Interannual variability of terrestrial NEP and its attributions to carbon uptake amplitude and period

NASA Astrophysics Data System (ADS)

Niu, S.

2015-12-01

Earth system exhibits strong interannual variability (IAV) in the global carbon cycle as reflected in the year-to-year anomalies of the atmospheric CO2 concentration. Although various analyses suggested that land ecosystems contribute mostly to the IAV of atmospheric CO2 concentration, processes leading to the IAV in the terrestrial carbon (C) cycle are far from clear and hinder our effort in predicting the IAV of global C cycle. Previous studies on IAV of global C cycle have focused on the regulation of climatic variables in tropical or semiarid areas, but generated inconsistent conclusions. Using long-term eddy-flux measurements of net ecosystem production (NEP), atmospheric CO2 inversion NEP, and the MODIS-derived gross primary production (GPP), we demonstrate that seasonal carbon uptake amplitude (CUA) and period (CUP) are two key processes that control the IAV in the terrestrial C cycle. The two processes together explain 78% of the variations in the IAV in eddy covariance NEP, 70% in global atmospheric inversed NEP, and 53% in the IAV of GPP. Moreover, the three lines of evidence consistently show that variability in CUA is much more important than that of CUP in determining the variation of NEP at most eddy-flux sites, and most grids of global NEP and GPP. Our results suggest that the maximum carbon uptake potential in the peak-growing season is a determinant process of global C cycle internnual variability and carbon uptake period may play less important role than previous expectations. This study uncovers the most parsimonious, proximate processes underlying the IAV in global C cycle of the Earth system. Future research is needed to identify how climate factors affect the IAV in terrestrial C cycle through their influence on CUA and CUP.

New function for an old enzyme: NEP deficient mice develop late-onset obesity.

PubMed

Becker, Matthias; Siems, Wolf-Eberhard; Kluge, Reinhart; Gembardt, Florian; Schultheiss, Heinz-Peter; Schirner, Michael; Walther, Thomas

2010-09-16

According to the World Health Organization (WHO) there is a pandemic of obesity with approximately 300 million people being obese. Typically, human obesity has a polygenetic causation. Neutral endopeptidase (NEP), also known as neprilysin, is considered to be one of the key enzymes in the metabolism of many active peptide hormones. An incidental observation in NEP-deficient mice was a late-onset excessive gain in body weight exclusively from a ubiquitous accumulation of fat tissue. In accord with polygenetic human obesity, mice were characterized by deregulation of lipid metabolism, higher blood glucose levels, with impaired glucose tolerance. The key role of NEP in determining body mass was confirmed by the use of the NEP inhibitor candoxatril in wild-type mice that increased body weight due to increased food intake. This is a peripheral and not a central NEP action on the switch for appetite control, since candoxatril cannot cross the blood-brain barrier. Furthermore, we demonstrated that inhibition of NEP in mice with cachexia delayed rapid body weight loss. Thus, lack in NEP activity, genetically or pharmacologically, leads to a gain in body fat. In the present study, we have identified NEP to be a crucial player in the development of obesity. NEP-deficient mice start to become obese under a normocaloric diet in an age of 6-7 months and thus are an ideal model for the typical human late-onset obesity. Therefore, the described obesity model is an ideal tool for research on development, molecular mechanisms, diagnosis, and therapy of the pandemic obesity.

New Function for an Old Enzyme: NEP Deficient Mice Develop Late-Onset Obesity

PubMed Central

Becker, Matthias; Siems, Wolf-Eberhard; Kluge, Reinhart; Gembardt, Florian; Schultheiss, Heinz-Peter; Schirner, Michael; Walther, Thomas

2010-01-01

Background According to the World Health Organization (WHO) there is a pandemic of obesity with approximately 300 million people being obese. Typically, human obesity has a polygenetic causation. Neutral endopeptidase (NEP), also known as neprilysin, is considered to be one of the key enzymes in the metabolism of many active peptide hormones. Methodology/Principal Findings An incidental observation in NEP-deficient mice was a late-onset excessive gain in body weight exclusively from a ubiquitous accumulation of fat tissue. In accord with polygenetic human obesity, mice were characterized by deregulation of lipid metabolism, higher blood glucose levels, with impaired glucose tolerance. The key role of NEP in determining body mass was confirmed by the use of the NEP inhibitor candoxatril in wild-type mice that increased body weight due to increased food intake. This is a peripheral and not a central NEP action on the switch for appetite control, since candoxatril cannot cross the blood-brain barrier. Furthermore, we demonstrated that inhibition of NEP in mice with cachexia delayed rapid body weight loss. Thus, lack in NEP activity, genetically or pharmacologically, leads to a gain in body fat. Conclusions/Significance In the present study, we have identified NEP to be a crucial player in the development of obesity. NEP-deficient mice start to become obese under a normocaloric diet in an age of 6–7 months and thus are an ideal model for the typical human late-onset obesity. Therefore, the described obesity model is an ideal tool for research on development, molecular mechanisms, diagnosis, and therapy of the pandemic obesity. PMID:20862277

The opposing effects of calmodulin, adenosine 5 prime -triphosphate, and pertussis toxin on phorbol ester induced inhibition of atrial natriuretic factor stimulated guanylate cyclase in SK-NEP-1 cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sekiya, M.; Frohlich, E.D.; Cole, F.E.

1991-01-01

In the present study, we investigated the effects of calmodulin, adenosine 5{prime}-triphosphate (ATP) and pertussis toxin (PT) on phorbol ester (PMA) induced inhibition of ANF-stimulated cyclic GMP formation in cells from the human renal cell line, SK-NEP-1. PMA inhibited ANF-stimulated guanylate cyclase activity in particulate membranes by about 65%. Calmodulin reversed this inhibition in a dose dependent manner. ATP potentiated Mg++ but not Mn++ supported guanylate cyclase activity. In PMA treated membranes, ATP potentiating effects were abolished. PMA also inhibited ANF-stimulated cGMP accumulation, but pretreatment with PT prevented this PMA inhibition. PT did not affect basal or ANF-stimulated cGMP accumulation.more » In conclusion, these results demonstrated that PMA inhibited ANF stimulation of particulate guanylate cyclase in opposition to the activating effects of calmodulin or ATP in SK-NEP-1 cells. The protein kinase C inhibitory effects appeared to be mediated via a PT-sensitive G protein.« less

Record Low NEP in the Hot-Electron Titanium Nanobolometers

NASA Technical Reports Server (NTRS)

Karasik, Boris S.; Olaya, David; Wei, Jian; Pereverzev, Sergey; Gershenson, Michael E.; Kawamura, Jonathan H.; McGrath, William R.; Sergeev, Andrei V.

2006-01-01

We are developing hot-electron superconducting transition-edge sensors (TES) capable of counting THz photons and operating at T = 0.3K. We fabricated superconducting Ti nanosensors with Nb contacts with a volume of approx. 3x10(exp -3) cu microns on planar Si substrate and have measured the thermal conductance due to the weak electron-phonon coupling in the material G = 4x10(exp -14) W/K at 0.3 K. The corresponding phonon-noise NEP = 3x10(exp -19) W/Hz(sup 1/2). Detection of single optical photons (1550nm and 670nm wavelength) has been demonstrated for larger devices and yielded the thermal time constants of 30 microsec at 145 mK and of 25 microsec at 190 mK. This Hot-Electron Direct Detector (HEDD) is expected to have a sufficient energy resolution for detecting individual photons with (nu) > 1 THz where NEP approx. 3x10(exp -20) W/Hz(sup 1/2) is needed for spectroscopy in space.

Inhibitory effect of morphine on granulocyte stimulation by tumor necrosis factor and substance P.

PubMed

Stefano, G B; Kushnerik, V; Rodriquez, M; Bilfinger, T V

1994-04-01

We demonstrate that morphine, at higher concentrations than that effective in the inhibition of spontaneously active cells, can antagonize stimulation of human granulocytes by tumor necrosis factor (TNF) or substance P. The antagonistic effect appears to occur indirectly by way of downregulation of the cells' responsiveness to these stimulatory substances. We have previously shown that neutral endopeptidase 24.11 (NEP) is an important enzyme in neuro- and autoimmunoregulation of both vertebrates and invertebrates, and that activation of human granulocytes by monokines and neuropeptides results in regulation of NEP. Exposure of intact human granulocytes to morphine increases NEP by a naloxone-sensitive mechanism. The increased expression of NEP downregulates the stimulatory effect of substance P and TNF. In the case of substance P, we demonstrate the significance of NEP in modulating the process of downregulation by use of a specific NEP inhibitor, phosphoramidon. These results indicate that morphine is a significant factor in downregulating immunocyte responsiveness to NEP substrates and also to those signal molecules (i.e. cytokines) not metabolized by it. In summary, we infer that opiates may be endogenous signal molecules, a status that appears to be amply supported by their immunosuppressive actions.

Transfection of influenza A virus nuclear export protein induces the expression of tumor necrosis factor alpha.

PubMed

Lara-Sampablo, Alejandra; Flores-Alonso, Juan Carlos; De Jesús-Ortega, Nereyda; Santos-López, Gerardo; Vallejo-Ruiz, Verónica; Rosas-Murrieta, Nora; Reyes-Carmona, Sandra; Herrera-Camacho, Irma; Reyes-Leyva, Julio

2014-06-24

Influenza A virus genomic segments eight codes for non-structural 1 (NS1) protein that is involved in evasion of innate antiviral response, and nuclear export protein (NEP) that participates in the export of viral ribonucleoprotein (RNP) complexes, transcription and replication. Tumor necrosis factor alpha (TNF-α) is highly expressed during influenza virus infections and is considered an anti-infective cytokine. NS1 and NEP proteins were overexpressed and their role on TNF-α expression was evaluated. Both TNF-α mRNA and protein increased in cells transfected with NEP but not with NS1. We further investigate if NS1 or NEP regulates the activity of TNF-α promoter. In the presence of NEP the activity of TNF-α promoter increased significantly compared with the control (83.5±2.9 vs. 30.9±2.8, respectively; p=0.001). This effect decreased 15-fold when the TNF-α promoter distal region was deleted, suggesting the involvement of mitogen-activated protein kinases (MAPK) and NF-kB response elements. This was corroborated by testing the effect produced on TNF-α promoter by the treatment with Raf/MEK/ERK (U0126), NF-kB (Bay-11-7082) and PI3K (Ly294-002) cell signaling inhibitors. Treatment with U0126 and Bay-117082 reduced the activity of TNF-α promoter mediated by NEP (41.5±3.2, 70% inhibition; and 80.6±7.4, 35% inhibition, respectively) compared to mock-treated control. The results suggest a new role for NEP protein that participates in the transcriptional regulation of human TNF-α expression. Copyright © 2014 Elsevier B.V. All rights reserved.

Overview of North Ecliptic Pole Deep Multi-Wavelength Survey Nep-Deep

NASA Astrophysics Data System (ADS)

Matsuhara, H.; Wada, T.; Oi, N.; Takagi, T.; Nakagawa, T.; Murata, K.; Goto, T.; Oyabu, S.; Takeuchi, T. T.; Malek, K.; Solarz, A.; Ohyama, Y.; Miyaji, T.; Krumpe, M.; Lee, H. M.; Im, M.; Serjeant, S.; Pearson, C. P.; White, G. J.; Malkan, M. A.; Hanami, H.; Ishigaki, T.; Burgarella, D.; Buat, V.; Pollo, A.

2017-03-01

The recent updates of the North Ecliptic Pole deep (0.5~deg$^2$, NEP-Deep) multi-wavelength survey covering from X-ray to radio-wave is presented. The NEP-Deep provides us with several thousands of 15~$\\mu$m or 18~$\\mu$m selected sample of galaxies, which is the largest sample ever made at this wavelengths. A continuous filter coverage in the mid-infrared wavelength (7, 9, 11, 15, 18, and 24~$\\mu$m) is unique and vital to diagnose the contributions from starbursts and AGNs in the galaxies out to $z$=2.The new goal of the project is to resolve the nature of the cosmic star formation history at the violent epoch (e.g. $z$=1--2), and to find a clue to understand its decline from $z$=1 to present universe by utilizing the unique power of the multi-wavelength survey. The progress in this context is briefly mentioned.

Expression of an oxalate decarboxylase impairs the necrotic effect induced by Nep1-like protein (NLP) of Moniliophthora perniciosa in transgenic tobacco.

PubMed

da Silva, Leonardo F; Dias, Cristiano V; Cidade, Luciana C; Mendes, Juliano S; Pirovani, Carlos P; Alvim, Fátima C; Pereira, Gonçalo A G; Aragão, Francisco J L; Cascardo, Júlio C M; Costa, Marcio G C

2011-07-01

Oxalic acid (OA) and Nep1-like proteins (NLP) are recognized as elicitors of programmed cell death (PCD) in plants, which is crucial for the pathogenic success of necrotrophic plant pathogens and involves reactive oxygen species (ROS). To determine the importance of oxalate as a source of ROS for OA- and NLP-induced cell death, a full-length cDNA coding for an oxalate decarboxylase (FvOXDC) from the basidiomycete Flammulina velutipes, which converts OA into CO(2) and formate, was overexpressed in tobacco plants. The transgenic plants contained less OA and more formic acid compared with the control plants and showed enhanced resistance to cell death induced by exogenous OA and MpNEP2, an NLP of the hemibiotrophic fungus Moniliophthora perniciosa. This resistance was correlated with the inhibition of ROS formation in the transgenic plants inoculated with OA, MpNEP2, or a combination of both PCD elicitors. Taken together, these results have established a pivotal function for oxalate as a source of ROS required for the PCD-inducing activity of OA and NLP. The results also indicate that FvOXDC represents a potentially novel source of resistance against OA- and NLP-producing pathogens such as M. perniciosa, the causal agent of witches' broom disease of cacao (Theobroma cacao L.).

