors.

    PubMed

    Butterworth, Michael B; Zhang, Liang; Liu, Xiaoning; Shanks, Robert M; Thibodeau, Patrick H

    2014-01-01

    The serralysin family of metalloproteases is associated with the virulence of multiple gram-negative human pathogens, including Pseudomonas aeruginosa and Serratia marcescens. The serralysin proteases share highly conserved catalytic domains and show evolutionary similarity to the mammalian matrix metalloproteases. Our previous studies demonstrated that alkaline protease (AP) from Pseudomonas aeruginosa is capable of activating the epithelial sodium channel (ENaC), leading to an increase in sodium absorption in airway epithelia. The serralysin proteases are often co-expressed with endogenous, intracellular or periplasmic inhibitors, which putatively protect the bacterium from unwanted or unregulated protease activities. To evaluate the potential use of these small protein inhibitors in regulating the serralysin induced activation of ENaC, proteases from Pseudomonas aeruginosa and Serratia marcescens were purified for characterization along with a high affinity inhibitor from Pseudomonas. Both proteases showed activity against in vitro substrates and could be blocked by near stoichiometric concentrations of the inhibitor. In addition, both proteases were capable of activating ENaC when added to the apical surfaces of multiple epithelial cells with similar slow activation kinetics. The high-affinity periplasmic inhibitor from Pseudomonas effectively blocked this activation. These data suggest that multiple metalloproteases are capable of activating ENaC. Further, the endogenous, periplasmic bacterial inhibitors may be useful for modulating the downstream effects of the serralysin virulence factors under physiological conditions.

  19. Dipeptidyl peptidase-4 inhibitor ameliorates early renal injury through its anti-inflammatory action in a rat model of type 1 diabetes

    SciTech Connect

    Kodera, Ryo; Shikata, Kenichi; Takatsuka, Tetsuharu; Oda, Kaori; Miyamoto, Satoshi; Kajitani, Nobuo; Hirota, Daisho; Ono, Tetsuichiro; Usui, Hitomi Kataoka; Makino, Hirofumi

    2014-01-17

    Highlights: •DPP-4 inhibitor decreased urinary albumin excretion in a rat of type 1 diabetes. •DPP-4 inhibitor ameliorated histlogical changes of diabetic nephropathy. •DPP-4 inhibitor has reno-protective effects through anti-inflammatory action. •DPP-4 inhibitor is beneficial on diabetic nephropathy besides lowering blood glucose. -- Abstract: Introduction: Dipeptidyl peptidase-4 (DPP-4) inhibitors are incretin-based drugs in patients with type 2 diabetes. In our previous study, we showed that glucagon-like peptide-1 (GLP-1) receptor agonist has reno-protective effects through anti-inflammatory action. The mechanism of action of DPP-4 inhibitor is different from that of GLP-1 receptor agonists. It is not obvious whether DPP-4 inhibitor prevents the exacerbation of diabetic nephropathy through anti-inflammatory effects besides lowering blood glucose or not. The purpose of this study is to clarify the reno-protective effects of DPP-4 inhibitor through anti-inflammatory actions in the early diabetic nephropathy. Materials and methods: Five-week-old male Sprague–Dawley (SD) rats were divided into three groups; non-diabetes, diabetes and diabetes treated with DPP-4 inhibitor (PKF275-055; 3 mg/kg/day). PKF275-055 was administered orally for 8 weeks. Results: PKF275-055 increased the serum active GLP-1 concentration and the production of urinary cyclic AMP. PKF275-055 decreased urinary albumin excretion and ameliorated histological change of diabetic nephropathy. Macrophage infiltration was inhibited, and inflammatory molecules were down-regulated by PKF275-055 in the glomeruli. In addition, nuclear factor-κB (NF-κB) activity was suppressed in the kidney. Conclusions: These results indicate that DPP-4 inhibitor, PKF275-055, have reno-protective effects through anti-inflammatory action in the early stage of diabetic nephropathy. The endogenous biological active GLP-1 might be beneficial on diabetic nephropathy besides lowering blood glucose.

  20. Phosphodiesterase 5 inhibitors prevent 3,4-methylenedioxymethamphetamine-induced 5-HT deficits in the rat.

    PubMed

    Puerta, Elena; Hervias, Isabel; Goñi-Allo, Beatriz; Lasheras, Berta; Jordan, Joaquin; Aguirre, Norberto

    2009-02-01

    Phosphodiesterase 5 (PDE5) inhibitors are often used in combination with club drugs such as 3,4-methylenedioxymethamphetamine (MDMA or ecstasy). We investigated the consequences of such combination in the serotonergic system of the rat. Oral administration of sildenafil citrate (1.5 or 8 mg/kg) increased brain cGMP levels and protected in a dose-dependent manner against 5-hydroxytryptamine depletions caused by MDMA (3 x 5 mg/kg, i.p., every 2 h) in the striatum, frontal cortex and hippocampus without altering the acute hyperthermic response to MDMA. Intrastriatal administration of the protein kinase G (PKG) inhibitor, KT5823 [(9S, 10R, 12R)-2,3,9,10,11,12-Hexahydro-10-methoxy-2,9-dimethyl-1-oxo-9,12-epoxy-1H-diindolo[1,2,3-fg:3',2',1'-kl]pyrrolo[3,4-i][1,6]benzodiazocine-10-carboxylic acid, methyl ester)], suppressed sildenafil-mediated protection. By contrast, the cell permeable cGMP analogue, 8-bromoguanosine cyclic 3',5'-monophosphate, mimicked sildenafil effects further suggesting the involvement of the PKG pathway in mediating sildenafil protection. Because mitochondrial ATP-sensitive K(+) channels are a target for PKG, we next administered the specific mitochondrial ATP-sensitive K(+) channel blocker, 5-hydroxydecanoic acid, 30 min before sildenafil. 5-hydroxydecanoic acid completely reversed the protection afforded by sildenafil, thereby implicating the involvement of mitochondrial ATP-sensitive K(+) channels. Sildenafil also increased Akt phosphorylation, and so the possible involvement of the Akt/endothelial nitric oxide synthase (eNOS)/sGC signalling pathway was analysed. Neither the phosphatidylinositol 3-kinase inhibitor, wortmannin, nor the selective eNOS inhibitor, L-N5-(1-iminoethyl)-L-ornithine dihydrochloride, reversed the protection afforded by sildenafil, suggesting that Akt/eNOS/sGC cascade does not participate in the protective mechanisms. Our data also show that the protective effect of sildenafil can be extended to vardenafil, another PDE5

  1. Quorum sensing inhibitors: an overview.

    PubMed

    Kalia, Vipin Chandra

    2013-01-01

    Excessive and indiscriminate use of antibiotics to treat bacterial infections has lead to the emergence of multiple drug resistant strains. Most infectious diseases are caused by bacteria which proliferate within quorum sensing (QS) mediated biofilms. Efforts to disrupt biofilms have enabled the identification of bioactive molecules produced by prokaryotes and eukaryotes. These molecules act primarily by quenching the QS system. The phenomenon is also termed as quorum quenching (QQ). In addition, synthetic compounds have also been found to be effective in QQ. This review focuses primarily on natural and synthetic quorum sensing inhibitors (QSIs) with the potential for treating bacterial infections. It has been opined that the most versatile prokaryotes to produce QSI are likely to be those, which are generally regarded as safe. Among the eukaryotes, certain legumes and traditional medicinal plants are likely to act as QSIs. Such findings are likely to lead to efficient treatments with much lower doses of drugs especially antibiotics than required at present.