Neprilysin and Aβ Clearance: Impact of the APP Intracellular Domain in NEP Regulation and Implications in Alzheimer’s Disease

PubMed Central

Grimm, Marcus O. W.; Mett, Janine; Stahlmann, Christoph P.; Haupenthal, Viola J.; Zimmer, Valerie C.; Hartmann, Tobias

2013-01-01

One of the characteristic hallmarks of Alzheimer’s disease (AD) is an accumulation of amyloid β (Aβ) leading to plaque formation and toxic oligomeric Aβ complexes. Besides the de novo synthesis of Aβ caused by amyloidogenic processing of the amyloid precursor protein (APP), Aβ levels are also highly dependent on Aβ degradation. Several enzymes are described to cleave Aβ. In this review we focus on one of the most prominent Aβ degrading enzymes, the zinc-metalloprotease Neprilysin (NEP). In the first part of the review we discuss beside the general role of NEP in Aβ degradation the alterations of the enzyme observed during normal aging and the progression of AD. In vivo and cell culture experiments reveal that a decreased NEP level results in an increased Aβ level and vice versa. In a pathological situation like AD, it has been reported that NEP levels and activity are decreased and it has been suggested that certain polymorphisms in the NEP gene result in an increased risk for AD. Conversely, increasing NEP activity in AD mouse models revealed an improvement in some behavioral tests. Therefore it has been suggested that increasing NEP might be an interesting potential target to treat or to be protective for AD making it indispensable to understand the regulation of NEP. Interestingly, it is discussed that the APP intracellular domain (AICD), one of the cleavage products of APP processing, which has high similarities to Notch receptor processing, might be involved in the transcriptional regulation of NEP. However, the mechanisms of NEP regulation by AICD, which might be helpful to develop new therapeutic strategies, are up to now controversially discussed and summarized in the second part of this review. In addition, we review the impact of AICD not only in the transcriptional regulation of NEP but also of further genes. PMID:24391587

Moniliophthora perniciosa necrosis- and ethylene-inducing protein 2 (MpNep2) as a metastable dimer in solution: structural and functional implications.

PubMed

de Oliveira, Guilherme A P; Pereira, Elen G; Dias, Cristiano V; Souza, Theo L F; Ferretti, Giulia D S; Cordeiro, Yraima; Camillo, Luciana R; Cascardo, Júlio; Almeida, Fabio C; Valente, Ana Paula; Silva, Jerson L

2012-01-01

Understanding how Nep-like proteins (NLPs) behave during the cell cycle and disease progression of plant pathogenic oomycetes, fungi and bacteria is crucial in light of compelling evidence that these proteins play a role in Witches` Broom Disease (WBD) of Theobroma cacao, one of the most important phytopathological problems to afflict the Southern Hemisphere. The crystal structure of MpNep2, a member of the NLP family and the causal agent of WBD, revealed the key elements for its activity. This protein has the ability to refold after heating and was believed to act as a monomer in solution, in contrast to the related homologs MpNep1 and NPP from the oomyceteous fungus Phytophthora parasitica. Here, we identify and characterize a metastable MpNep2 dimer upon over-expression in Escherichia coli using different biochemical and structural approaches. We found using ultra-fast liquid chromatography that the MpNep2 dimer can be dissociated by heating but not by dilution, oxidation or high ionic strength. Small-angle X-ray scattering revealed a possible tail-to-tail interaction between monomers, and nuclear magnetic resonance measurements identified perturbed residues involved in the putative interface of interaction. We also explored the ability of the MpNep2 monomer to refold after heating or chemical denaturation. We observed that MpNep2 has a low stability and cooperative fold that could be an explanation for its structure and activity recovery after stress. These results can provide new insights into the mechanism for MpNep2's action in dicot plants during the progression of WBD and may open new avenues for the involvement of NLP- oligomeric species in phytopathological disorders.

NEP: web server for epitope prediction based on antibody neutralization of viral strains with diverse sequences

PubMed Central

Chuang, Gwo-Yu; Liou, David; Kwong, Peter D.; Georgiev, Ivelin S.

2014-01-01

Delineation of the antigenic site, or epitope, recognized by an antibody can provide clues about functional vulnerabilities and resistance mechanisms, and can therefore guide antibody optimization and epitope-based vaccine design. Previously, we developed an algorithm for antibody-epitope prediction based on antibody neutralization of viral strains with diverse sequences and validated the algorithm on a set of broadly neutralizing HIV-1 antibodies. Here we describe the implementation of this algorithm, NEP (Neutralization-based Epitope Prediction), as a web-based server. The users must supply as input: (i) an alignment of antigen sequences of diverse viral strains; (ii) neutralization data for the antibody of interest against the same set of antigen sequences; and (iii) (optional) a structure of the unbound antigen, for enhanced prediction accuracy. The prediction results can be downloaded or viewed interactively on the antigen structure (if supplied) from the web browser using a JSmol applet. Since neutralization experiments are typically performed as one of the first steps in the characterization of an antibody to determine its breadth and potency, the NEP server can be used to predict antibody-epitope information at no additional experimental costs. NEP can be accessed on the internet at http://exon.niaid.nih.gov/nep. PMID:24782517

Moniliophthora perniciosa Necrosis- and Ethylene-Inducing Protein 2 (MpNep2) as a Metastable Dimer in Solution: Structural and Functional Implications

PubMed Central

de Oliveira, Guilherme A. P.; Pereira, Elen G.; Dias, Cristiano V.; Souza, Theo L. F.; Ferretti, Giulia D. S.; Cordeiro, Yraima; Camillo, Luciana R.; Almeida, Fabio C.; Valente, Ana Paula; Silva, Jerson L.

2012-01-01

Understanding how Nep-like proteins (NLPs) behave during the cell cycle and disease progression of plant pathogenic oomycetes, fungi and bacteria is crucial in light of compelling evidence that these proteins play a role in Witches` Broom Disease (WBD) of Theobroma cacao, one of the most important phytopathological problems to afflict the Southern Hemisphere. The crystal structure of MpNep2, a member of the NLP family and the causal agent of WBD, revealed the key elements for its activity. This protein has the ability to refold after heating and was believed to act as a monomer in solution, in contrast to the related homologs MpNep1 and NPP from the oomyceteous fungus Phytophthora parasitica. Here, we identify and characterize a metastable MpNep2 dimer upon over-expression in Escherichia coli using different biochemical and structural approaches. We found using ultra-fast liquid chromatography that the MpNep2 dimer can be dissociated by heating but not by dilution, oxidation or high ionic strength. Small-angle X-ray scattering revealed a possible tail-to-tail interaction between monomers, and nuclear magnetic resonance measurements identified perturbed residues involved in the putative interface of interaction. We also explored the ability of the MpNep2 monomer to refold after heating or chemical denaturation. We observed that MpNep2 has a low stability and cooperative fold that could be an explanation for its structure and activity recovery after stress. These results can provide new insights into the mechanism for MpNep2′s action in dicot plants during the progression of WBD and may open new avenues for the involvement of NLP- oligomeric species in phytopathological disorders. PMID:23029140

Fracture network evaluation program (FraNEP): A software for analyzing 2D fracture trace-line maps

NASA Astrophysics Data System (ADS)

Zeeb, Conny; Gomez-Rivas, Enrique; Bons, Paul D.; Virgo, Simon; Blum, Philipp

2013-10-01

Fractures, such as joints, faults and veins, strongly influence the transport of fluids through rocks by either enhancing or inhibiting flow. Techniques used for the automatic detection of lineaments from satellite images and aerial photographs, LIDAR technologies and borehole televiewers significantly enhanced data acquisition. The analysis of such data is often performed manually or with different analysis software. Here we present a novel program for the analysis of 2D fracture networks called FraNEP (Fracture Network Evaluation Program). The program was developed using Visual Basic for Applications in Microsoft Excel™ and combines features from different existing software and characterization techniques. The main novelty of FraNEP is the possibility to analyse trace-line maps of fracture networks applying the (1) scanline sampling, (2) window sampling or (3) circular scanline and window method, without the need of switching programs. Additionally, binning problems are avoided by using cumulative distributions, rather than probability density functions. FraNEP is a time-efficient tool for the characterisation of fracture network parameters, such as density, intensity and mean length. Furthermore, fracture strikes can be visualized using rose diagrams and a fitting routine evaluates the distribution of fracture lengths. As an example of its application, we use FraNEP to analyse a case study of lineament data from a satellite image of the Oman Mountains.

Hyper Suprime-Camera Survey of the Akari NEP Wide Field

NASA Astrophysics Data System (ADS)

Goto, Tomotsugu; Toba, Yoshiki; Utsumi, Yousuke; Oi, Nagisa; Takagi, Toshinobu; Malkan, Matt; Ohayma, Youichi; Murata, Kazumi; Price, Paul; Karouzos, Marios; Matsuhara, Hideo; Nakagawa, Takao; Wada, Takehiko; Serjeant, Steve; Burgarella, Denis; Buat, Veronique; Takada, Masahiro; Miyazaki, Satoshi; Oguri, Masamune; Miyaji, Takamitsu; Oyabu, Shinki; White, Glenn; Takeuchi, Tsutomu; Inami, Hanae; Perason, Chris; Malek, Katarzyna; Marchetti, Lucia; Lee, Hyung Mok; Im, Myung; Kim, Seong Jin; Koptelova, Ekaterina; Chao, Dani; Wu, Yi-Han; AKARI NEP Survey Team; AKARI All Sky Survey Team

2017-03-01

The extragalactic background suggests half the energy generated by stars was reprocessed into the infrared (IR) by dust. At z ∼1.3, 90% of star formation is obscured by dust. To fully understand the cosmic star formation history, it is critical to investigate infrared emission. AKARI has made deep mid-IR observation using its continuous 9-band filters in the NEP field (5.4 deg^2), using ∼10% of the entire pointed observations available throughout its lifetime. However, there remain 11,000 AKARI infrared sources undetected with the previous CFHT/Megacam imaging (r ∼25.9ABmag). Redshift and IR luminosity of these sources are unknown. These sources may contribute significantly to the cosmic star-formation rate density (CSFRD). For example, if they all lie at 1 < z < 2, the CSFRD will be twice as high at the epoch. We are carrying out deep imaging of the NEP field in 5 broad bands (g,r,i,z, and y) using Hyper Suprime-Camera (HSC), which has 1.5 deg field of view in diameter on Subaru 8m telescope. This will provide photometric redshift information, and thereby IR luminosity for the previously-undetected 11,000 faint AKARI IR sources. Combined with AKARI's mid-IR AGN/SF diagnosis, and accurate mid-IR luminosity measurement, this will allow a complete census of cosmic star-formation/AGN accretion history obscured by dust.

Patterns of NPP, GPP, Respiration and NEP During Boreal Forest Succession

DOE Office of Scientific and Technical Information (OSTI.GOV)

Goulden, Michael L.; McMillan, Andrew; Winston, Greg

2010-12-15

We deployed a mesonet of year-round eddy covariance towers in boreal forest stands that last burned in ~1850, ~1930, 1964, 1981, 1989, 1998, and 2003 to understand how CO2 exchange changes during secondary succession.The strategy of using multiple methods, including biometry and micrometeorology, worked well. In particular, the three independent measures of NEP during succession gave similar results. A stratified and tiered approach to deploying eddy covariance systems that combines many lightweight and portable towers with a few permanent ones is likely to maximize the science return for a fixed investment. The existing conceptual models did a good job ofmore » capturing the dominant patterns of NPP, GPP, Respiration and NEP during succession. The initial loss of carbon following disturbance was neither as protracted nor large as predicted. This muted response reflects both the rapid regrowth of vegetation following fire and the prevalence of standing coarse woody debris following the fire, which is thought to decay slowly. In general, the patterns of forest recovery from disturbance should be expected to vary as a function of climate, ecosystem type and disturbance type. The NPP decline at the older stands appears related to increased Rauto rather than decreased GPP. The increase in Rauto in the older stands does not appear to be caused by accelerated maintenance respiration with increased biomass, and more likely involves increased allocation to fine root turnover, root metabolism, alternative forms of respiration, mycorrhizal relationships, or root exudates, possibly associated with progressive nutrient limitation. Several studies have now described a similar pattern of NEP following boreal fire, with 10-to-15 years of modest carbon loss followed by 50-to-100 years of modest carbon gain. This trend has been sufficiently replicated and evaluated using independent techniques that it can be used to quantify the likely effects of changes in boreal fire frequency

NEP: web server for epitope prediction based on antibody neutralization of viral strains with diverse sequences.

PubMed

Chuang, Gwo-Yu; Liou, David; Kwong, Peter D; Georgiev, Ivelin S

2014-07-01

Delineation of the antigenic site, or epitope, recognized by an antibody can provide clues about functional vulnerabilities and resistance mechanisms, and can therefore guide antibody optimization and epitope-based vaccine design. Previously, we developed an algorithm for antibody-epitope prediction based on antibody neutralization of viral strains with diverse sequences and validated the algorithm on a set of broadly neutralizing HIV-1 antibodies. Here we describe the implementation of this algorithm, NEP (Neutralization-based Epitope Prediction), as a web-based server. The users must supply as input: (i) an alignment of antigen sequences of diverse viral strains; (ii) neutralization data for the antibody of interest against the same set of antigen sequences; and (iii) (optional) a structure of the unbound antigen, for enhanced prediction accuracy. The prediction results can be downloaded or viewed interactively on the antigen structure (if supplied) from the web browser using a JSmol applet. Since neutralization experiments are typically performed as one of the first steps in the characterization of an antibody to determine its breadth and potency, the NEP server can be used to predict antibody-epitope information at no additional experimental costs. NEP can be accessed on the internet at http://exon.niaid.nih.gov/nep. Published by Oxford University Press on behalf of Nucleic Acids Research 2014. This work is written by (a) US Government employee(s) and is in the public domain in the US.

TcCYS4, a cystatin from cocoa, reduces necrosis triggered by MpNEP2 in tobacco plants.

PubMed

Santana, L S; Costa, M G C; Pirovani, N M; Almeida, A F; Alvim, F C; Pirovani, C P

2014-09-26

In Brazil, most cocoa bean production occurs in Southern Bahia. Witches' broom disease arrived in this area in 1989 and has since caused heavy losses in production. The disease is caused by the basidiomycete fungus Moniliophthora perniciosa, a hemibiotrophic fungus that produces the necrosis and ethylene-inducting protein (MpNEP2) during infection; this protein can activate cysteine proteases and induce programmed cell death. Cysteine proteases can be modulated by cystatin. In this study, we overexpressed TcCYS4, a cocoa cystatin, in tobacco plants and evaluated the effect on MpNEP2 in model plants. Tccys4 cDNA was cloned into the pCAMBIA 1390 vector and inserted into the tobacco plants via Agrobacterium tumefaciens. Transgene expression was analyzed by reverse transcription-quantitative PCR and Western blot analysis. Transcript and protein levels in Tcccys4:tobacco lines were 8.9- and 1.5-fold higher than in wild-type plants (wt). Tcccys4:tobacco lines showed no change in growth compared to wt plants. CO2 net assimilation (A) increased in Tcccys4:tobacco lines compared to wt plants. Only one line showed statistically significant stomatal conductance (gs) and transpiration rate (E) changes. MpNEP2 was infiltered into the foliar mesophyll of Tcccys4:tobacco lines and wt plants, and necrotic lesions were attenuated in lines highly expressing Tccys4. Our results suggest that cocoa cystatin TcCYS4 affects MpNEP2 activity related to the progression of programmed cell death in tobacco plants. This may occur through the action of cystatin to inhibit cysteine proteases activated by MpNEP2 in plant tissues. Further studies are necessary to examine cystatin in the Theobroma cacao-M. perniciosa pathosystem.

Small-angle X-Ray analysis of macromolecular structure: the structure of protein NS2 (NEP) in solution

NASA Astrophysics Data System (ADS)

Shtykova, E. V.; Bogacheva, E. N.; Dadinova, L. A.; Jeffries, C. M.; Fedorova, N. V.; Golovko, A. O.; Baratova, L. A.; Batishchev, O. V.

2017-11-01

A complex structural analysis of nuclear export protein NS2 (NEP) of influenza virus A has been performed using bioinformatics predictive methods and small-angle X-ray scattering data. The behavior of NEP molecules in a solution (their aggregation, oligomerization, and dissociation, depending on the buffer composition) has been investigated. It was shown that stable associates are formed even in a conventional aqueous salt solution at physiological pH value. For the first time we have managed to get NEP dimers in solution, to analyze their structure, and to compare the models obtained using the method of the molecular tectonics with the spatial protein structure predicted by us using the bioinformatics methods. The results of the study provide a new insight into the structural features of nuclear export protein NS2 (NEP) of the influenza virus A, which is very important for viral infection development.

Study of a heat rejection system for the Nuclear Electric Propulsion (NEP) spacecraft

NASA Technical Reports Server (NTRS)

Ernest, D. M.

1982-01-01

Two different heat pipe radiator elements, one intended for use with the power conversion subsystem of the NASA funded nuclear electric propulsion (NEP) spacecraft, and one intended for use with the DOE funded space power advanced reactor (SPAR) system were tested and evaluated. The NEP stainless steel/sodium heat pipe was 4.42 meters long and had a 1 cm diameter. Thermal performance testing at 920 K showed a non-limited power level of 3560 watts, well in excess of the design power of 2600 watts. This test verified the applicability of screen arteries for use in long radiator heat pipes. The SPAR titanium/potassium heat pipe was 5.5 meters long and had a semicircular crossection with a 4 cm diameter. Thermal performance testing at 775 K showed a maximum power level of 1.86 kW, somewhat short of the desired 2.6 kW beginning of life design requirement. The reduced performance was shown to be the result of the inability of the evaporator wall wick (shot blasted evaporator wall) to handle the required liquid flow.

Effect of quercetin on plasma extravasation in rat CNS and dura mater by ACE and NEP inhibition.

PubMed

Cyrino, Luiz A R; Cardoso, Ronie C F; Hackl, Luciane P N; Nicolau, Mauro

2002-09-01

The effects of quercetin on substance P-induced plasma protein extravasation (PE) in the rat dura mater, cerebellum, olfactory bulb and cortex and also its modulation by endopeptidases, angiotensin-converting enzyme (ACE) and neutral endopeptidase (NEP) were studied. PE was assessed by photometric measurement of extravasated Evans blue. Substance P (SP) and NEP or ACE inhibitors increased the PE in dura mater. Pretreatment with captopril or phosphoramidon potentiated PE induced by SP in the dura mater and cerebellum, respectively. Quercetin increased the PE in the dura mater, cerebellum and cortex. Further results suggested that the PE induced by SP in the dura mater was enhanced by pretreatment with quercetin, similar to that observed with selective peptidase inhibitors. Quercetin-stimulated extravasation in all tissues was abolished by NK-1 receptor blockade. These results suggest that quercetin increases PE in the dura mater and CNS tissues by inhibiting NEP and/or ACE, showing that the effect induced in the dura mater, cerebellum and cortex occurs through endogenous SP accumulation. Copyright 2002 John Wiley & Sons, Ltd.

Preliminary Assessment of Thrust Augmentation of NEP Based Missions

NASA Technical Reports Server (NTRS)

Chew, Gilbert; Pelaccio, Dennis G.; Chiroux, Robert; Pervan, Sherry; Rauwolf, Gerald A.; White, Charles

2005-01-01

Science Applications International Corporation (SAIC), with support from NASA Marshall Space Flight Center, has conducted a preliminary study to compare options for augmenting the thrust of a conventional nuclear electric propulsion (NEP) system. These options include a novel nuclear propulsion system concept known as Hybrid Indirect Nuclear Propulsion (HINP) and conventional chemical propulsion. The utility and technical feasibility of the HINP concept are assessed, and features and potential of this new in-space propulsion system concept are identified. As part of the study, SAIC developed top-level design tools to model the size and performance of an HINP system, as well as for several chemical propulsion options, including liquid and gelled propellants. A mission trade study was performed to compare a representative HINP system with chemical propulsion options for thrust augmentation of NEP systems for a mission to Saturn's moon Titan. Details pertaining to the approach, features, initial demonstration results for HINP model development, and the mission trade study are presented. Key technology and design issues associated with the HINP concept and future work recommendations are also identified.

Impact of clinically tested NEP/ACE inhibitors on tumor uptake of [(111)In-DOTA]MG11-first estimates for clinical translation.

PubMed

Kaloudi, Aikaterini; Nock, Berthold A; Lymperis, Emmanouil; Valkema, Roelf; Krenning, Eric P; de Jong, Marion; Maina, Theodosia

2016-12-01

We have recently shown that treatment of mice with the neutral endopeptidase (NEP) inhibitor phosphoramidon (PA) improves the bioavailability and tumor uptake of biodegradable radiopeptides. For the truncated gastrin radiotracer [(111)In-DOTA]MG11 ([(DOTA)DGlu(10)]gastrin(10-17)), this method led to impressively high tumor-to-kidney ratios. Translation of this concept in the clinic requires the use of certified NEP inhibitors, such as thiorphan (TO) and its orally administered prodrug racecadotril (Race). Besides NEP, angiotensin-converting enzyme (ACE) has also been implicated in the catabolism of gastrin analogs. In the present study, we first compared the effects induced by NEP inhibition (using PA, TO, or Race) and/or by ACE inhibition (using lisinopril, Lis) on the biodistribution profile of [(111)In-DOTA]MG11 in mice. In addition, we compared the efficacy of PA and TO at different administered doses to enhance tumor uptake. [(111)In-DOTA]MG11 was coinjected with (a) vehicle, (b) PA (300 μg), (c) TO (150 μg), (d) Lis (100 μg), (e) PA (300 μg) plus Lis (100 μg), or (f) 30-40 min after intraperitoneal (ip) injection of Race (3 mg) in SCID mice bearing AR42J xenografts. In addition, [(111)In-DOTA]MG11 was coinjected with vehicle, or with progressively increasing amounts of PA (3, 30, or 300 μg) or TO (1.5, 15, and 150 μg) in SCID mice bearing twin A431-CCK2R(+/-) tumors. In all above cases, biodistribution was conducted at 4 h postinjection (pi). During NEP inhibition, the uptake of [(111)In-DOTA]MG11 in the AR42J tumors impressively increased from 1.8 ± 1.0 % ID/g (controls) to 15.3 ± 4.7 % ID/g (PA) and 12.3 ± 3.6 % ID/g (TO), while with Race tumor values reached 6.8 ± 2.8 % ID/g. Conversely, Lis had no effect on tumor uptake and no additive effect when coinjected with PA. During the dose dependence study in mice, PA turned out to be more efficacious in enhancing tumor uptake of [(111)In-DOTA]MG11 in the CCK2R

VizieR Online Data Catalog: AKARI NEP Survey sources at 18um (Pearson+, 2014)

NASA Astrophysics Data System (ADS)

Pearson, C. P.; Serjeant, S.; Oyabu, S.; Matsuhara, H.; Wada, T.; Goto, T.; Takagi, T.; Lee, H. M.; Im, M.; Ohyama, Y.; Kim, S. J.; Murata, K.

2015-04-01

The NEP-Deep survey at 18u in the IRC-L18W band is constructed from a total of 87 individual pointed observations taken between May 2006 to August 2007, using the IRC Astronomical Observing Template (AOT) designed for deep observations (IRC05), with approximately 2500 second exposures per IRC filter in all mid-infrared bands. The deep imaging IRC05 AOT has no explicit dithering built into the AOT operation, therefore dithering is achieved by layering separate pointed observations on at least three positions on a given piece of sky. The NEP-Wide survey consists of 446 pointed observations with .300 second exposures for each filter. The NEP-Wide survey uses the shallower IRC03 AOT optimized for large area multi-band mapping with the dithering included within the AOT. Note that for both surveys, although images are taken simultaneously in all three IRC channels, the target area of sky in the MIR-L channel is offset from the corresponding area of sky in the NIR/MIR-S channel by ~20arcmin. (2 data files).

Interactions between neutral endopeptidase (EC 3.4.24.11) and the substance P (NK1) receptor expressed in mammalian cells.

PubMed Central

Okamoto, A; Lovett, M; Payan, D G; Bunnett, N W

1994-01-01

Interactions between neutral endopeptidase-24.11 (NEP) and the substance P receptor (SPR; NK1) were investigated by examining substance P (SP) degradation, SP binding and SP-induced Ca2+ mobilization in epithelial cells transfected with cDNA encoding the rat SPR and rat NEP. Expression of NEP accelerated the degradation of SP by intact epithelial cells and by membrane preparations, and degradation was reduced by the NEP inhibitor thiorphan. In cells expressing SPR alone, specific 125I-SP binding after 20 min incubation at 37 degrees C was 92.2 +/- 3.1% of maximal binding and was unaffected by thiorphan. Coexpression of NEP in the same cells as the SPR markedly reduced SP binding to 13.9 +/- 0.5% of maximal, and binding was increased to 82.7 +/- 2.4% of maximal with thiorphan. Coexpression of NEP in the same cells as the SPR also reduced to undetectable the increase in intracellular Ca2+ in response to low concentrations of SP (0.3 and 0.5 nM), and significantly reduced the response to higher concentrations (1 and 3 nM). The Ca2+ response was restored to control values by inhibition of NEP with thiorphan. In contrast, SP binding and SP-induced Ca2+ mobilization were only slightly reduced when cells expressing SPR alone were mixed with a 3- to 24-fold excess of cells expressing NEP alone. Therefore, in this system, NEP markedly down-regulates SP binding and SP-induced Ca2+ mobilization only when coexpressed in the same cells as the SPR. Images Figure 1 Figure 2 PMID:7514869

Airway hyper-responsiveness to neurokinin A and bradykinin following Mycoplasma pneumoniae infection associated with reduced epithelial neutral endopeptidase.

PubMed

Tamaoki, J; Chiyotani, A; Tagaya, E; Araake, M; Nagai, A

1998-09-01

To determine whether mycoplasma infection produces airway hyper-responsiveness to tachykinins and bradykinin and, if so, to elucidate the role of neutral endopeptidase (NEP), isolated hamster tracheal segments were studied under isometric conditions in vitro. Nasal inoculation with Mycoplasma pneumoniae potentiated contractile responses to neurokinin A and bradykinin, causing a leftward shift of the dose-response curves to a lower concentration by 1 log unit for each agonist, whereas there was no response with acetylcholine. Pretreatment of tissues with the NEP inhibitor phosphoramidon augmented neurokinin A- and bradykinin-induced contractions in saline-treated control tissues, but did not further potentiate the responsiveness in M. pneumoniae-infected tissues. NEP activity in the tracheal epithelium, but not in epithelium-denuded tissues, was decreased in infected animals. These results suggest that M. pneumoniae infection causes airway bronchoconstrictor hyper-responsiveness to neurokinin A and bradykinin and that this effect may be associated with an inhibition of epithelial NEP activity.

Interactions between neutral endopeptidase (EC 3.4.24.11) and the substance P (NK1) receptor expressed in mammalian cells.

PubMed

Okamoto, A; Lovett, M; Payan, D G; Bunnett, N W

1994-05-01

Interactions between neutral endopeptidase-24.11 (NEP) and the substance P receptor (SPR; NK1) were investigated by examining substance P (SP) degradation, SP binding and SP-induced Ca2+ mobilization in epithelial cells transfected with cDNA encoding the rat SPR and rat NEP. Expression of NEP accelerated the degradation of SP by intact epithelial cells and by membrane preparations, and degradation was reduced by the NEP inhibitor thiorphan. In cells expressing SPR alone, specific 125I-SP binding after 20 min incubation at 37 degrees C was 92.2 +/- 3.1% of maximal binding and was unaffected by thiorphan. Coexpression of NEP in the same cells as the SPR markedly reduced SP binding to 13.9 +/- 0.5% of maximal, and binding was increased to 82.7 +/- 2.4% of maximal with thiorphan. Coexpression of NEP in the same cells as the SPR also reduced to undetectable the increase in intracellular Ca2+ in response to low concentrations of SP (0.3 and 0.5 nM), and significantly reduced the response to higher concentrations (1 and 3 nM). The Ca2+ response was restored to control values by inhibition of NEP with thiorphan. In contrast, SP binding and SP-induced Ca2+ mobilization were only slightly reduced when cells expressing SPR alone were mixed with a 3- to 24-fold excess of cells expressing NEP alone. Therefore, in this system, NEP markedly down-regulates SP binding and SP-induced Ca2+ mobilization only when coexpressed in the same cells as the SPR.