  2. Protein farnesyltransferase inhibitors and progeria.

    PubMed

    Meta, Margarita; Yang, Shao H; Bergo, Martin O; Fong, Loren G; Young, Stephen G

    2006-10-01

    Genetic mutations that lead to an accumulation of farnesyl-prelamin A cause progeroid syndromes, including Hutchinson-Gilford progeria syndrome. It seemed possible that the farnesylated form of prelamin A might be toxic to mammalian cells, accounting for all the disease phenotypes that are characteristic of progeria. This concept led to the hypothesis that protein farnesyltransferase inhibitors (FTIs) might ameliorate the disease phenotypes of progeria in mouse models. Thus far, two different mouse models of progeria have been examined. In both models, FTIs improved progeria-like disease phenotypes. Here, prelamin A post-translational processing is discussed and several mutations underlying human progeroid syndromes are described. In addition, recent data showing that FTIs ameliorate disease phenotypes in a pair of mouse models of progeria are discussed.

  3. Macrocyclic Inhibitors of Hsp90

    PubMed Central

    Johnson, Victoria A.; Singh, Erinprit K.; Nazarova, Lidia A.; Alexander, Leslie D.; McAlpine, Shelli R.

    2011-01-01

    Heat shock proteins (HSP) are a family of highly conserved proteins, whose expression increases in response to stresses that may threaten cell survival. Over the past decade, heat shock protein 90 (Hsp90) has emerged as a potential therapeutic target for cancer as it plays a vital role in normal cell maturation and acts as a molecular chaperone for proper folding, assembly, and stabilization of many oncogenic proteins. To date, a majority of Hsp90 inhibitors that have been discovered are macrocycles. The relatively rigid conformation provided by the macrocyclic scaffold allows for a selective interaction with a biological target such as Hsp90. This review highlights the discovery and development of nine macro-cycles that inhibit the function of Hsp90, detailing their potency and the client proteins affected by Hsp90 inhibition. PMID:20536417

  4. Quinolone-based HDAC inhibitors.

    PubMed

    Balasubramanian, Gopalan; Kilambi, Narasimhan; Rathinasamy, Suresh; Rajendran, Praveen; Narayanan, Shridhar; Rajagopal, Sridharan

    2014-08-01

    HDAC inhibitors emerged as promising drug candidates in combating wide variety of cancers. At present, two of the compounds SAHA and Romidepsin were approved by FDA for cutaneous T-cell lymphoma and many are in various clinical phases. A new quinolone cap structure was explored with hydroxamic acid as zinc-binding group (ZBG). The pan HDAC inhibitory and antiproliferative activities against three human cancer cell lines HCT-116 (colon), NCI-H460 (lung) and U251 (glioblastoma) of the compounds (4a-4w) were evaluated. Introduction of heterocyclic amines in CAP region increased the enzyme inhibitory and antiproliferative activities and few of the compounds tested are metabolically stable in both MLM and HLM.

  5. Checkpoint inhibitors in Hodgkin's lymphoma.

    PubMed

    Jezeršek Novaković, Barbara

    2016-04-01

    Hodgkin's lymphoma is unusual among cancers in that it consists of a small number of malignant Hodgkin/Reed-Sternberg cells in a sea of immune system cells, including T cells. Most of these T cells are reversibly inactivated in different ways and their reactivation may induce a very strong immune response to cancer cells. One way of reactivation of T cells is with antibodies blocking the CTLA-4 and especially with antibodies directed against PD-1 or the PD-L1 ligand thereby reversing the tumor-induced downregulation of T-cell function and augmenting antitumor immune activity at the priming (CTLA-4) or tissue effector (PD-1) phase. Immune checkpoint inhibitors have been evidenced as an additional treatment option with substantial effectiveness and acceptable toxicity in heavily pretreated patients with Hodgkin's lymphoma. Particularly, PD-1 blockade with nivolumab and pembrolizumab has demonstrated significant single-agent activity in this select population.

  6. Glycine Transporters and Their Inhibitors

    NASA Astrophysics Data System (ADS)

    Gilfillan, Robert; Kerr, Jennifer; Walker, Glenn; Wishart, Grant

    Glycine plays a ubiquitous role in many biological processes. In the central nervous system it serves as an important neurotransmitter acting as an agonist at strychnine-sensitive glycine receptors and as an essential co-agonist with glutamate at the NMDA receptor complex. Control of glycine concentrations in the vicinity of these receptors is mediated by the specific glycine transporters, GlyT1 and GlyT2. Inhibition of these transporters has been postulated to be of potential benefit in several therapeutic indications including schizophrenia and pain. In this review we discuss our current knowledge of glycine transporters and focus on recent advances in the medicinal chemistry of GlyT1 and GlyT2 inhibitors.

  7. Natural Products as Aromatase Inhibitors

    PubMed Central

    Balunas, Marcy J.; Su, Bin; Brueggemeier, Robert W.; Kinghorn, A. Douglas

    2010-01-01

    With the clinical success of several synthetic aromatase inhibitors (AIs) in the treatment of postmenopausal estrogen receptor-positive breast cancer, researchers have also been investigating also the potential of natural products as AIs. Natural products from terrestrial and marine organisms provide a chemically diverse array of compounds not always available through current synthetic chemistry techniques. Natural products that have been used traditionally for nutritional or medicinal purposes (e.g., botanical dietary supplements) may also afford AIs with reduced side effects. A thorough review of the literature regarding natural product extracts and secondary metabolites of plant, microbial, and marine origin that have been shown to exhibit aromatase inhibitory activity is presented herein. PMID:18690828

  8. Loratadine analogues as MAGL inhibitors.

    PubMed

    Patel, Jayendra Z; Ahenkorah, Stephen; Vaara, Miia; Staszewski, Marek; Adams, Yahaya; Laitinen, Tuomo; Navia-Paldanius, Dina; Parkkari, Teija; Savinainen, Juha R; Walczyński, Krzysztof; Laitinen, Jarmo T; Nevalainen, Tapio J

    2015-04-01

    Compound 12a (JZP-361) acted as a potent and reversible inhibitor of human recombinant MAGL (hMAGL, IC50=46 nM), and was found to have almost 150-fold higher selectivity over human recombinant fatty acid amide hydrolase (hFAAH, IC50=7.24 μM) and 35-fold higher selectivity over human α/β-hydrolase-6 (hABHD6, IC50=1.79 μM). Additionally, compound 12a retained H1 antagonistic affinity (pA2=6.81) but did not show cannabinoid receptor activity, when tested at concentrations ⩽ 10 μM. Hence, compound 12a represents a novel dual-acting pharmacological tool possessing both MAGL-inhibitory and antihistaminergic activities.

  9. Resilience from coastal protection.

    PubMed

    Ewing, Lesley C

    2015-10-28

    Coastal areas are important residential, commercial and industrial areas; but coastal hazards can pose significant threats to these areas. Shoreline/coastal protection elements, both built structures such as breakwaters, seawalls and revetments, as well as natural features such as beaches, reefs and wetlands, are regular features of a coastal community and are important for community safety and development. These protection structures provide a range of resilience to coastal communities. During and after disasters, they help to minimize damages and support recovery; during non-disaster times, the values from shoreline elements shift from the narrow focus on protection. Most coastal communities have limited land and resources and few can dedicate scarce resources solely for protection. Values from shore protection can and should expand to include environmental, economic and social/cultural values. This paper discusses the key aspects of shoreline protection that influence effective community resilience and protection from disasters. This paper also presents ways that the economic, environmental and social/cultural values of shore protection can be evaluated and quantified. It presents the Coastal Community Hazard Protection Resilience (CCHPR) Index for evaluating the resilience capacity to coastal communities from various protection schemes and demonstrates the use of this Index for an urban beach in San Francisco, CA, USA.