(99m)Tc-labeled gastrins of varying peptide chain length: Distinct impact of NEP/ACE-inhibition on stability and tumor uptake in mice.

PubMed

Kaloudi, Aikaterini; Nock, Berthold A; Lymperis, Emmanouil; Krenning, Eric P; de Jong, Marion; Maina, Theodosia

2016-06-01

In situ inhibition of neutral endopeptidase (NEP) has been recently shown to impressively increase the bioavailability and tumor uptake of biodegradable gastrin radioligands. Furthermore, angiotensin converting enzyme (ACE) has been previously shown to cleave gastrin analogs in vitro. In the present study, we have assessed the effects induced by single or dual NEP/ACE-inhibition on the pharmacokinetic profile of three (99m)Tc-labeled gastrins of varying peptide chain length: [(99m)Tc]SG6 ([(99m)Tc-N4-Gln(1)]gastrin(1-17)), [(99m)Tc]DG2 ([(99m)Tc-N4-Gly(4),DGlu(5)]gastrin(4-17)) and [(99m)Tc]DG4 ([(99m)Tc-N4-DGlu(10)]gastrin(10-17)). Mouse blood samples were collected 5min after injection of each of [(99m)Tc]SG6/DG2/DG4 together with: a) vehicle, b) the NEP-inhibitor phosphoramidon (PA), c) the ACE-inhibitor lisinopril (Lis), or d) PA plus Lis and were analyzed by RP-HPLC for radiometabolite detection. Biodistribution was studied in SCID mice bearing A431-CCK2R(+/-) xenografts at 4h postinjection (pi). [(99m)Tc]SG6 or [(99m)Tc]DG4 was coinjected with either vehicle or the above described NEP/ACE-inhibitor regimens; for [(99m)Tc]DG2 control and PA animal groups were only included. Treatment of mice with PA induced significant stabilization of (99m)Tc-radiotracers in peripheral blood, while treatment with Lis or Lis+PA affected the stability of des(Glu)5 [(99m)Tc]DG4 only. In line with these findings, PA coinjection led to notable amplification of tumor uptake of radiopeptides compared to controls (P<0.01). Only [(99m)Tc]DG4 profited by single Lis (2.06±0.39%ID/g vs 0.99±0.13%ID/g in controls) or combined Lis+PA coinjection (8.91±1.61%ID/g vs 4.89±1.33%ID/g in PA-group). Furthermore, kidney uptake remained favourably low and unaffected by PA and/or Lis coinjection only in the case of [(99m)Tc]DG4 (<1.9%ID/g) resulting in the most optimal tumor-to-kidney ratios. In situ NEP/ACE-inhibition diversely affected the in vivo profile of (99m)Tc-radioligands based on

Neutral endopeptidase inhibits neuropeptide-mediated transactivation of the insulin-like growth factor receptor-Akt cell survival pathway.

PubMed

Sumitomo, M; Milowsky, M I; Shen, R; Navarro, D; Dai, J; Asano, T; Hayakawa, M; Nanus, D M

2001-04-15

G-protein coupled receptor (GPCR) agonists such as neuropeptides activate the insulin-like growth factor-1 receptor (IGF-IR) or the serine-threonine protein kinase Akt, suggesting that neuropeptides-GPCR signaling can cross-communicate with IGF-IR-Akt signaling pathways. Neutral endopeptidase 24.11 (NEP) is a cell-surface peptidase that cleaves and inactivates the neuropeptides endothelin-1 (ET-1) and bombesin, which are implicated in progression to androgen-independent prostate cancer (PC). We investigated the mechanisms of NEP regulation of neuropeptide-mediated cell survival in PC cells, including whether neuropeptide substrates of NEP induce phosphorylations of IGF-IR and Akt in PC cells. Western analyses revealed ET-1 and bombesin treatment induced phosphorylation of IGF-IRbeta and Akt independent of IGF-I in TSU-Pr1, DU145, and PC-3 PC cells, which lack NEP expression, but not in NEP-expressing LNCaP cells. Recombinant NEP and induced NEP expression in TSU-Pr1 cells using a tetracycline-repressive expression system inhibited ET-1-mediated phosphorylation of IGF-IRbeta and Akt, and blocked the protective effects of ET-1 against apoptosis induced by serum starvation. Incubation of TSU-Pr1 cells with specific kinase inhibitors together with ET-1 or bombesin showed that IGF-IR activation is required for neuropeptide-induced Akt phosphorylation, and that neuropeptide-induced Akt activation is predominantly mediated by Src and phosphatidylinositol 3-kinase but not by mitogen-activated protein kinase or protein kinase C. These data show that the neuropeptides ET-1 and bombesin stimulate ligand-independent activation of the IGF-IR, which results in Akt activation, and that this cross-communication between GPCR and IGF-IR signaling is inhibited by NEP.

The New Ecological Paradigm Revisited: Anchoring the NEP Scale in Environmental Ethics

ERIC Educational Resources Information Center

Lundmark, Carina

2007-01-01

The New Environmental or Ecological Paradigm (NEP) is widely acknowledged as a reliable multiple-item scale to capture environmental attitudes or beliefs. It has been used in statistical analyses for almost 30 years, primarily by psychologists, but also by political scientists, sociologists and geographers. The scale's theoretical foundation is,…

NEP (Children@School): An Instrument for Measuring Environmental Attitudes in Middle Childhood

ERIC Educational Resources Information Center

Izadpanahi, Parisa; Tucker, Richard

2018-01-01

While there are many environmental education programs for children, few studies have used an appropriately developed scale for evaluating how such education might have on impact on children's environmental orientations. The research presented in this article adapted the NEP (New Ecological Paradigm) for Children scale to develop a new instrument…

Transcription Factor Arabidopsis Activating Factor1 Integrates Carbon Starvation Responses with Trehalose Metabolism1[OPEN

PubMed Central

Garapati, Prashanth; Feil, Regina; Lunn, John Edward; Van Dijck, Patrick; Balazadeh, Salma; Mueller-Roeber, Bernd

2015-01-01

Plants respond to low carbon supply by massive reprogramming of the transcriptome and metabolome. We show here that the carbon starvation-induced NAC (for NO APICAL MERISTEM/ARABIDOPSIS TRANSCRIPTION ACTIVATION FACTOR/CUP-SHAPED COTYLEDON) transcription factor Arabidopsis (Arabidopsis thaliana) Transcription Activation Factor1 (ATAF1) plays an important role in this physiological process. We identified TREHALASE1, the only trehalase-encoding gene in Arabidopsis, as a direct downstream target of ATAF1. Overexpression of ATAF1 activates TREHALASE1 expression and leads to reduced trehalose-6-phosphate levels and a sugar starvation metabolome. In accordance with changes in expression of starch biosynthesis- and breakdown-related genes, starch levels are generally reduced in ATAF1 overexpressors but elevated in ataf1 knockout plants. At the global transcriptome level, genes affected by ATAF1 are broadly associated with energy and carbon starvation responses. Furthermore, transcriptional responses triggered by ATAF1 largely overlap with expression patterns observed in plants starved for carbon or energy supply. Collectively, our data highlight the existence of a positively acting feedforward loop between ATAF1 expression, which is induced by carbon starvation, and the depletion of cellular carbon/energy pools that is triggered by the transcriptional regulation of downstream gene regulatory networks by ATAF1. PMID:26149570

Determination of 20Ne(p ,γ )21Na cross sections from Ep=500 -2000 keV

NASA Astrophysics Data System (ADS)

Lyons, S.; Görres, J.; deBoer, R. J.; Stech, E.; Chen, Y.; Gilardy, G.; Liu, Q.; Long, A. M.; Moran, M.; Robertson, D.; Seymour, C.; Vande Kolk, B.; Wiescher, M.; Best, A.

2018-06-01

Background: The reaction 20Ne(p ,γ )21Na influences the nucleosynthesis of Ne, Na, and Mg isotopes while contributing to hydrogen burning in several stellar sites, such as red giants, asymptotic giant branch (AGB) stars, massive stars, and oxygen-neon (ONe) novae. In the relevant temperature range for these environments (T = 0.05-0.5 GK), the main contributions to this reaction rate are from the direct capture process as well as the high-energy tail of a subthreshold resonance in the ground-state transition at Ex = 2425 keV in the 21Na compound nucleus. Purpose: The previous measurement of this reaction reports cross sections with large uncertainties for the ground-state transition. At higher energies, where the subthreshold resonance makes a smaller contribution to the total cross section, only upper limits are provided. This work aims to reduce the uncertainty in the cross section where direct capture dominates, as well as provide cross-section data in previously unmeasured regions. Method: The 20Ne(p ,γ )21Na reaction was measured over a wide proton energy range (Ep = 0.5-2.0 MeV) at θlab = 90∘. Transitions to the ground state and to the 332 and 2425 keV excited states were observed. The primary transitions to these three bound states were utilized in an R -matrix analysis to determine the contributions of the direct capture and the subthreshold resonance to the total cross section. Results: The cross sections of the present measurements have been found to be in good agreement with the previous data at low energy. Significantly improved cross-section measurements have been obtained over the Ep = 1300-1900 keV region. The narrow resonance at Ec.m. = 1113 keV (Ex = 3544.3 keV) has also been remeasured and its strength has been found to be in good agreement with previous measurements. Conclusions: An extrapolation of the S factor of 20Ne(p ,γ )21Na has been made to low energies using the R -matrix fit. The reaction rate from the subthreshold resonance was

Toluene diisocyanate increases airway responsiveness to substance P and decreases airway neutral endopeptidase.

PubMed

Sheppard, D; Thompson, J E; Scypinski, L; Dusser, D; Nadel, J A; Borson, D B

1988-04-01

Substance P and related tachykinins contribute to the airway hyperresponsiveness caused by toluene diisocyanate (TDI) in guinea pigs. Neutral endopeptidase (NEP) is an important modulator of substance P-induced responses. To test the hypothesis that exposure to TDI would increase responsiveness to substance P by inhibiting activity of this enzyme, we determined the dose of substance P required to increase pulmonary resistance by 200% above baseline (PD200) before and after administration of the pharmacologic inhibitor phosphoramidon in guinea pigs studied 1 h after a 1-h exposure to air or 3 ppm TDI. TDI exposure increased responsiveness to substance P significantly. However, phosphoramidon caused a significantly greater leftward shift of the substance P dose-response curve in air-exposed animals than it did in TDI-exposed animals, so that after phosphoramidon, mean values of PD200 in animals exposed to air or TDI did not differ. Tracheal NEP activity was significantly less after exposure to TDI than after exposure to air, whereas activity in the esophagus was the same in both groups. These results suggest that TDI exposure increases the bronchoconstrictor responsiveness of guinea pigs to substance P, in large part through inhibition of airway NEP.

Toluene diisocyanate increases airway responsiveness to substance P and decreases airway neutral endopeptidase.

PubMed Central

Sheppard, D; Thompson, J E; Scypinski, L; Dusser, D; Nadel, J A; Borson, D B

1988-01-01

Substance P and related tachykinins contribute to the airway hyperresponsiveness caused by toluene diisocyanate (TDI) in guinea pigs. Neutral endopeptidase (NEP) is an important modulator of substance P-induced responses. To test the hypothesis that exposure to TDI would increase responsiveness to substance P by inhibiting activity of this enzyme, we determined the dose of substance P required to increase pulmonary resistance by 200% above baseline (PD200) before and after administration of the pharmacologic inhibitor phosphoramidon in guinea pigs studied 1 h after a 1-h exposure to air or 3 ppm TDI. TDI exposure increased responsiveness to substance P significantly. However, phosphoramidon caused a significantly greater leftward shift of the substance P dose-response curve in air-exposed animals than it did in TDI-exposed animals, so that after phosphoramidon, mean values of PD200 in animals exposed to air or TDI did not differ. Tracheal NEP activity was significantly less after exposure to TDI than after exposure to air, whereas activity in the esophagus was the same in both groups. These results suggest that TDI exposure increases the bronchoconstrictor responsiveness of guinea pigs to substance P, in large part through inhibition of airway NEP. PMID:2450892

Aquatic metabolism response to the hydrologic alteration in the Yellow River estuary, China

NASA Astrophysics Data System (ADS)

Shen, Xiaomei; Sun, Tao; Liu, Fangfang; Xu, Jing; Pang, Aiping

2015-06-01

Successful artificial hydrologic regulation and environmental flow assessments for the ecosystem protection require an accurate understanding of the linkages between flow events and biotic responses. To explore an ecosystem's functional responses to hydrologic alterations, we analysed spatial and temporal variations in aquatic metabolism and the main factors influenced by artificial hydrologic alterations based on the data collected from 2009 to 2012 in the Yellow River estuary, China. Gross primary production (GPP) ranged from 0.002 to 8.488 mg O2 L-1 d-1. Ecosystem respiration (ER) ranged from 0.382 to 8.968 mg O2 L-1 d-1. Net ecosystem production (NEP) ranged from -5.792 to 7.293 mg O2 L-1 d-1 and the mean of NEP was -0.506 mg O2 L-1 d-1, which means that the trophic status of entire estuary was near to balance. The results showed that seasonal variations in the aquatic metabolism are influenced by the hydrologic alteration in the estuary. High water temperature and solar radiation in summer are associated with low turbidity and consequently high rates of GPP and ER, making the estuary net autotrophic in summer, and that also occurred after water-sediment regulation in August. Turbidity and water temperature were identified as two particularly important factors that influenced the variation in the metabolic balance. As a result, metabolism rate did not decrease but increased after the regulation. ER increased significantly in summer and autumn and reached a maximum after the water-sediment regulation in September. GPP and NEP reached a maximum value after the water-sediment regulation in August, and then decreased in autumn. Estuarine ecosystem shifted from net heterotrophy in spring to net autotrophy in summer, and then to net heterotrophy in autumn. Our study indicated that estuarine metabolism may recover to a high level faster in summer than that in other seasons after the short-term water-sediment regulation due to higher water temperature and nutrients.

Administration of SIN-1 induces guinea pig airway hyperresponsiveness through inactivation of airway neutral endopeptidase.

PubMed

Kanazawa, H; Hirata, K; Yoshikawa, J

1999-12-01

Peroxynitrite plays an important role in the pathogenesis of airway inflammation. We have already found that peroxynitrite may contribute to decreased beta(2)-adrenoceptor responses in airway smooth muscle. However, it is not known whether peroxynitrite can alter neutral endopeptidase (EC 3.4.24.11; NEP) activity in the airways. This study was designed to determine whether peroxynitrite induces airway hyperresponsiveness to substance P (SP) and endothelin-1 (ET-1) through the inactivation of airway NEP. We examined whether the administration of S-morpholinosydnonimine (SIN-1), a compound that releases peroxynitrite, increased bronchoconstrictor responses to SP and ET-1 in anesthetized guinea pigs. In addition, we assayed NEP activity in the airways of SIN-1-exposed guinea pigs. Though SIN-1 (10(-7) M) alone had no effect on pulmonary resistance, pretreatment with SIN-1 significantly enhanced SP- and ET-1-induced bronchoconstriction. Pretreatment with phosphoramidon, an NEP inhibitor, also enhanced SP- and ET-1-induced bronchoconstriction. However, simultaneous administration of phosphoramidon and SIN-1 had no additive effect on SP- and ET-1-induced bronchoconstriction. Peroxynitrite formation by SIN-1 was completely inhibited by N-acetylcysteine (NAC) and glutathione (GSH) in vitro, and pretreatment with NAC and GSH significantly reversed the potentiation by SIN-1 of SP-induced bronchoconstriction. In addition, the NEP activity of the trachea after SIN-1 exposure was significantly reduced compared to the level in control guinea pigs (solvent for SIN-1: 30.0+/-4.2 fmol.min(-1).mg tissue(-1); 10(-7) M SIN-1; 15.5+/-4.5 fmol.min(-1).mg tissue(-1), p<0.05). These findings suggest that peroxynitrite induces airway hyperresponsiveness to SP and ET-1 through the inactivation of airway NEP, and that peroxynitrite is an important mediator of the alterations in airway functions.

NEPRILYSIN REGULATES PULMONARY ARTERY SMOOTH MUSCLE CELL PHENOTYPE THROUGH A PDGF RECEPTOR DEPENDENT MECHANISM

PubMed Central

Karoor, Vijaya; Oka, Masahiko; Walchak, Sandra J.; Hersh, Louis B.; Miller, York E.; Dempsey, Edward C.

2013-01-01

Reduced neprilysin (NEP), a cell surface metallopeptidase, which cleaves and inactivates pro-inflammatory and vasoactive peptides, predisposes the lung vasculature to exaggerated remodeling in response to hypoxia. We hypothesize that loss of NEP in pulmonary artery smooth muscle cells (PASMCs) results in increased migration and proliferation. PASMCs isolated from NEP−/− mice exhibited enhanced migration and proliferation in response to serum and PDGF, which was attenuated by NEP replacement. Inhibition of NEP by overexpression of a peptidase dead mutant or knockdown by siRNA in NEP+/+ cells increased migration and proliferation. Loss of NEP led to an increase in Src kinase activity and phosphorylation of PTEN resulting in activation of the PDGF receptor (PDGFR). Knockdown of Src kinase with siRNA or inhibition with PP2 a src kinase inhibitor decreased PDGFRY751 phosphorylation and attenuated migration and proliferation in NEP−/− SMCs. NEP substrates, endothelin-1(ET-1) or fibroblast growth factor-2 (FGF2), increased activation of Src and PDGFR in NEP+/+ cells, which was decreased by an ETAR antagonist, neutralizing antibody to FGF2 and Src inhibitor. Similar to the observations in PASMCs levels of p-PDGFR, p-Src and p-PTEN were elevated in NEP−/− lungs. ETAR antagonist also attenuated the enhanced responses in NEP−/−PASMCs and lungs. Taken together our results suggest a novel mechanism for regulation of PDGFR signaling by NEP substrates involving Src and PTEN. Strategies that increase lung NEP activity/expression or target key downstream effectors, like Src, PTEN or PDGFR, may be of therapeutic benefit in pulmonary vascular disease. PMID:23381789

Conceptual definition of a 50-100 kWe NEP system for planetary science missions

NASA Technical Reports Server (NTRS)

Friedlander, Alan

1993-01-01

The Phase 1 objective of this project is to assess the applicability of a common Nuclear Electric Propulsion (NEP) flight system of the 50-100 kWe power class to meet the advanced transportation requirements of a suite of planetary science (robotic) missions, accounting for differences in mission-specific payloads and delivery requirements. The candidate missions are as follows: (1) Comet Nucleus Sample Return; (2) Multiple Mainbelt Asteroid Rendezvous; (3) Jupiter Grand Tour (Galilean satellites and magnetosphere); (4) Uranus Orbiter/Probe (atmospheric entry and landers); (5) Neptune Orbiter/Probe (atmospheric entry and landers); and (6) Pluto-Charon Orbiter/Lander. The discussion is presented in vugraph form.

Role of substance P in neutral endopeptidase modulation of hypoxic response of the carotid body.

PubMed

Kumar, G K; Yu, R K; Overholt, J L; Prabhakar, N R

2000-01-01

Carotid body expresses neutral endopeptidase (NEP)-like enzyme activity and phosphoramidon, an inhibitor of NEP augments sensory response of the carotid body to hypoxia (Kumar et al., 1990). NEP hydrolyzes substance P (SP) and methionine enkephalin (Met-ENK) in the nervous system. In the present study, we determined whether NEP hydrolyzes Met-ENK and SP in the carotid body and whether these peptides contribute to the phosphoramidon-induced potentiation of the sensory response to hypoxia. Experiments were performed on carotid bodies excised from anaesthetized adult cats. HPLC analysis showed that both SP and Met-ENK were hydrolyzed by the carotid body. Phosphoramidon (400 microM) markedly inhibited SP (approximately 90%) but had only marginal effect on Met-ENK hydrolysis (approximately 15%). Sensory responses of the carotid body in vitro to hypoxia (pO2, 68 +/- 6 mmHg) and SP (10 nmoles) were potentiated by phosphoramidon by approximately 80% and approximately 275% respectively (p < 0.01). SP-receptor antagonist abolished phosphoramidon-induced potentiation of the sensory response to hypoxia as well as to SP. These results demonstrate that SP is a preferred substrate for NEP in the carotid body and SP plays a major role in the potentiation of the hypoxic response of the carotid body by phosphoramidon.

Neutral endopeptidase regulates neurogenic inflammatory responses induced by stimulation of human oral keratinocytes with bacterial lipopolysaccharide and nicotine.

PubMed

Nakata, Motoki; Awano, Shuji; Kinoshita, Naomasa; Yoshida, Akihiro; Ansai, Toshihiro

2013-10-01

Neutral endopeptidase (NEP) is present on various epithelial cells and inactivates numerous physiologically active peptides. Neutral endopeptidase may regulate proinflammatory signals in oral mucosal epithelium. However, the function of NEP in oral mucosal epithelium is unknown. The present study investigated the action of NEP upon proinflammatory signals on human oral keratinocytes and the influence of endothelin-converting enzyme (ECE)-1, an enzyme similar to NEP, on the functions of NEP. Oral keratinocytes were cultured in medium containing inflammatory inducers [lipopolysaccharide (LPS) and nicotine], NEP inhibitors, and ECE-1/NEP inhibitors, either alone or in combination. The concentrations of substance P (SP) and interleukin-1β (IL-1β) were measured in the supernatant. Additionally, the concentrations of SP and IL-1β were measured in the supernatant of cells incubated with LPS or nicotine after transfection with NEP small interfering RNA (siRNA). The concentrations of SP and IL-1β were significantly increased in cells incubated with NEP inhibitors and, to a lesser extent, in cells incubated with ECE-1/NEP inhibitors, compared with controls (cells incubated with LPS or nicotine alone). The concentrations of SP and IL-1β in cells transfected with NEP siRNA were significantly augmented compared with controls. In conclusion, the present study demonstrated that NEP down-regulated the levels of SP and IL-1β produced from human oral keratinocytes, although ECE-1 may be partly related to the down-regulation. © 2013 Eur J Oral Sci.

Three New Low-Energy Resonances in the 22Ne(p, γ )23Na Reaction

NASA Astrophysics Data System (ADS)

Cavanna, Francesca; Depalo, Rosanna

The neon-sodium (NeNa) cycle drives the synthesis of the elements between 20Ne and 27Al, through a series of proton capture reactions that start from 20Ne, to end with sodium synthesis. This cycle is active in red giant stars (RGB), asymptotic giant branch stars (AGB), in novae as well as in type Ia supernovae. In order to reproduce the observed elemental abundances, the cross sections of the reactions involved in the nucleosynthesis process should be accurately known. The 22Ne(p, γ )23Na reaction rate was very uncertain because of a large number of unobserved resonances lying in the Gamow window. For proton energies below 400 keV, in the literature there were only upper limits for the resonance strengths. A new direct study of the 22Ne(p, γ )23Na reaction has been performed at the Laboratory for Underground Nuclear Astrophysics (LUNA) in Gran Sasso using a windowless gas target and two high-purity germanium detectors. Several resonances have been observed for the first time in a direct experiment.

SuperSpec, The On-Chip Spectrometer: Improved NEP and Antenna Performance

NASA Astrophysics Data System (ADS)

Wheeler, Jordan; Hailey-Dunsheath, S.; Shirokoff, E.; Barry, P. S.; Bradford, C. M.; Chapman, S.; Che, G.; Doyle, S.; Glenn, J.; Gordon, S.; Hollister, M.; Kovács, A.; LeDuc, H. G.; Mauskopf, P.; McGeehan, R.; McKenney, C.; Reck, T.; Redford, J.; Ross, C.; Shiu, C.; Tucker, C.; Turner, J.; Walker, S.; Zmuidzinas, J.

2018-05-01

SuperSpec is a new technology for mm and sub-mm spectroscopy. It is an on-chip spectrometer being developed for multi-object, moderate-resolution (R˜ 300 ), large bandwidth survey spectroscopy of high-redshift galaxies for the 1 mm atmospheric window. This band accesses the CO ladder in the redshift range of z = 0-4 and the [CII] 158 μm line from redshift z = 5-9. SuperSpec employs a novel architecture in which detectors are coupled to a series of resonant filters along a single microwave feedline instead of using dispersive optics. This construction allows for the creation of a full spectrometer occupying only ˜ 10 cm^2 of silicon, a reduction in size of several orders of magnitude when compared to standard grating spectrometers. This small profile enables the production of future multi-beam spectroscopic instruments envisioned for the millimeter band to measure the redshifts of dusty galaxies efficiently. The SuperSpec collaboration is currently pushing toward the deployment of a SuperSpec demonstration instrument in fall of 2018. The progress with the latest SuperSpec prototype devices is presented; reporting increased responsivity via a reduced inductor volume (2.6 μm^3 ) and the incorporation of a new broadband antenna. A detector NEP of 3-4 × 10^{-18} W/Hz^{0.5} is obtained, sufficient for background-limited observation on mountaintop sites. In addition, beam maps and efficiency measurements of a new wide-band dual bow-tie slot antenna are shown.

Suppressor of gamma response 1 (SOG1) encodes a putative transcription factor governing multiple responses to DNA damage

PubMed Central

Yoshiyama, Kaoru; Conklin, Phillip A.; Huefner, Neil D.; Britt, Anne B.

2009-01-01

The Arabidopsis sog1-1 (suppressor of gamma response) mutant was originally isolated as a second-site suppressor of the radiosensitive phenotype of seeds defective in the repair endonuclease XPF. Here, we report that SOG1 encodes a putative transcription factor. This gene is a member of the NAC domain [petunia NAM (no apical meristem) and Arabidopsis ATAF1, 2 and CUC2] family (a family of proteins unique to land plants). Hundreds of genes are normally up-regulated in Arabidopsis within an hour of treatment with ionizing radiation; the induction of these genes requires the damage response protein kinase ATM, but not the related kinase ATR. Here, we find that SOG1 is also required for this transcriptional up-regulation. In contrast, the SOG1-dependent checkpoint response observed in xpf mutant seeds requires ATR, but does not require ATM. Thus, phenotype of the sog1-1 mutant mimics aspects of the phenotypes of both atr and atm mutants in Arabidopsis, suggesting that SOG1 participates in pathways governed by both of these sensor kinases. We propose that, in plants, signals related to genomic stress are processed through a single, central transcription factor, SOG1. PMID:19549833

Net Ecosystem Production (NEP) of the Great Plains, United States

USGS Publications Warehouse

Howard, Daniel; Gilmanov, Tagir; Gu, Yingxin; Wylie, Bruce; Zhang, Li

2012-01-01

Flux tower networks, such as AmeriFlux and FLUXNET, consist of a growing number of eddy covariance flux tower sites that provide a synoptic record of the exchange of carbon, water, and energy between the ecosystem and atmosphere at various temporal frequencies. These towers also detect and measure certain site characteristics, such as wind, temperature, precipitation, humidity, atmospheric pressure, soil features, and phenological progressions. Efforts are continuous to combine flux tower network data with remote sensing data to upscale the conditions observed at specific sites to a regional and, ultimately, worldwide scale. Data-driven regression tree models have the ability to incorporate flux tower records and remote sensing data to quantify exchanges of carbon with the atmosphere (Wylie and others, 2007; Xiao and others, 2010; Zhang and others, 2010; Zhang and others, 2011). Previous study results demonstrated the dramatic effect weather has on NEP and revealed specific ecoregions and times acting as carbon sinks or sources. As of 2012, more than 100 site-years of flux tower measurements, represented by more than 50 individual cropland or grassland sites throughout the Great Plains and surrounding area, have been acquired, quality controlled, and partitioned into gross photosynthesis (Pg) and ecosystem Re using detailed light-response, soil temperature, and vapor pressure deficit (VPD) based analysis.