  10. Trypsin inhibitors for the treatment of pancreatitis.

    PubMed

    Brandl, Trixi; Simic, Oliver; Skaanderup, Philip R; Namoto, Kenji; Berst, Frederic; Ehrhardt, Claus; Schiering, Nikolaus; Mueller, Irene; Woelcke, Julian

    2016-09-01

    Proline-based trypsin inhibitors occupying the S1-S2-S1' region were identified by an HTS screening campaign. It was discovered that truncation of the P1' moiety and appropriate extension into the S4 region led to highly potent trypsin inhibitors with excellent selectivity against related serine proteases and a favorable hERG profile.

  11. Intellectual property issues of immune checkpoint inhibitors

    PubMed Central

    Storz, Ulrich

    2016-01-01

    Immune checkpoint inhibitors are drugs that interfere with tumor escape responses. Some members of this class are already approved, and expected to be blockbusters in the future. Many companies have developed patent activities in this field. This article focuses on the patent landscape, and discusses key players and cases related to immune checkpoint inhibitors. PMID:26466763

  12. Discovery of novel heterocyclic factor VIIa inhibitors.

    PubMed

    Rai, Roopa; Kolesnikov, Aleksandr; Sprengeler, Paul A; Torkelson, Steven; Ton, Tony; Katz, Bradley A; Yu, Christine; Hendrix, John; Shrader, William D; Stephens, Robin; Cabuslay, Ronnell; Sanford, Ellen; Young, Wendy B

    2006-04-15

    Structure-activity relationships and binding mode of novel heterocyclic factor VIIa inhibitors will be described. In these inhibitors, a highly basic 5-amidinoindole moiety has been successfully replaced with a less basic 5-aminopyrrolo[3,2-b]pyridine scaffold.

  13. Rust inhibitor and oil composition containing same

    SciTech Connect

    Bialy, J.J.; Cullen, W.P.; Dorn, P.; Nebzydoski, J.W.; Sung, R.L.

    1981-04-21

    A rust inhibitor comprising the reaction product of a hydrocarbylsuccinic anhydride in which the hydrocarbyl radical has from about 6 to 30 carbon atoms and an aminotriazole is provided. The rust inhibitor is effective in motor fuel and lubricating oil compositions.

  14. Multiwall thermal protection system

    NASA Technical Reports Server (NTRS)

    Jackson, L. R. (Inventor)

    1982-01-01

    Multiwall insulating sandwich panels are provided for thermal protection of hypervelocity vehicles and other enclosures. In one embodiment, the multiwall panels are formed of alternate layers of dimpled and flat metal (titanium alloy) foil sheets and beaded scarfed edge seals to provide enclosure thermal protection up to 1000 F. An additional embodiment employs an intermediate fibrous insulation for the sandwich panel to provide thermal protection up to 2000 F. A third embodiment employs a silicide coated columbium waffle as the outer panel skin and fibrous layered intermediate protection for thermal environment protection up to 2500 F. The use of multiple panels on an enclosure facilitate repair and refurbishment of the thermal protection system due to the simple support provided by the tab and clip attachment for the panels.

  15. Exploring the scaffold universe of kinase inhibitors.

    PubMed

    Hu, Ye; Bajorath, Jürgen

    2015-01-08

    The scaffold concept was applied to systematically determine, analyze, and compare core structures of kinase inhibitors. From publicly available inhibitors of the human kinome, scaffolds and cyclic skeletons were systematically extracted and organized taking activity data, structural relationships, and retrosynthetic criteria into account. Scaffold coverage varied greatly across the kinome, and many scaffolds representing compounds with different activity profiles were identified. The majority of kinase inhibitor scaffolds were involved in well-defined yet distinct structural relationships, which had different consequences on compound activity. Scaffolds exclusively representing highly potent compounds were identified as well as structurally analogous scaffolds with very different degrees of promiscuity. Scaffold relationships presented herein suggest a variety of hypotheses for inhibitor design. Our detailed organization of the kinase inhibitor scaffold universe with respect to different activity and structural criteria, all scaffolds, and the original compound data assembled for our analysis are made freely available.

  16. Emergency Protection from Aerosols

    SciTech Connect

    Cristy, G.A.

    2001-11-13

    Expedient methods were developed that could be used by an average person, using only materials readily available, to protect himself and his family from injury by toxic (e.g., radioactive) aerosols. The most effective means of protection was the use of a household vacuum cleaner to maintain a small positive pressure on a closed house during passage of the aerosol cloud. Protection factors of 800 and above were achieved.

  17. Protected area management

    USGS Publications Warehouse

    Fagre, Daniel B.; Prato, Tony; Wang, Yeqiao

    2014-01-01

    Designated protected areas are diverse in scope and purpose and have expanded from Yellowstone National Park in the United States, the world’s first national park, to 157,897 parks and protected areas distributed globally. Most are publicly owned and serve multiple needs that reflect regional or national cultures. With ever-increasing threats to the integrity of protected areas, managers are turning to flexible management practices such as scenario planning and adaptive management.

  18. Direct effects protection

    NASA Technical Reports Server (NTRS)

    1977-01-01

    Protection of an aircraft and each of its various systems against the direct effects of lightning were analyzed. Components located in different sections of the aircraft were individually examined since they are likely to experience different degrees of susceptibility to lightning, and may be vulnerable to different components of the lightning flash. The basic steps to be followed in establishing lightning protection were presented by discussing the varieties of arc entry and current flow-through damage. The lightning-strike zones and lightning current environments are established, since environmental conditions in the zones are those under which specific protective measures must perform. Airworthiness regulations which apply to lightning protection are cited.

  19. Protection - Principles and practice.

    NASA Technical Reports Server (NTRS)

    Graham, G. S.; Denning, P. J.

    1972-01-01

    The protection mechanisms of computer systems control the access to objects, especially information objects. The principles of protection system design are formalized as a model (theory) of protection. Each process has a unique identification number which is attached by the system to each access attempted by the process. Details of system implementation are discussed, taking into account the storing of the access matrix, aspects of efficiency, and the selection of subjects and objects. Two systems which have protection features incorporating all the elements of the model are described.

  20. NASA Fire Protection

    NASA Technical Reports Server (NTRS)

    Clark, Theodore

    2001-01-01

    This viewgraph presentation provides information on fire protection operations and administration at Stennis Space Center (SSC). The presentation also lists innovative practices and recent improvements.

  1. Protecting the Amazon with protected areas

    PubMed Central

    Walker, Robert; Moore, Nathan J.; Arima, Eugenio; Perz, Stephen; Simmons, Cynthia; Caldas, Marcellus; Vergara, Dante; Bohrer, Claudio

    2009-01-01

    This article addresses climate-tipping points in the Amazon Basin resulting from deforestation. It applies a regional climate model to assess whether the system of protected areas in Brazil is able to avoid such tipping points, with massive conversion to semiarid vegetation, particularly along the south and southeastern margins of the basin. The regional climate model produces spatially distributed annual rainfall under a variety of external forcing conditions, assuming that all land outside protected areas is deforested. It translates these results into dry season impacts on resident ecosystems and shows that Amazonian dry ecosystems in the southern and southeastern basin do not desiccate appreciably and that extensive areas experience an increase in precipitation. Nor do the moist forests dry out to an excessive amount. Evidently, Brazilian environmental policy has created a sustainable core of protected areas in the Amazon that buffers against potential climate-tipping points and protects the drier ecosystems of the basin. Thus, all efforts should be made to manage them effectively. PMID:19549819

  2. Protecting the Amazon with protected areas.

    PubMed

    Walker, Robert; Moore, Nathan J; Arima, Eugenio; Perz, Stephen; Simmons, Cynthia; Caldas, Marcellus; Vergara, Dante; Bohrer, Claudio

    2009-06-30

    This article addresses climate-tipping points in the Amazon Basin resulting from deforestation. It applies a regional climate model to assess whether the system of protected areas in Brazil is able to avoid such tipping points, with massive conversion to semiarid vegetation, particularly along the south and southeastern margins of the basin. The regional climate model produces spatially distributed annual rainfall under a variety of external forcing conditions, assuming that all land outside protected areas is deforested. It translates these results into dry season impacts on resident ecosystems and shows that Amazonian dry ecosystems in the southern and southeastern basin do not desiccate appreciably and that extensive areas experience an increase in precipitation. Nor do the moist forests dry out to an excessive amount. Evidently, Brazilian environmental policy has created a sustainable core of protected areas in the Amazon that buffers against potential climate-tipping points and protects the drier ecosystems of the basin. Thus, all efforts should be made to manage them effectively.

  3. A Spider-Derived Kunitz-Type Serine Protease Inhibitor That Acts as a Plasmin Inhibitor and an Elastase Inhibitor

    PubMed Central

    Wan, Hu; Lee, Kwang Sik; Kim, Bo Yeon; Zou, Feng Ming; Yoon, Hyung Joo; Je, Yeon Ho; Li, Jianhong; Jin, Byung Rae

    2013-01-01

    Kunitz-type serine protease inhibitors are involved in various physiological processes, such as ion channel blocking, blood coagulation, fibrinolysis, and inflammation. While spider-derived Kunitz-type proteins show activity in trypsin or chymotrypsin inhibition and K+ channel blocking, no additional role for these proteins has been elucidated. In this study, we identified the first spider (Araneus ventricosus) Kunitz-type serine protease inhibitor (AvKTI) that acts as a plasmin inhibitor and an elastase inhibitor. AvKTI possesses a Kunitz domain consisting of a 57-amino-acid mature peptide that displays features consistent with Kunitz-type inhibitors, including six conserved cysteine residues and a P1 lysine residue. Recombinant AvKTI, expressed in baculovirus-infected insect cells, showed a dual inhibitory activity against trypsin (Ki 7.34 nM) and chymotrypsin (Ki 37.75 nM), defining a role for AvKTI as a spider-derived Kunitz-type serine protease inhibitor. Additionally, AvKTI showed no detectable inhibitory effects on factor Xa, thrombin, or tissue plasminogen activator; however, AvKTI inhibited plasmin (Ki 4.89 nM) and neutrophil elastase (Ki 169.07 nM), indicating that it acts as an antifibrinolytic factor and an antielastolytic factor. These findings constitute molecular evidence that AvKTI acts as a plasmin inhibitor and an elastase inhibitor and also provide a novel view of the functions of a spider-derived Kunitz-type serine protease inhibitor. PMID:23308198

  4. [Effect of corrosion inhibitor on the producing of exopolymer complex by sulphate-reducing bacteria].

    PubMed

    Purish, L M; Asaulenko, L H; Kozlova, I P

    2007-01-01

    It is established that the specific productivity of exopolymer complex (EPM) synthesized by the cells of sulphate-reducing bacteria in a biofilm was 1.5 times higher than in plankton. A sharp increase of the specific productivity of EPM in the biofilm is observed when corrosion inhibitor is introduced in the environment. The inhibitor concentration being 1.0 g/l, the biofilm cells produced almost 18 times more of EPM than the bacteria cells in plankton. It is shown that the film exopolymers include glucose, galactose, mannose, xylose, ribose and three nondetermined sugars, while plankton cells also include rhamnose. Rhamnose appeared in the biofilm EPM composition and rhamnose, arabinose and fucose appeared in EPM of plankton cells as affected by the inhibitor. A necessity of investigating the biofilm formation for developing the methods of anticorrosive protection is discussed.

  5. Rational design and simple chemistry yield a superior, neuroprotective HDAC6 inhibitor, tubastatin A.

    PubMed

    Butler, Kyle V; Kalin, Jay; Brochier, Camille; Vistoli, Guilio; Langley, Brett; Kozikowski, Alan P

    2010-08-11

    Structure-based drug design combined with homology modeling techniques were used to develop potent inhibitors of HDAC6 that display superior selectivity for the HDAC6 isozyme compared to other inhibitors. These inhibitors can be assembled in a few synthetic steps, and thus are readily scaled up for in vivo studies. An optimized compound from this series, designated Tubastatin A, was tested in primary cortical neuron cultures in which it was found to induce elevated levels of acetylated alpha-tubulin, but not histone, consistent with its HDAC6 selectivity. Tubastatin A also conferred dose-dependent protection in primary cortical neuron cultures against glutathione depletion-induced oxidative stress. Importantly, when given alone at all concentrations tested, this hydroxamate-containing HDAC6-selective compound displayed no neuronal toxicity, thus, forecasting the potential application of this agent and its analogues to neurodegenerative conditions.

  6. 5-((3-Amidobenzyl)oxy)nicotinamides as Sirtuin 2 Inhibitors.

    PubMed

    Ai, Teng; Wilson, Daniel J; More, Swati S; Xie, Jiashu; Chen, Liqiang

    2016-04-14

    Derived from our previously reported human sirtuin 2 (SIRT2) inhibitors that were based on a 5-aminonaphthalen-1-yloxy nicotinamide core structure, 5-((3-amidobenzyl)oxy)nicotinamides offered excellent activity against SIRT2 and high isozyme selectivity over SIRT1 and SIRT3. Selected compounds also exhibited generally favorable in vitro absorption, distribution, metabolism, and excretion properties. Kinetic studies revealed that a representative SIRT2 inhibitor acted competitively against both NAD(+) and the peptide substrate, an inhibitory modality that was supported by our computational study. More importantly, two selected compounds exhibited significant protection against α-synuclein aggregation-induced cytotoxicity in SH-SY5Y cells. Therefore, 5-((3-amidobenzyl)oxy)nicotinamides represent a new class of SIRT2 inhibitors that are attractive candidates for further lead optimization in our continued effort to explore selective inhibition of SIRT2 as a potential therapy for Parkinson's disease.

  7. Identification of baicalein as a ferroptosis inhibitor by natural product library screening.

    PubMed

    Xie, Yangchun; Song, Xinxin; Sun, Xiaofang; Huang, Jin; Zhong, Meizuo; Lotze, Michael T; Zeh, Herbert J; Kang, Rui; Tang, Daolin

    2016-05-13

    Ferroptosis, a novel form of regulated cell death, is characterized by oxidative injury from iron accumulation and lipid peroxidation. In a natural product library screening for ferroptosis inhibitor, we found that baicalein is a potent inhibitor of erastin-induced ferroptosis in pancreatic cancer cells. Baicalein (also termed 5,6,7-trihydroxyflavone) is a flavonoid originally obtained from the roots of Scutellaria baicalensis and Scutellaria lateriflora. We showed that baicalein exhibits remarkable anti-ferroptosis activity compared with well-known ferroptosis inhibitors such as ferrostatin-1, liproxstatin-1, deferoxamine mesylate, and β-mercaptoethanol. At the biochemistry level, baicalein limits erastin-induced ferrous iron production, glutathione depletion, and lipid peroxidation. At the protein level, baicalein suppresses erastin-mediated degradation of glutathione peroxidase 4, a phospholipid hydroperoxidase that protects cells against membrane lipid peroxidation. Thus, baicalein enhances cellular anti-ferroptosis capacity and could be a potential therapeutic agent for ferroptosis-associated tissue injury.