Negative feedback on the effects of stem cell factor on hematopoiesis is partly mediated through neutral endopeptidase activity on substance P: a combined functional and proteomic study.

PubMed

Joshi, D D; Dang, A; Yadav, P; Qian, J; Bandari, P S; Chen, K; Donnelly, R; Castro, T; Gascon, P; Haider, A; Rameshwar, P

2001-11-01

Hematopoietic regulation is a complex but dynamic process regulated by intercellular and intracellular interactions within the bone marrow (BM) microenvironment. Through neurokinin-1 (NK-1) and NK-2 receptors, peptides (eg, substance P [SP]) encoded by the preprotachykinin-I gene mediate distinct hematopoietic effects. Cytokines, associated with hematopoietic stimulation, and SP regulate the expression of each other in BM mesenchymal and immune cells. Neutral endopeptidase (NEP) uses SP as a substrate to produce SP(1-4), which inhibits the proliferation of matured myeloid progenitor. This study determines whether the degradation of SP to SP(1-4) by endogenous NEP in BM stroma could be a feedback on hematopoietic stimulation by stem cell factor (SCF). SP(1-4) induced the production of transforming growth factor (TGF)-beta and tumor necrosis factor-alpha in BM stroma. TGF-beta production accounted for part of the inhibitory effects by SP(1-4) on the proliferation of early (granulocyte-macrophage colony-forming units) and late (long-term culture-initiating cells) hematopoietic progenitors. Enzyme-linked immunosorbent assays and/or protein-chip arrays indicated a timeline change of SP to SP(1-4) in BM stroma stimulated with SCF, which correlated with increase in NEP messenger RNA. Since SP and its fragment, SP(1-4), interact with the same receptor to mediate opposing hematopoietic effects, 2 interactive studies were done to understand the dual responses of NK-1: (1) a 3-dimensional molecular model of NK-1 and SP and (2) screening of a random dodecapeptide library for SP(1-4) interacting sites. The effects of SP(1-4) on hematopoietic progenitors and the timeline change of SP to SP(1-4), together with the 3-dimensional model, provide a partial explanation for the feedback on the stimulatory effects of SCF and SP on hematopoiesis.

Neutral endopeptidase terminates substance P-induced inflammation in allergic contact dermatitis.

PubMed

Scholzen, T E; Steinhoff, M; Bonaccorsi, P; Klein, R; Amadesi, S; Geppetti, P; Lu, B; Gerard, N P; Olerud, J E; Luger, T A; Bunnett, N W; Grady, E F; Armstrong, C A; Ansel, J C

2001-01-15

Sensory nerve-derived neuropeptides such as substance P demonstrate a number of proinflammatory bioactivities, but less is known about their role in inflammatory skin disease. The cell surface metalloprotease neutral endopeptidase (NEP) is the principal proteolytic substance P-degrading enzyme. This study tests the hypothesis that the absence of NEP results in dysregulated inflammatory skin responses. The effector phase of allergic contact dermatitis (ACD) responses was examined in NEP(-/-) knockout and NEP(+/+) wild-type mice and compared with the irritant contact dermatitis response in these animals. NEP was found to be normally immunolocalized in epidermal keratinocytes and dermal blood vessels. The ACD ear swelling response was 2.5-fold higher in animals lacking NEP and was accompanied by a significant increase in plasma extravasation and infiltration of inflammatory leukocytes. The augmented ACD response in NEP(-/-) animals was abrogated by either administration of a neurokinin receptor 1 antagonist or by repeated pretreatment with topical capsaicin. Similar to NEP(-/-) mice, the acute inhibition of NEP in NEP(+/+) animals resulted in an augmented ACD response. In contrast to the ACD responses, little differences were observed in the irritant contact dermatitis response of NEP(-/-) compared with NEP(+/+) animals after epicutaneous application of the skin irritants croton oil or SDS. Thus, these results indicate that NEP and cutaneous neuropeptides have a significant role in the pathogenesis of ACD.

Application of Molten Salt Reactor Technology to MMW In-Space NEP and Surface Power Missions

NASA Technical Reports Server (NTRS)

Patton, Bruce; Sorensen, Kirk; Rodgers, Stephen (Technical Monitor)

2002-01-01

Anticipated manned nuclear electric propulsion (NEP) and planetary surface power missions will require multimegawatt nuclear reactors that are lightweight, operationally robust, and scalable in power for widely varying scientific mission objectives. Molten salt reactor technology meets all of these requirements and offers an interesting alternative to traditional multimegawatt gas-cooled and liquid metal concepts.

Nep-Akari Evolution with Redshift of Dust Attenuation in 8 ㎛ Selected Galaxies

NASA Astrophysics Data System (ADS)

Buat, V.; Oi, N.; Burgarella, D.; Malek, K.; Matsuhara, H.; Murata, K.; Serjeant, S.; Takeuchi, T. T.; Malkan, M.; Pearson, C.; Wada, T.

2017-03-01

We built a 8um selected sample of galaxies in the NEP-AKARI field by defining 4 redshift bins with the four AKARI bands at 11, 15, 18 and 24 microns (0.151.34, 1.341.7 and 1.7

Monitoring early tumor response to drug therapy with diffuse optical tomography

NASA Astrophysics Data System (ADS)

Flexman, Molly L.; Vlachos, Fotios; Kim, Hyun Keol; Sirsi, Shashank R.; Huang, Jianzhong; Hernandez, Sonia L.; Johung, Tessa B.; Gander, Jeffrey W.; Reichstein, Ari R.; Lampl, Brooke S.; Wang, Antai; Borden, Mark A.; Yamashiro, Darrell J.; Kandel, Jessica J.; Hielscher, Andreas H.

2012-01-01

Although anti-angiogenic agents have shown promise as cancer therapeutics, their efficacy varies between tumor types and individual patients. Providing patient-specific metrics through rapid noninvasive imaging can help tailor drug treatment by optimizing dosages, timing of drug cycles, and duration of therapy--thereby reducing toxicity and cost and improving patient outcome. Diffuse optical tomography (DOT) is a noninvasive three-dimensional imaging modality that has been shown to capture physiologic changes in tumors through visualization of oxygenated, deoxygenated, and total hemoglobin concentrations, using non-ionizing radiation with near-infrared light. We employed a small animal model to ascertain if tumor response to bevacizumab (BV), an anti-angiogenic agent that targets vascular endothelial growth factor (VEGF), could be detected at early time points using DOT. We detected a significant decrease in total hemoglobin levels as soon as one day after BV treatment in responder xenograft tumors (SK-NEP-1), but not in SK-NEP-1 control tumors or in non-responder control or BV-treated NGP tumors. These results are confirmed by magnetic resonance imaging T2 relaxometry and lectin perfusion studies. Noninvasive DOT imaging may allow for earlier and more effective control of anti-angiogenic therapy.

Heat shock factor 1 suppresses the HIV-induced inflammatory response by inhibiting nuclear factor-κB.

PubMed

Pan, Xiaoyan; Lin, Jian; Zeng, Xiaoyun; Li, Wenjuan; Wu, Wenjiao; Lu, Wan Zhen; Liu, Jing; Liu, Shuwen

2018-05-01

The persistent inflammation aggravated by a disordered immune response is considered to be the major cause of CD4 + T cell depletion in lymphoid tissue, which impels the progression of AIDS. Here, we report that heat shock factor 1 (HSF1) works as an innate repressor of HIV-induced inflammation. The activation of HSF1 was found to accompany inflammation during HIV infection. Further research uncovered that HSF1 activation inhibited HIV-induced inflammation. In addition, HSF1 overexpression suppressed the inflammatory response induced by HIV, while HSF1 deficiency exacerbated that inflammation. Mechanistically, HSF1 was found to compete with nuclear factor-κB (NF-κB) in the nucleus. Generally, our report highlights that HSF1 is an important host factor in regulating HIV-induced inflammation and may work as a potential target for curing AIDS. Copyright © 2018 Elsevier Inc. All rights reserved.

Effects of neutral endopeptidase (neprilysin) inhibition on the response to other vasoactive peptides in small human resistance arteries: studies with thiorphan and omapatrilat.

PubMed

Dalzell, Jonathan R; Seed, Alison; Berry, Colin; Whelan, Carol J; Petrie, Mark C; Padmanabhan, Neal; Clarke, Amanda; Biggerstaff, Fiona; Hillier, Christopher; McMurray, John J V

2014-02-01

New compounds with neprilysin or neutral endopeptidase (NEP) inhibiting activity are under clinical investigation in heart failure and hypertension. We investigated the effect of NEP inhibition on the functional vasomotor responses to a range of vasoactive peptides in human blood vessels. Small human resistance arteries from patients with coronary artery disease and preserved left ventricular systolic function were studied. Thiorphan (a NEP inhibitor) was compared with captopril (an ACE inhibitor) and omapatrilat (a dual NEP-ACE inhibitor) with regard to their effects on the response of human arteries to key vasoactive peptides. As expected, both captopril and omapatrilat (but not thiorphan) inhibited the vasoconstrictor effect of angiotensin I (maximal response [SEM]: 27 ± 8% vehicle, 6 ± 2% captopril, 39 ± 10% thiorphan, 8 ± 7% omapatrilat, P < 0.05). Thiorphan, captopril, and omapatrilat all enhanced the vasodilator response to bradykinin (all P < 0.01). Omapatrilat markedly augmented the vasodilator action of adrenomedullin (P < 0.05), whilst thiorphan and captopril did not. None of the three inhibitors studied affected the vasodilator action of c-type natriuretic peptide, calcitonin gene-related peptide, vasoactive intestinal polypeptide or substance P. NEP inhibition with thiorphan modestly augmented the vasodilator action of bradykinin, but did not potentiate the response to adrenomedullin; dual ACE and NEP inhibition with omapatrilat, as expected, markedly augmented the response to bradykinin and also potentiated the effect of adrenomedullin. Thiorphan weakly enhanced the vasoconstrictor response to angiotensin I. Neither omapatrilat nor thiorphan had any effect on the action of a range of other vasoactive peptides including CNP. © 2013 John Wiley & Sons Ltd.

Nogo-receptor 1 antagonization in combination with neurotrophin-4/5 is not superior to single factor treatment in promoting survival and morphological complexity of cultured dopaminergic neurons.

PubMed

Seiler, Stefanie; Di Santo, Stefano; Sahli, Sebastian; Andereggen, Lukas; Widmer, Hans Rudolf

2017-08-01

Cell transplantation using ventral mesencephalic tissue is an experimental approach to treat Parkinson's disease. This approach is limited by poor survival of the transplants and the high number of dopaminergic neurons needed for grafting. Increasing the yield of dopaminergic neurons in donor tissue is of great importance. We have previously shown that antagonization of the Nogo-receptor 1 by NEP1-40 promoted survival of cultured dopaminergic neurons and exposure to neurotrophin-4/5 increased dopaminergic cell densities in organotypic midbrain cultures. We investigated whether a combination of both treatments offers a novel tool to further improve dopaminergic neuron survival. Rat embryonic ventral mesencephalic neurons grown as organotypic free-floating roller tube or primary dissociated cultures were exposed to neurotrophin-4/5 and NEP1-40. The combined and single factor treatment resulted in significantly higher numbers of tyrosine hydroxylase positive neurons compared to controls. Significantly stronger tyrosine hydroxylase signal intensity was detected by Western blotting in the combination-treated cultures compared to controls but not compared to single factor treatments. Neurotrophin-4/5 and the combined treatment showed significantly higher signals for the neuronal marker microtubule-associated protein 2 in Western blots compared to control while no effects were observed for the astroglial marker glial fibrillary acidic protein between groups, suggesting that neurotrophin-4/5 targets mainly neuronal cells. Finally, NEP1-40 and the combined treatment significantly augmented tyrosine hydroxylase positive neurite length. Summarizing, our findings substantiate that antagonization of the Nogo-receptor 1 promotes dopaminergic neurons but does not further increase the yield of dopaminergic neurons and their morphological complexity when combined with neurotrophin-4/5 hinting to the idea that these treatments might exert their effects by activating common

Prevalence of tidal expiratory flow limitation in preschool children with and without respiratory symptoms: application of the negative expiratory pressure (NEP) method.

PubMed

JIRICKOVA, A; SULC, J; POHUNEK, P; KITTNAR, O; DOHNALOVA, A; KOFRANEK, J

2009-01-01

Negative expiratory pressure (NEP) applied at the mouth during tidal expiration provides a non-invasive method for detecting expiratory flow limitation. Forty-two children were studied, i.e. 25 children with different respiratory symptoms (R) and 17 without any respiratory symptoms (NR). Children were examined without any sedation. A preset NEP of -5 cm H(2)O was applied; its duration did not exceed duration of tidal expiration. A significance of FL was judged by determining of a flow-limited range (in % of tidal volume). FL was found in 48 % children of R group. No patient of the NR group elicited FL (P<0.001 R vs. NR). The frequency of upper airway collapses was higher in R group (12 children) than in NR group (5 children). In conclusion, a high frequency of tidal FL in the R group was found, while it was not present in NR group. A relatively high frequency of expiratory upper airway collapses was found in both groups, but it did not differ significantly. NEP method represents a reasonable approach for tidal flow limitation testing in non-sedated preschool children.