  8. Beyond gastric acid reduction: Proton pump inhibitors induce heme oxygenase-1 in gastric and endothelial cells

    SciTech Connect

    Becker, Jan C. . E-mail: beckeja@uni-muenster.de; Grosser, Nina; Waltke, Christian; Schulz, Stephanie; Erdmann, Kati; Domschke, Wolfram; Schroeder, Henning; Pohle, Thorsten

    2006-07-07

    Proton pump inhibitors (PPIs) have been demonstrated to prevent gastric mucosal injury by mechanisms independent of acid inhibition. Here we demonstrate that both omeprazole and lansoprazole protect human gastric epithelial and endothelial cells against oxidative stress. This effect was abrogated in the presence of the heme oxygenase-1 (HO-1) inhibitor ZnBG. Exposure to either PPI resulted in a strong induction of HO-1 expression on mRNA and protein level, and led to an increased activity of this enzyme. Expression of cyclooxygenase isoforms 1 and 2 remained unaffected, and COX-inhibitors did not antagonize HO-1 induction by PPIs. Our results suggest that the antioxidant defense protein HO-1 is a target of PPIs in both endothelial and gastric epithelial cells. HO-1 induction might account for the gastroprotective effects of PPIs independently of acid inhibition, especially in NSAID gastropathy. Moreover, our findings provide additional perspectives for a possible but yet unexplored use of PPIs in vasoprotection.

  9. Designing Inhibitors of Anthrax Toxin

    PubMed Central

    Nestorovich, Ekaterina M.; Bezrukov, Sergey M.

    2014-01-01

    Introduction Present-day rational drug design approaches are based on exploiting unique features of the target biomolecules, small- or macromolecule drug candidates, and physical forces that govern their interactions. The 2013 Nobel Prize in chemistry awarded “for the development of multiscale models for complex chemical systems” once again demonstrated the importance of the tailored drug discovery that reduces the role of the trial and error approach to a minimum. The “rational drug design” term is rather comprehensive as it includes all contemporary methods of drug discovery where serendipity and screening are substituted by the information-guided search for new and existing compounds. Successful implementation of these innovative drug discovery approaches is inevitably preceded by learning the physics, chemistry, and physiology of functioning of biological structures under normal and pathological conditions. Areas covered This article provides an overview of the recent rational drug design approaches to discover inhibitors of anthrax toxin. Some of the examples include small-molecule and peptide-based post-exposure therapeutic agents as well as several polyvalent compounds. The review also directs the reader to the vast literature on the recognized advances and future possibilities in the field. Expert opinion Existing options to combat anthrax toxin lethality are limited. With the only anthrax toxin inhibiting therapy (PA-targeting with a monoclonal antibody, raxibacumab) approved to treat inhalational anthrax, in our view, the situation is still insecure. The FDA’s animal rule for drug approval, which clears compounds without validated efficacy studies on humans, creates a high level of uncertainty, especially when a well-characterized animal model does not exist. Besides, unlike PA, which is known to be unstable, LF remains active in cells and in animal tissues for days. Therefore, the effectiveness of the post-exposure treatment of the individuals

  10. Self-healing coatings based on halloysite clay polymer composites for protection of copper alloys.

    PubMed

    Abdullayev, Elshad; Abbasov, Vagif; Tursunbayeva, Asel; Portnov, Vasiliy; Ibrahimov, Hikmat; Mukhtarova, Gulbaniz; Lvov, Yuri

    2013-05-22

    Halloysite clay nanotubes loaded with corrosion inhibitors benzotriazole (BTA), 2-mercaptobenzimidazole (MBI), and 2-mercaptobenzothiazole (MBT) were used as additives in self-healing composite paint coating of copper. These inhibitors form protective films on the metal surface and mitigate corrosion. Mechanisms involved in the film formation have been studied with optical and electron microscopy, UV-vis spectrometry, and adhesivity tests. Efficiency of the halloysite lumen loading ascended in the order of BTA < MBT < MBI; consequently, MBI and MBT halloysite formulations have shown the best protection. Inhibitors were kept in the tubes buried in polymeric paint layer for a long time and release was enhanced in the coating defects exposed to humid media with 20-50 h, sufficient for formation of protective layer. Anticorrosive performance of the halloysite-based composite acrylic and polyurethane coatings have been demonstrated for 110-copper alloy strips exposed to 0.5 M aqueous NaCl for 6 months.

  11. Plant cell walls: Protecting the barrier from degradation by microbial enzymes.

    PubMed

    Lagaert, Stijn; Beliën, Tim; Volckaert, Guido

    2009-12-01

    Plant cell walls are predominantly composed of polysaccharides, which are connected in a strong, yet resilient network. They determine the size and shape of plant cells and form the interface between the cell and its often hostile environment. To penetrate the cell wall and thus infect plants, most phytopathogens secrete numerous cell wall degrading enzymes. Conversely, as a first line of defense, plant cell walls contain an array of inhibitors of these enzymes. Scientific knowledge on these inhibitors significantly progressed in the past years and this review is meant to give a comprehensive overview of plant inhibitors against microbial cell wall degrading enzymes and their role in plant protection.

  12. Review article: immediate-release proton-pump inhibitor therapy--potential advantages.

    PubMed

    Howden, C W

    2005-12-01

    The absorption of most oral proton-pump inhibitors is delayed by the enteric coating required to protect the acid-labile proton-pump inhibitor from degradation in the stomach and, as a result, antisecretory effect is also delayed. This article provides an overview of the pharmacokinetics and pharmacodynamics of a new immediate-release omeprazole [(IR-OME) Zegerid power for oral suspension; Santarus Inc., San Diego, CA, USA] and its potential advantages over delayed-release proton-pump inhibitors. Immediate-release omeprazole has a higher mean peak plasma omeprazole concentration (C(max)) and a significantly shorter mean time to reach C(max) (t(max)) than delayed-release omeprazole. Immediate-release omeprazole 40 mg has a prolonged antisecretory effect with median intragastric pH above 4.0 for 18.6 h/day at steady-state, after 7 days of once daily dosing. The sodium bicarbonate in immediate-release omeprazole protects the uncoated omeprazole from degradation by gastric acid. The accelerated antisecretory action of immediate-release omeprazole compared with delayed-release omeprazole may be due to the activation of proton pumps by the rapid neutralization of intragastric acid by the sodium bicarbonate. The faster onset of action seen with immediate-release omeprazole is not achieved by using an antacid with a delayed-release proton-pump inhibitor, because administering antacids with conventional delayed-release proton-pump inhibitors does not significantly enhance absorption of the proton-pump inhibitor. In conclusion, immediate-release omeprazole is associated with rapid absorption of omeprazole and rapid onset of antisecretory effect, without compromising the duration of acid suppression.

  13. Nanostructured Protective Coatings

    DTIC Science & Technology

    2006-01-01

    potential superior wear resistance properties. The Nanostructured Protective Coatings (NPC) program was designed to establish a collaborative team of...understanding of PVD parameters, depositing coatings on practical substrates such as the Ti6Al4V used for turbine blades , and developing a versatile...Nanostructured Protective Coatings (NPC) program was designed to establish a collaborative team of three entities (Pennsylvania State University

  14. Protection of the Librarian.

    ERIC Educational Resources Information Center

    Sable, M. H.

    1984-01-01

    Explores three potential sources of harrassment from whom the librarian requires protection--patrons, lower-echelon supervisors, and library administrators. Types of protection provided by library associations, the courts, unionization, librarians' professional goals, actions of progressive administrators, collective bargaining, and public and…

  15. Protection and Safety.

    ERIC Educational Resources Information Center

    American School Board Journal, 1964

    1964-01-01

    Several aspects of school safety and protection are presented for school administrators and architects. Among those topics discussed are--(1) life safety, (2) vandalism controlled through proper design, (3) personal protective devices, and (4) fire alarm systems. Another critical factor in providing a complete school safety program is proper…

  16. Protective Garment Ensemble

    NASA Technical Reports Server (NTRS)

    Wakefield, M. E.

    1982-01-01

    Protective garment ensemble with internally-mounted environmental- control unit contains its own air supply. Alternatively, a remote-environmental control unit or an air line is attached at the umbilical quick disconnect. Unit uses liquid air that is vaporized to provide both breathing air and cooling. Totally enclosed garment protects against toxic substances.

  17. Protective Health Education

    ERIC Educational Resources Information Center

    Aydin, Ganime

    2016-01-01

    Problem Statement: As a result of wars, starvation, traffic accidents, homicide, infectious diseases, insufficient adult protection, migration, and inadequate legal reforms the mortality rate of children has become a serious problem in the world. Protective health education contributes to a child's physical and social health. In this case, the…

  18. Protecting the Crown Jewels.

    ERIC Educational Resources Information Center

    Andrus, Cecil

    1979-01-01

    The National Park Service seeks to set the standard for environmental protection in the federally-owned lands which it administers. Often pollution from sources outside park boundaries creates adverse impacts within the parks. Innovative approaches and cooperative efforts are then required to protect the parks. (RE)

  19. Environmental protection Implementation Plan

    SciTech Connect

    R. C. Holland

    1999-12-01

    This ``Environmental Protection Implementation Plan'' is intended to ensure that the environmental program objectives of Department of Energy Order 5400.1 are achieved at SNL/California. This document states SNL/California's commitment to conduct its operations in an environmentally safe and responsible manner. The ``Environmental Protection Implementation Plan'' helps management and staff comply with applicable environmental responsibilities.

  20. Current use of phosphodiesterase inhibitors in urology

    PubMed Central

    Hakky, Tariq Said; Jain, Lakshay

    2015-01-01

    The causes of male erectile dysfunction (ED) are quite variable and are now commonly divided into etiologies such as ischemia, smooth muscle damage, or altered blood flow. Although varying rates of ED have been reported in literature, the number of men with ED is projected to increase worldwide by 2025 to approximately 322 million. Since the introduction of phosphodiesterase 5 (PDE5) inhibitors, there has been a paradigm shift in the treatment of ED because PDE5 inhibitors address a broad spectrum of etiologies for ED. Today, the American Urological Association recommends the use of three PDE5 inhibitors (sildenafil, tadalafil, and vardenafil) as a first-line therapy for the treatment of ED. This review evaluates the pharmacological mechanism of PDE5 inhibitors along with the impact and use of sildenafil, vardenafil, tadalafil, and avanafil. By increasing intracellular cGMP levels, PDE5 inhibitors have been shown to be effective in the treatment of ED. Through their effects on other cellular signaling pathways, PDE5 inhibitors have the potential for treating other urologic conditions as well. The use of PDE5 inhibitors can also be combined to produce a synergistic effect in conditions such as male hypogonadism and benign prostatic hyperplasia in addition to ED. PMID:26328208

  1. Leflunomide, a Reversible Monoamine Oxidase Inhibitor.

    PubMed

    Petzer, Jacobus P; Petzer, Anél

    2016-01-01

    A screening study aimed at identifying inhibitors of the enzyme, monoamine oxidase (MAO), among clinically used drugs have indicated that the antirheumatic drug, leflunomide, is an inhibitor of both MAO isoforms. Leflunomide inhibits human MAO-A and MAO-B and exhibits IC50 values of 19.1 μM and 13.7 μM, respectively. The corresponding Ki values are 17.7 μM (MAO-A) and 10.1 μM (MAO-B). Dialyses of mixtures of the MAO enzymes and leflunomide show that inhibition of the MAOs by leflunomide is reversible. The principal metabolite of leflunomide, teriflunomide (A77 1726), in contrast is not an MAO inhibitor. This study concludes that, although leflunomide is only moderately potent as an MAO inhibitor, isoxazole derivatives may represent a general class of MAO inhibitors and this heterocycle may find application in MAO inhibitor design. In this respect, MAO inhibitors are used in the clinic for the treatment of depressive illness and Parkinson's disease, and are under investigation as therapy for certain types of cancer, Alzheimer's disease and age-related impairment of cardiac function.

  2. Nonpeptide Macrocyclic Histone Deacetylase Inhibitors

    PubMed Central

    Oyelere, Adegboyega K.; Chen, Po C.; Guerrant, William; Mwakwari, Sandra C.; Hood, Rebecca; Zhang, Yunzhe; Fan, Yuhong

    2009-01-01

    Inhibition of Histone Deacetylases inhibitors (HDACi) hold great promise in cancer therapy due to their demonstrated ability to arrest proliferation of nearly all transformed cell types. Of the several structurally distinct small molecules HDACi reported, macrocyclic depsipeptides have the most complex recognition cap-group moieties and present an excellent opportunity for the modulation of the biological activities of HDACi. Unfortunately, the structure–activity relationship (SAR) studies for this class of compounds have been impaired largely because most macrocyclic HDACi known to date are comprised of complex peptide macrocycles. In addition to retaining the pharmacologically disadvantaged peptidyl-backbone, they offer only limited opportunity for side-chain modifications. Here we report the discovery of a new class of macrocyclic HDACi based on the macrolide antibiotics skeletons. SAR studies revealed that these compounds displayed both linker-length and macrolide-type dependent HDAC inhibition activities with IC50 in low nanomolar range. In addition, these nonpeptide macrocyclic HDACi are more selective against HDAC 1 and 2 relative to HDAC 8, another class I HDAC isoform, hence have sub-class HDAC isoform selectivity. PMID:19093884

  3. Inhibitors of specific ceramide synthases.

    PubMed

    Schiffmann, Susanne; Hartmann, Daniela; Fuchs, Sina; Birod, Kerstin; Ferreiròs, Nerea; Schreiber, Yannick; Zivkovic, Aleksandra; Geisslinger, Gerd; Grösch, Sabine; Stark, Holger

    2012-02-01

    Ceramide synthases (CerSs) are key enzymes in the biosynthesis of ceramides and display a group of at least six different isoenzymes (CerS1-6). Ceramides itself are bioactive molecules. Ceramides with different N-acyl side chains (C(14:0)-Cer - C(26:0)-Cer) possess distinct roles in cell signaling. Therefore, the selective inhibition of specific CerSs which are responsible for the formation of a specific ceramide holds promise for a number of new clinical treatment strategies, e.g., cancer. Here, we identified four of hitherto unknown functional inhibitors of CerSs derived from the FTY720 (Fingolimod) lead structure and showed their inhibitory effectiveness by two in vitro CerS activity assays. Additionally, we tested the substances in two cell lines (HCT-116 and HeLa) with different ceramide patterns. In summary, the in vitro activity assays revealed out that ST1058 and ST1074 preferentially inhibit CerS2 and CerS4, while ST1072 inhibits most potently CerS4 and CerS6. Importantly, ST1060 inhibits predominately CerS2. First structure-activity relationships and the potential biological impact of these compounds are discussed.

  4. COMT inhibitors and liver toxicity.

    PubMed

    Watkins, P

    2000-01-01

    This paper reviews the issue of hepatotoxicity with the use of the catechol-O-methly transferase (COMT) inhibitors tolcapone and entacapone. Neither drug caused hepatotoxicity in preclinical toxicity testing. However, in clinical trials of tolcapone, liver chemistry tests were elevated more than 3 times above the upper limit of normal in approximately 1% of patients who took the 100 mg dose and in approximately 3% of patients who took the 200 mg dose. These observations led to the recommendation that periodic monitoring of liver function be performed. Post-marketing surveillance studies noted 3 instances of acute liver failure with death after 60,000 patients had received tolcapone for a total of 40,000 patient-years. For this reason, the drug was withdrawn from the market in Europe and Canada, and a black box warning issued in the United States. In contrast, clinical trials with entacapone demonstrated no increase in liver enzymes above those observed with placebo. Further, no instances of acute liver failure or death attributed to the drug have been observed in post-marketing surveillance studies. Consequently, liver monitoring is not required with this agent. These data demonstrate that tolcapone is associated with a risk of hepatotoxicity but that no such risk has been detected with entacapone.