Fundamental research on spiking, recovery and understanding seed coat nep counts in AFIS analysis of pre-opened cotton

USDA-ARS?s Scientific Manuscript database

Understanding seed coat fragment (SCF) spiking results in Advanced Fiber Information Systems (AFIS) analysis of seed coat neps (SCN) in ginned cottons was confounded by side processes in the system such as particle crushing that results in inflated recoveries. A high degree of machine (AFIS)-fiber ...

Tracheal smooth muscle responses to substance P and neurokinin A in the piglet.

PubMed

Haxhiu-Poskurica, B; Haxhiu, M A; Kumar, G K; Miller, M J; Martin, R J

1992-03-01

The tachykinins substance P (SP) and neurokinin A (NKA) have been shown to induce airway smooth muscle contraction in mature animals, and the enzyme neutral endopeptidase (NEP) modulates this effect. We evaluated maturation of SP- and NKA-induced tracheal smooth muscle contraction and modulation of their effects by NEP in anesthetized, paralyzed, and artificially ventilated piglets less than 4 days, 2-3 wk, and 10 wk of age. Tracheal smooth muscle tension was measured in vivo from an open tracheal segment by use of a force transducer. Intravenous SP caused a dose-dependent increase in tracheal tension in all three age groups; however, the response in less than 4-day-old piglets was significantly weaker than in 2- to 3- and 10-wk-old piglets. NKA caused a dose-dependent increase in tracheal tension only in 2- to 3- and 10-wk-old piglets. The response of tracheal tension to NKA was weaker than the response to SP in all age groups. Atropine (2 mg/kg) significantly diminished the responses of tracheal tension to SP and NKA, indicating a cholinergic contribution to these responses at all ages. Intravenous thiorphan, a known NEP inhibitor, potentiated the effects of SP only in 2- to 3- and 10-wk-old piglets and did not affect the response of tracheal tension to NKA at any age. Biochemical analyses demonstrated a significant increase in tracheal NEP activity in comparably aged piglets over the first 10 wk of life.(ABSTRACT TRUNCATED AT 250 WORDS)

Involvement of substance P in neutral endopeptidase modulation of carotid body sensory responses to hypoxia.

PubMed

Kumar, G K; Kou, Y R; Overholt, J L; Prabhakar, N R

2000-01-01

Previously, we showed that carotid bodies express neutral endopeptidase (NEP)-like enzyme activity and that phosphoramidon, a potent inhibitor of NEP, potentiates the chemosensory response of the carotid body to hypoxia in vivo. NEP has been shown to hydrolyze methionine enkephalin (Met-Enk) and substance P (SP) in neuronal tissues. The purpose of the present study is to determine whether NEP hydrolyzes Met-Enk and SP in the carotid body and if so whether these peptides contribute to phosphoramidon-induced potentiation of the sensory response to hypoxia. Experiments were performed on carotid bodies excised from anesthetized adult cats (n = 72 carotid bodies). The hydrolysis of Met-Enk and SP was analyzed by HPLC. The results showed that both SP and Met-Enk were hydrolyzed by the carotid body, but the rate of Met-Enk hydrolysis was approximately fourfold higher than that of SP. Phosphoramidon (400 microM) markedly inhibited SP hydrolysis ( approximately 90%) but had only a marginal effect on Met-Enk hydrolysis ( approximately 15% inhibition). Hypoxia (PO(2), 68 +/- 6 Torr) as well as exogenous administration of SP (10 and 20 nmol) increased the sensory discharge of the carotid body in vitro. Sensory responses to hypoxia and SP (10 nmol) were potentiated by approximately 80 and approximately 275%, respectively (P < 0.01), in the presence of phosphoramidon. SP-receptor antagonists Spantide (peptidyl) and CP-96345 (nonpeptidyl) either abolished or markedly attenuated the phosphoramidon-induced potentiation of the sensory response of the carotid body to hypoxia as well as to SP. These results demonstrate that SP is a preferred substrate for NEP in the carotid body and that SP is involved in the potentiation of the hypoxic response of the carotid body by phosphoramidon.

Social and structural factors associated with HIV infection among female sex workers who inject drugs in the Mexico-US border region.

PubMed

Strathdee, Steffanie A; Lozada, Remedios; Martinez, Gustavo; Vera, Alicia; Rusch, Melanie; Nguyen, Lucie; Pollini, Robin A; Uribe-Salas, Felipe; Beletsky, Leo; Patterson, Thomas L

2011-04-25

FSWs who inject drugs (FSW-IDUs) can acquire HIV through high risk sexual and injection behaviors. We studied correlates of HIV infection among FSW-IDUs in northern Mexico, where sex work is quasi-legal and syringes can be legally obtained without a prescription. FSW-IDUs>18 years old who reported injecting drugs and recent unprotected sex with clients in Tijuana and Ciudad Juarez underwent surveys and HIV/STI testing. Logistic regression identified correlates of HIV infection. Of 620 FSW-IDUs, prevalence of HIV, gonorrhea, Chlamydia, trichomonas, syphilis titers ≥1:8, or any of these infections was 5.3%, 4%, 13%, 35%, 10% and 72%, respectively. Compared to other FSW-IDUs, HIV-positive women were more likely to: have syphilis titers ≥1:8 (36% vs. 9%, p<0.001), often/always inject drugs with clients (55% vs. 32%, p = 0.01), and experience confiscation of syringes by police (49% vs. 28%, p = 0.02). Factors independently associated with HIV infection were syphilis titers ≥1:8, often/always injecting with clients and police confiscation of syringes. Women who obtained syringes from NEPs (needle exchange programs) within the last month had lower odds of HIV infection associated with active syphilis, but among non-NEP attenders, the odds of HIV infection associated with active syphilis was significantly elevated. Factors operating in both the micro-social environment (i.e., injecting drugs with clients) and policy environment (i.e., having syringes confiscated by police, attending NEPs) predominated as factors associated with risk of HIV infection, rather than individual-level risk behaviors. Interventions should target unjustified policing practices, clients' risk behaviors and HIV/STI prevention through NEPs.

Amide-to-triazole switch vs. in vivo NEP-inhibition approaches to promote radiopeptide targeting of GRPR-positive tumors.

PubMed

Maina, Theodosia; Kaloudi, Aikaterini; Valverde, Ibai E; Mindt, Thomas L; Nock, Berthold A

2017-09-01

Radiolabeled bombesin (BBN)-analogs have been proposed for diagnosis and therapy of gastrin-releasing peptide receptor (GRPR)-expressing tumors, such as prostate, breast and lung cancer. Metabolic stability represents a crucial factor for the success of this approach by ensuring sufficient delivery of circulating radioligand to tumor sites. The amide-to-triazole switch on the backbone of DOTA-PEG 4 -[Nle 14 ]BBN(7-14) (1) was reported to improve the in vitro stability of resulting 177 Lu-radioligands. On the other hand, in-situ inhibition of neutral endopeptidase (NEP) by coinjection of phosphoramidon (PA) was shown to significantly improve the in vivo stability and tumor uptake of biodegradable radiopeptides. We herein compare the impact of the two methods on the bioavailability and localization of 177 Lu-DOTA-PEG 4 -[Nle 14 ]BBN(7-14) analogs in GRPR-positive tumors in mice. The 1,4-disubstituted [1-3]-triazole was used to replace one (2: Gly 11 -His 12 ; 3: Ala 9 -Val 10 ) or two (4: Ala 9 -Val 10 and Gly 11 -His 12 ) peptide bonds in 1 (reference) and all compounds were labeled with 177 Lu. Each of [ 177 Lu]1-[ 177 Lu]4 was injected without (control) or with PA in healthy mice. Blood samples collected 5min post-injection (pi) were analyzed by HPLC. Biodistribution of [ 177 Lu]1-[ 177 Lu]4 was conducted in SCID mice bearing human prostate adenocarcinoma PC-3 xenografts at 4h pi. Groups of 4 animals were injected with radioligand, alone (controls), or with coinjection of PA, or of a mixture of PA and excess and [Tyr 4 ]BBN to determine GRPR-specificity of uptake (Block). The in vivo stability of the radioligands was: [ 177 Lu]1 (25% intact), [ 177 Lu]2 (45% intact), [ 177 Lu]3 (30% intact) and [ 177 Lu]4 (40% intact). By PA-coinjection these values notably increased to 90%-93%. Moreover, treatment with PA induced an impressive and GRPR-specific uptake of all radioligands in the PC-3 xenografts at 4h pi: [ 177 Lu]1: 4.7±0.4 to 24.8±4.9%ID/g; [ 177 Lu]2: 8.3±1

Properties of Dust Obscured Galaxies in the Nep-Deep Field

NASA Astrophysics Data System (ADS)

Oi, Nagisa; Matsuhara, Hideo; Pearson, Chris; Buat, Veronique; Burgarella, Denis; Malkan, Matt; Miyaji, Takamitsu; AKARI-NEP Team

2017-03-01

We selected 47 DOGs at z∼1.5 using optical R (or r^{'}), AKARI 18 μm, and 24 μm color in the AKARI North Ecliptic Pole (NEP) Deep survey field. Using the colors among 3, 4, 7, and 9μm, we classified them into 3 groups; bump DOGs (23 sources), power-law DOGs (16 sources), and unknown DOGs (8 sources). We built spectral energy distributions (SEDs) with optical to far-infrared photometric data and investigated their properties using SED fitting method. We found that AGN activity such as a AGN contribution to the infrared luminosity and a Chandra detection rate for bump and power-law DOGs are significantly different, while stellar component properties like a stellar mass and a star-formation rate are similar to each other. A specific star-formation rate range of power-law DOGs is slightly higher than that of bump DOGs with wide overlap. Herschel/PACS detection rates are almost the same between bump and power-law DOGs. On the other hand SPIRE detection rates show large differences between bump and power-law DOGs. These results might be explained by differences in dust temperatures. Both groups of DOGs host hot and/or warm dust (∼ 50 Kelvin), and many bump DOGs contain cooler dust (≤ 30 Kelvin)

NK-1 receptor desensitization and neutral endopeptidase terminate SP-induced pancreatic plasma extravasation.

PubMed

Maa, J; Grady, E F; Kim, E H; Yoshimi, S K; Hutter, M M; Bunnett, N W; Kirkwood, K S

2000-10-01

Substance P (SP) induces plasma extravasation and neutrophil infiltration by activating the neurokinin-1 receptor (NK1-R). We characterized the mechanisms regulating this response in the rat pancreas. Anesthetized rats were continuously infused with SP, and plasma extravasation was quantified using Evans blue (EB) dye. Continuous infusion of SP (8 nmol. kg(-1). h(-1)) resulted in a threshold increase in EB at 15 min, a peak effect at 30 min (150% increase), and a return to baseline by 60 min. The NK1-R antagonist CP-96,345 blocked SP-induced plasma extravasation. After 60 min, the NK1-R was desensitized to agonist challenge. Resensitization was first detected at 20 min and increased until full recovery was seen at 30 min. Inhibition of the cell-surface protease neutral endopeptidase (NEP) by phosphoramidon potentiated the effect of exogenous SP; therefore endogenous NEP attenuates SP-induced plasma extravasation. Thus the continuous infusion of SP stimulates plasma extravasation in the rat pancreas via activation of the NK1-R, and these effects are terminated by both desensitization of the NK1-R and the cell-surface protease NEP.

Use of Land Use Land Cover Change Mapping Products in Aiding Coastal Habitat Conservation and Restoration Efforts of the Mobile Bay NEP

NASA Technical Reports Server (NTRS)

Spruce, Joseph P.; Swann, Roberta; Smooth, James

2010-01-01

The Mobile Bay region has undergone significant land use land cover change (LULC) over the last 35 years, much of which is associated with urbanization. These changes have impacted the region s water quality and wildlife habitat availability. In addition, much of the region is low-lying and close to the Gulf, which makes the region vulnerable to hurricanes, climate change (e.g., sea level rise), and sometimes man-made disasters such as the Deepwater Horizon (DWH) oil spill. Land use land cover change information is needed to help coastal zone managers and planners to understand and mitigate the impacts of environmental change on the region. This presentation discusses selective results of a current NASA-funded project in which Landsat data over a 34-year period (1974-2008) is used to produce, validate, refine, and apply land use land cover change products to aid coastal habitat conservation and restoration needs of the Mobile Bay National Estuary Program (MB NEP). The project employed a user defined classification scheme to compute LULC change mapping products for the entire region, which includes the majority of Mobile and Baldwin counties. Additional LULC change products have been computed for select coastal HUC-12 sub-watersheds adjacent to either Mobile Bay or the Gulf of Mexico, as part of the MB NEP watershed profile assessments. This presentation will include results of additional analyses of LULC change for sub-watersheds that are currently high priority areas, as defined by MB NEP. Such priority sub-watersheds include those that are vulnerable to impacts from the DWH oil spill, as well as sub-watersheds undergoing urbanization. Results demonstrating the nature and permanence of LULC change trends for these higher priority sub-watersheds and results characterizing change for the entire 34-year period and at approximate 10-year intervals across this period will also be presented. Future work will include development of value-added coastal habitat quality

Responses of the terrestrial carbon cycle to drought: modeling sensitivities of the interactive nitrogen and dynamic vegetation

NASA Astrophysics Data System (ADS)

Jia, B.; Wang, Y.; Xie, Z.

2016-12-01

Drought can trigger both immediate and time-lagged responses of terrestrial ecosystems and even cause sizeable positive feedbacks to climate warming. In this study, the influences of interactive nitrogen (N) and dynamic vegetation (DV) on the response of the carbon cycle in terrestrial ecosystems of China to drought were investigated using the Community Land Model version 4.5 (CLM4.5). Model simulations from three configurations of CLM4.5 (C, carbon cycle only; CN, dynamic carbon and nitrogen cycle; CNDV, dynamic carbon and nitrogen cycle as well as dynamic vegetation) between 1961 and 2010 showed that the incorporation of a prognostic N cycle and DV into CLM4.5 reduce the predicted annual means and inter-annual variability of predicted gross primary production (GPP) and net ecosystem production (NEP), except for a slight increase in NEP for CNDV compared to CN. These model improvements resulted in better agreement with observations (7.0 PgC yr-1) of annual GPP over the terrestrial ecosystems in China for CLM45-CN (7.5 PgC yr-1) and CLM45-CNDV (7.3 PgC yr-1) than for CLM45-C (10.9 PgC yr-1). Compared to the CLM45-C, the carbon-nitrogen coupling strengthened the predicted response of GPP to drought, resulting in a higher correlation with the standardized precipitation index (SPI; rC = 0.62, rCN = 0.67), but led to a weaker sensitivity of NEP to SPI (rC = 0.51, rCN = 0.45). The CLM45-CNDV had the longest lagged responses of GPP to drought among the three configurations. These results enhance our understanding of the response of the terrestrial carbon cycle to drought.