  5. Pharmacology of Proton Pump Inhibitors

    PubMed Central

    Shin, Jai Moo; Sachs, George

    2010-01-01

    The gastric H,K-ATPase is the primary target for the treatment of acid-related diseases. Proton pump inhibitors (PPIs) are weak bases composed of two moieties, a substituted pyridine with a primary pKa of about 4.0, which allows selective accumulation in the secretory canaliculus of the parietal cell, and a benzimidazole with a second pKa of about 1.0. PPIs are acid-activated prodrugs that convert to sulfenic acids or sulfenamides that react covalently with one or more cysteines accessible from the luminal surface of the ATPase. Because of covalent binding, their inhibitory effects last much longer than their plasma half-life. However, the short half-life of the drug in the blood and the requirement for acid activation impair their efficacy in acid suppression, particularly at night. PPIs with longer half-life promise to improve acid suppression. All PPIs give excellent healing of peptic ulcers and produce good results in reflux esophagitis. PPIs combined with antibiotics eradicate Helicobacter pylori. PMID:19006606

  6. Protection of multimaterial assemblies

    NASA Astrophysics Data System (ADS)

    Mikhail, L. Zheludkevich; Silvar, Kallip; Maria, Serdechnova

    2016-01-01

    The light-weight design calls for broader utilization of multimaterial mixes (M3) in different engineering structures, especially in the transportation area. Together with joining technologies for hybrid structures, the optimization of the life cycle of such systems is an issue of prime importance. Multimaterial structures are often prone to faster degradation under service conditions because of galvanically forced electrochemical corrosion. The protection technologies traditionally used for single-material structures are not always applicable for multimaterial design because of compatibility issues and a stronger thermodynamic driving force for degradation. In this chapter different strategies for protection of multimaterials structures are briefly overviewed. The main focus is on new alternative protection systems based on combination of synergistic inhibiting mixtures introduced into protective coatings. A road map which can be followed in order to create an efficient active protection coating for hybrid structures is suggested.

  7. Redox-responsive self-healing for corrosion protection.

    PubMed

    Vimalanandan, Ashokanand; Lv, Li-Ping; Tran, The Hai; Landfester, Katharina; Crespy, Daniel; Rohwerder, Michael

    2013-12-23

    Raspberry-shaped redox-responsive capsules for storing corrosion inhibitors are introduced, targeted to solve the drawbacks of conducting-polymer-based coating systems for corrosion protection. These capsules synthesized via the miniemulsion technique have a remarkable release property upon reduction (onset of corrosion) and cease release upon reoxidation (passivation of the defect). The self-healing capability is demonstrated by application of these capsules as part of a composite coating on zinc.

  8. [Formation of microbial populations on the surface of protective coatings].

    PubMed

    Kopteva, Zh P; Zanina, V V; Piliashenko-Novokhatnyĭ, A I; Kopteva, A E; Kozlova, I A

    2001-01-01

    Formation of microbial cenosis on the surface of polyethylene-, polyurethane- and oil-bitumen-based protective coatings was studied in dynamics during 1, 3, 7, 14 and 21 days. It has been shown that the biofilm was formed on the protective materials during 14 days and consisted of ammonifying, denitrifying, hydrocarbon-oxidizing and sulphate-reducing bacteria referred to Pseudomonas, Arthrobacter, Bacillus and Kesulfovibrio genera. The bacteria which form the biofilm on coatings possess high denitrifying and sulphate-reducing activities. Corrosion inhibitors-biocydes, introduced in composition of oil-bitumen coatings suppressed growth and metabolic activity of corrosion-active bacteria.

  9. Analysis of corrosion resistance behavior of inhibitors in concrete using electrochemical techniques

    NASA Astrophysics Data System (ADS)

    Song, Ha-Won; Saraswathy, Velu

    2006-08-01

    Reinforced concrete is one of the most durable and cost effective construction materials. However, in high chloride environments, it can suffer from corrosion due to chloride induced breakdown of the normal passive layer protecting the reinforcing steel bars inside concrete. One means of protecting embedded steel reinforcement from chloride induced corrosion is the addition of corrosion inhibiting admixtures. In the present investigation, various inhibitors such as sodium nitrite, zinc oxide, mono ethanol amine, diethanolamine, and triethanol amine have been used in concrete in different percentages. Their effectiveness was then studied using various electrochemical techniques such as rapid chloride ion penetration test, open circuit potential measurement, electrochemical impedance measurement, potentiodynamic polarization measurement, and gravimetric weight loss measurement. The results thus obtained indicate that the addition of inhibitors enhances the corrosion resistance properties.

  10. A novel histone deacetylase 1 and 2 isoform-specific inhibitor alleviates experimental Parkinson's disease.

    PubMed

    Choong, Chi-Jing; Sasaki, Tsutomu; Hayakawa, Hideki; Yasuda, Toru; Baba, Kousuke; Hirata, Yoshiyuki; Uesato, Shinichi; Mochizuki, Hideki

    2016-01-01

    With increased histone deacetylase (HDAC) activity and histone hypoacetylation being implicated in neurodegeneration, HDAC inhibitors have been reported to have considerable therapeutic potential. Yet, existing inhibitors lack specificity and may show substantial adverse effect. In this study, we identified a novel HDAC1/2 isoform-specific inhibitor, K560, with protective effects against 1-methyl-4-phenylpyridinium (MPP(+))- and/or 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced neuronal death in both in vitro and in vivo Parkinson's disease model. K560 attenuated cell death induced by MPP(+) in differentiated SH-SY5Y cells through the sustained expression of an antiapoptotic protein, X-linked inhibitor of apoptosis (XIAP). Inhibition of XIAP expression by locked nucleic acid antisense oligonucleotides abolished the protective effect of K560. Inactivation of mitogen-activated protein kinase cascades, reduced p53 phosphorylation, and down-regulation of p53-upregulated modulator of apoptosis on K560 treatment were also observed. Furthermore, pre- and post-oral administration of K560 to mice prevented MPTP-induced loss of dopaminergic neurons in substantia nigra, suggesting that selective inhibition of HDAC1 and HDAC2 by K560 may pave the way to new strategies for Parkinson's disease treatment.

  11. Corrosion protection of equipment in recirculating water supply systems

    SciTech Connect

    Teslya, B.M.; Burlov, V.V.; Shadrina, A.N.; Vyazhevich, A.V.

    1983-01-01

    The metals in the condensers, coolers and heat exchangers of petroleum refineries and petrochemical plants are subject to corrosion, and this is responsible for forced shutdowns. This paper notes that the shortest service life is given by the carbon and silicon-manganese steels, the longest by the chrome-nickel steels and arsenic-alloyed brasses. It reports that a high level of protection is provided by the use of the inhibitor IKB-4V at the Industrial Association ''Novopolotsknefteorgsintez'' and a so-called complex corrosion retarder consisting of a mixture of zinc sulfate and orthophosphoric acid at the Novo-Ufa refinery. It also points out that the most desirable method for corrosion protection of cooling towers, from the standpoint of technical and economic justification, is the use of protective paint coatings. It urges scientific research and design organizations and also the plants of the petroleum refining and petrochemical industry to take a multipronged approach in solving problems in corrosion control. It is pointed out that protection by inhibitors must be combined with the use of paints and other types of organic and inorganic coatings, protection against salt deposition and biological overgrowth, and the rational use of corrosion-resistant materials of construction.

  12. Diffusion Coatings as Corrosion Inhibitors

    NASA Astrophysics Data System (ADS)

    Ivanov, Radoslav; Ignatova-Ivanova, Tsveteslava

    2016-03-01

    Corrosion is the cause of irretrievable loss of huge amounts of metals and alloys. The harmful effects of corrosion can be reduced significantly by applying appropriate methods of corrosion protection. One method to protect metals against corrosion is the formation of diffusion coatings on them. High corrosion resistance is typical for the boride diffusion layers. Aluminothermy is one of the main methods for diffusion saturation of the surface of metal products with various elements, including boron, and under certain conditions with aluminum, too. Samples of steel 45 were put to aluminothermic diffusion saturation with boron in a pressurized steel container at a temperature of 1100K, for 6 hours in powdered aluminothermic mixtures. The content of B2O3 in the starting mixtures decreased from the optimum - 20% to 0%, and the content of Al and the activator - (NH4)2.4BF3 is constant, respectively 7% and 0.5%. Al2O3 was used as filler. The borided samples were tested for corrosion resistance in 10% HCl for 72 hours. The results show that their corrosion resistance depends on the composition of the starting saturating mixture (mainly on the content of B2O3), and respectively on the composition, structure, thickness and degree of adhesion of the layer to the metal base.

  13. Antidotes to anthrax lethal factor intoxication. Part 1: Discovery of potent lethal factor inhibitors with in vivo efficacy.

    PubMed

    Jiao, Guan-Sheng; Kim, Seongjin; Moayeri, Mahtab; Cregar-Hernandez, Lynne; McKasson, Linda; Margosiak, Stephen A; Leppla, Stephen H; Johnson, Alan T

    2010-11-15

    Sub-nanomolar small molecule inhibitors of anthrax lethal factor have been identified using SAR and Merck L915 (4) as a model compound. One of these compounds (16) provided 100% protection in a rat lethal toxin model of anthrax disease.

  14. The effects of direct renin inhibitor, aliskiren, on arterial hypertension, chronic kidney disease and cardiovascular disease: optimal pharmacotherapy.

    PubMed

    Morishita, Yoshiyuki; Kusano, Eiji

    2013-03-01

    The renin-angiotensin-aldosterone system (RAAS) plays pivotal roles in the pathogenesis of progression of arterial hypertension, chronic kidney disease (CKD) and cardiovascular disease (CVD). Previous studies suggested that a direct renin inhibitor, aliskiren, may be effective for blood pressure lowering, renoprotection and cardiovascular protection. This review focuses on the effects of aliskiren for arterial hypertension, CKD and CVD.

  15. Effect of B-Mo-W Complex Inhibitor on Corrosion of Mild Steel in 55% LiBr Solution

    NASA Astrophysics Data System (ADS)

    Li, Jielan; Liang, Chenghao; Huang, Naibao

    2015-11-01

    The inhibition effects of B-Mo-W complex inhibitor on corrosion of mild steel in 55% LiBr solution were investigated using weight-loss method, electrochemistry tests, SEM, EDX, and XRD. The ingredients of B-Mo-W complex inhibitor included organic phosphonic acid B, Na2MoO4, and Na2WO4. The results revealed that B-Mo-W complex inhibitor was capable of inhibiting the corrosion of mild steel in 55% LiBr solution, exhibiting high inhibition efficiencies around 97.7%. B-Mo-W complex inhibitor promoted the formation of a protective passive film composed of Fe, Mo, W, and O elements. The passive film decreased the corrosion rate, improved the electrochemistry performance, and enhanced anti-corrosion ability of mild steel.

  16. Corrosion mitigation of N-(2-hydroxy-3-trimethyl ammonium)propyl chitosan chloride as inhibitor on mild steel.

    PubMed

    Sangeetha, Y; Meenakshi, S; SairamSundaram, C

    2015-01-01

    The biopolymer N-(2-hydroxy-3-trimethyl ammonium)propyl chitosan chloride (HTACC) was synthesised and its influence as a novel corrosion inhibitor on mild steel in 1M HCl was studied using gravimetric and electrochemical experiments. The compound obtained was characterised using FTIR and NMR studies. The inhibition efficiency increased with the increase in concentration and reached a maximum of 98.9% at 500 ppm concentration. Polarisation studies revealed that HTACC acts both as anodic and cathodic inhibitor. Electrochemical impedance studies confirmed that the inhibition is through adsorption on the metal surface. The extent of inhibition exhibits a negative trend with increase in temperature. Langmuir isotherm provides the best description on the adsorption nature of the inhibitor. SEM analysis indicated the presence of protective film formed by the inhibitor on the metal surface.

  17. [Use of corrosion inhibitors during the sterilization and disinfection of medical instruments].

    PubMed

    Talalina, A S; Kochanova, L G; Anan'eva, A I; Romanova, A A

    1984-01-01

    The search of corrosion inhibitors reducing the corrosive action of the sterilizing and disinfecting media has been performed in order to protect instruments made of metals against corrosion during these processes. The program of the investigations includes potentiodynamic and potentiostatic measurements and full-scale tests. The infection of the sodium benzoate or potassium gluconate into the disinfecting chloramine solution and sterilizing hydrogene peroxide solution has been shown to improve the resistance to the corrosion for medical instruments made of carbon steel.

  18. The synthesis of ethacrynic acid thiazole derivatives as glutathione S-transferase pi inhibitors.

    PubMed

    Li, Ting; Liu, Guyue; Li, Hongcai; Yang, Xinmei; Jing, Yongkui; Zhao, Guisen

    2012-04-01

    Glutathione S-transferase pi (GSTpi) is a phase II enzyme which protects cells from death and detoxifies chemotherapeutic agents in cancer cells. Ethacrynic acid (EA) is a weak GSTpi inhibitor. Structure modifications were done to improve the ability of EA to inhibit GSTpi activity. Eighteen EA thiazole derivatives were designed and synthesized. Compounds 9a, 9b and 9c with a replacement of carboxyl group of EA by a heterocyclic thiazole exhibited improvement over EA to inhibit GSTpi activity.

  19. Photosensitive dissolution inhibitors and resists based on onium salt carboxylates

    DOEpatents

    Dentinger, Paul M.; Simison, Kelby L.

    2005-11-29

    A photoresist composition that employs onium salt carboxylates as thermally stable dissolution inhibitors. The photoresist composition can be either an onium carboxylate salt with a phenolic photoresist, such as novolac, or an onium cation protected carboxylate-containing resin such as an acrylic/acrylic acid copolymer. The onium carboxylate can be an onium cholate, wherein the onium cholate is an iodonium cholate. Particularly preferred iodonium cholates are alkyloxyphenylphenyl iodonium cholates and most particularly preferred is octyloxyphenyphenyl iodonium cholate. The photoresist composition will not create nitrogen or other gaseous byproducts upon exposure to radiation, does not require water for photoactivation, has acceptable UV radiation transmission characteristics, and is thermally stable at temperatures required for solvent removal.

  20. Photoactivatable Caged Prodrugs of VEGFR-2 Kinase Inhibitors.

    PubMed

    Pinchuk, Boris; Horbert, Rebecca; Döbber, Alexander; Kuhl, Lydia; Peifer, Christian

    2016-04-29

    In this study, we report on the design, synthesis, photokinetic properties and in vitro evaluation of photoactivatable caged prodrugs for the receptor tyrosine kinase VEGFR-2. Highly potent VEGFR-2 inhibitors 1 and 3 were caged by introduction of a photoremovable protecting group (PPG) to yield the caged prodrugs 4 and 5. As expected, enzymatic and cellular proliferation assays showed dramatically diminished efficacy of caged prodrugs in vitro. Upon ultraviolet (UV) irradiation of the prodrugs original inhibitory activity was completely restored and even distinctly reinforced, as was the case for the prodrug 4. The presented results are a further evidence for caging technique being an interesting approach in the protein kinase field. It could enable spatial and temporal control for the inhibition of VEGFR-2. The described photoactivatable prodrugs might be highly useful as biological probes for studying the VEGFR-2 signal transduction.