Role of endothelin-converting enzyme, chymase and neutral endopeptidase in the processing of big ET-1, ET-1(1-21) and ET-1(1-31) in the trachea of allergic mice.

PubMed

De Campo, Benjamin A; Goldie, Roy G; Jeng, Arco Y; Henry, Peter J

2002-08-01

The present study examined the roles of endothelin-converting enzyme (ECE), neutral endopeptidase (NEP) and mast cell chymase as processors of the endothelin (ET) analogues ET-1(1-21), ET-1(1-31) and big ET-1 in the trachea of allergic mice. Male CBA/CaH mice were sensitized with ovalbumin (10 microg) delivered intraperitoneal on days 1 and 14, and exposed to aerosolized ovalbumin on days 14, 25, 26 and 27 (OVA mice). Mice were killed and the trachea excised for histological analysis and contraction studies on day 28. Tracheae from OVA mice had 40% more mast cells than vehicle-sensitized mice (sham mice). Ovalbumin (10 microg/ml) induced transient contractions (15+/-3% of the C(max)) in tracheae from OVA mice. The ECE inhibitor CGS35066 (10 microM) inhibited contractions induced by big ET-1 (4.8-fold rightward shift of dose-response curve; P<0.05), but not those induced by either ET-1(1-21) or ET-1(1-31). The chymase inhibitors chymostatin (10 microM) and Bowman-Birk inhibitor (10 microM) had no effect on contractions induced by any of the ET analogues used. The NEP inhibitor CGS24592 (10 microM) inhibited contractions induced by ET-1(1-31) (6.2-fold rightward shift; P<0.05) but not ET-1(1-21) or big ET-1. These data suggest that big ET-1 is processed predominantly by a CGS35066-sensitive ECE within allergic airways rather than by mast cell-derived proteases such as chymase. If endogenous ET-1(1-31) is formed within allergic airways, it is likely to undergo further conversion by NEP to more active products.

Exploring the Use of the Revised New Ecological Paradigm Scale (NEP) to Monitor the Development of Students' Ecological Worldviews

ERIC Educational Resources Information Center

Harraway, John; Broughton-Ansin, Freya; Deaker, Lynley; Jowett, Tim; Shephard, Kerry

2012-01-01

Higher education institutions are interested in the impact that they and concurrent life experiences may have on students' sustainability attitudes, but they lack formal processes to monitor changes. We used the NEP to monitor changes in students' ecological-worldviews. We were interested in what variation there would be in a multidisciplinary…

Social and Structural Factors Associated with HIV Infection among Female Sex Workers Who Inject Drugs in the Mexico-US Border Region

PubMed Central

Strathdee, Steffanie A.; Lozada, Remedios; Martinez, Gustavo; Vera, Alicia; Rusch, Melanie; Nguyen, Lucie; Pollini, Robin A.; Uribe-Salas, Felipe; Beletsky, Leo; Patterson, Thomas L.

2011-01-01

Background FSWs who inject drugs (FSW-IDUs) can acquire HIV through high risk sexual and injection behaviors. We studied correlates of HIV infection among FSW-IDUs in northern Mexico, where sex work is quasi-legal and syringes can be legally obtained without a prescription. Methods FSW-IDUs>18 years old who reported injecting drugs and recent unprotected sex with clients in Tijuana and Ciudad Juarez underwent surveys and HIV/STI testing. Logistic regression identified correlates of HIV infection. Results Of 620 FSW-IDUs, prevalence of HIV, gonorrhea, Chlamydia, trichomonas, syphilis titers ≥1∶8, or any of these infections was 5.3%, 4%, 13%, 35%, 10% and 72%, respectively. Compared to other FSW-IDUs, HIV-positive women were more likely to: have syphilis titers ≥1∶8 (36% vs. 9%, p<0.001), often/always inject drugs with clients (55% vs. 32%, p = 0.01), and experience confiscation of syringes by police (49% vs. 28%, p = 0.02). Factors independently associated with HIV infection were syphilis titers ≥1∶8, often/always injecting with clients and police confiscation of syringes. Women who obtained syringes from NEPs (needle exchange programs) within the last month had lower odds of HIV infection associated with active syphilis, but among non-NEP attenders, the odds of HIV infection associated with active syphilis was significantly elevated. Conclusions Factors operating in both the micro-social environment (i.e., injecting drugs with clients) and policy environment (i.e., having syringes confiscated by police, attending NEPs) predominated as factors associated with risk of HIV infection, rather than individual-level risk behaviors. Interventions should target unjustified policing practices, clients' risk behaviors and HIV/STI prevention through NEPs. PMID:21541349

Absolute response and noise equivalent power of cyclotron resonance-assisted InSb detectors at submillimeter wavelengths

NASA Technical Reports Server (NTRS)

Brown, E. R.; Wengler, M. J.; Phillips, T. G.

1985-01-01

Spectra are presented of the responsivity and noise equivalent power (NEP) of liquid-helium-cooled InSb detectors as a function of magnetic field in the range 20-110 per cm. The measurements are all made using a Fourier transform spectrometer with thermal sources. The results show a discernable peak in the detector response at the conduction electron cyclotron resonance (CCR) frequency for magnetic fields as low as 3 kG. The magnitude of responsivity at the resonance peaks is roughly constant with magnetic field and is comparable to the low-frequency hot-electron bolometer response. The NEP at the peaks is found to be comparable to the best long wavelength results previously reported. For example, NEP = 4.5 x 10 to the 13th W/(square root of Hz) at 4.2 K, 6 kG, and 40 per cm was measured. The InSb CCR will provide a much improved detector for laboratory spectroscopy, as compared with hot electron bolometers, in the 20-100 per cm range.

A diagnostic carbon flux model to monitor the effects of disturbance and interannual variation in climate on regional NEP.

Treesearch

D.P. Turner; W.D. Ritts; J.M. Styles; Z. Yang; W.B. Cohen; B.E. Law; P.E. Thornton

2006-01-01

Net ecosystem production (NEP) was estimated over a 10.9 x 104 km2 forested region in western Oregon USA for 2 yr (2002-2003) using a combination of remote sensing, distributed meteorological data, and a carbon cycle model (CFLUX). High spatial resolution satellite data (Landsat, 30 m) provided information on land cover and...

ATF1 Modulates the Heat Shock Response by Regulating the Stress-Inducible Heat Shock Factor 1 Transcription Complex

PubMed Central

Takii, Ryosuke; Fujimoto, Mitsuaki; Tan, Ke; Takaki, Eiichi; Hayashida, Naoki; Nakato, Ryuichiro; Shirahige, Katsuhiko

2014-01-01

The heat shock response is an evolutionally conserved adaptive response to high temperatures that controls proteostasis capacity and is regulated mainly by an ancient heat shock factor (HSF). However, the regulation of target genes by the stress-inducible HSF1 transcription complex has not yet been examined in detail in mammalian cells. In the present study, we demonstrated that HSF1 interacted with members of the ATF1/CREB family involved in metabolic homeostasis and recruited them on the HSP70 promoter in response to heat shock. The HSF1 transcription complex, including the chromatin-remodeling factor BRG1 and lysine acetyltransferases p300 and CREB-binding protein (CBP), was formed in a manner that was dependent on the phosphorylation of ATF1. ATF1-BRG1 promoted the establishment of an active chromatin state and HSP70 expression during heat shock, whereas ATF1-p300/CBP accelerated the shutdown of HSF1 DNA-binding activity during recovery from acute stress, possibly through the acetylation of HSF1. Furthermore, ATF1 markedly affected the resistance to heat shock. These results revealed the unanticipated complexity of the primitive heat shock response mechanism, which is connected to metabolic adaptation. PMID:25312646

High Power MPD Nuclear Electric Propulsion (NEP) for Artificial Gravity HOPE Missions to Callisto

NASA Technical Reports Server (NTRS)

McGuire, Melissa L.; Borowski, Stanley K.; Mason, Lee M.; Gilland, James

2003-01-01

This documents the results of a one-year multi-center NASA study on the prospect of sending humans to Jupiter's moon, Callisto, using an all Nuclear Electric Propulsion (NEP) space transportation system architecture with magnetoplasmadynamic (MPD) thrusters. The fission reactor system utilizes high temperature uranium dioxide (UO2) in tungsten (W) metal matrix cermet fuel and electricity is generated using advanced dynamic Brayton power conversion technology. The mission timeframe assumes on-going human Moon and Mars missions and existing space infrastructure to support launch of cargo and crewed spacecraft to Jupiter in 2041 and 2045, respectively.

Progress report on understanding AFIS seed coat nep levels in pre-opened slivers on the Advanced Fiber Information System (AFIS)

USDA-ARS?s Scientific Manuscript database

The Advanced Fiber Information System (AFIS) is utilized in this segment of the research project to study how seed coat neps are measured. A patent search was conducted, and studied to assist with the understanding of the AFIS measurement of this impurity in raw cotton. The older AFIS 2 is primari...

Tachykinin receptor and neutral endopeptidase gene expression in the rat uterus: characterization and regulation in response to ovarian steroid treatment.

PubMed

Pinto, F M; Armesto, C P; Magraner, J; Trujillo, M; Martín, J D; Candenas, M L

1999-06-01

Tachykinin neuropeptides, such as substance P, are localized to a population of sensory fibers that innervate the mammalian female reproductive tract. In the present study, we have characterized tachykinin NK1 receptor (NK1R), NK2 receptor (NK2R), and NK3 receptor (NK3R) gene expression by semiquantitative RT-PCR in uteri from ovariectomized rats and studied their regulation in response to 17beta-estradiol (E2), progesterone (P4), or a combination of both. In addition, we analyzed the expression and regulation of the neutral endopeptidase 24.11 (NEP), the most important enzyme involved in tachykinin degradation in the rat uterus. In uteri from control (olive oil-treated) rats, RT-PCR assays revealed single bands corresponding to the expected product sizes encoding complementary DNA for NK1R (232 bp), NK2R (491 bp), NK3R (325 bp), and NEP (221 bp). The identity of the amplified fragments was confirmed by DNA sequence analysis. Compared with control rats, NK1R messenger RNA (mRNA) was increased by 2-fold in uteri from rats treated with E2, was decreased by 3.3-fold in rats treated with P4, and was decreased by 1.8-fold in rats treated with both E2 and P4. Uterine NK2R mRNA levels were not altered by any steroid treatment. E2 treatment decreased by 15-fold NK3R mRNA. P4 was without effect if administered alone and did not influence the E2-induced decrease in NK3R mRNA. NEP mRNA levels were about 4-fold lower in E2-treated than in P4-treated rats. Functional studies were carried out in uteri from E2- or P4-treated ovariectomized rats to characterize the contractile response evoked by the selective tachykinin receptor agonists [Sar9Met(O2)11]substance P (NK1R selective), [Nle10]NKA-(4-10) (NK2R selective), and [MePhe7]NKB (NK3R selective) in the presence of the NEP inhibitor phosphoramidon (1 microM). A marked correlation was observed between the magnitude of the contractile response to each agonist and the level of expression determined by RT-PCR for each tachykinin

The role of neutral endopeptidase in caerulein-induced acute pancreatitis.

PubMed

Koh, Yung-Hua; Moochhala, Shabbir; Bhatia, Madhav

2011-11-15

Substance P (SP) is well known to promote inflammation in acute pancreatitis (AP) by interacting with neurokinin-1 receptor. However, mechanisms that terminate SP-mediated responses are unclear. Neutral endopeptidase (NEP) is a cell-surface enzyme that degrades SP in the extracellular fluid. In this study, we examined the expression and the role of NEP in caerulein-induced AP. Male BALB/c mice (20-25 g) subjected to 3-10 hourly injections of caerulein (50 μg/kg) exhibited reduced NEP activity and protein expression in the pancreas and lungs. Additionally, caerulein (10(-7) M) also downregulated NEP activity and mRNA expression in isolated pancreatic acinar cells. The role of NEP in AP was examined in two opposite ways: inhibition of NEP (phosphoramidon [5 mg/kg] or thiorphan [10 mg/kg]) followed by 6 hourly caerulein injections) or supplementation with exogenous NEP (10 hourly caerulein injections, treatment of recombinant mouse NEP [1 mg/kg] during second caerulein injection). Inhibition of NEP raised SP levels and exacerbated inflammatory conditions in mice. Meanwhile, the severity of AP, determined by histological examination, tissue water content, myeloperoxidase activity, and plasma amylase activity, was markedly better in mice that received exogenous NEP treatment. Our results suggest that NEP is anti-inflammatory in caerulein-induced AP. Acute inhibition of NEP contributes to increased SP levels in caerulein-induced AP, which leads to augmented inflammatory responses in the pancreas and associated lung injury.

NECAP 4.1: NASA's Energy Cost Analysis Program thermal response factor routine

NASA Astrophysics Data System (ADS)

Weise, M. R.

1982-08-01

A thermal response factor is described and calculation sequences and flowcharts for RESFAC2 are provided. RESFAC is used by NASA's (NECAP) to calculate hourly heat transfer coefficients (thermal response factors) for each unique delayed surface. NECAP uses these response factors to compute each spaces' hourly heat gain/loss.

Transforming growth factor-beta1 mediates cellular response to DNA damage in situ

NASA Technical Reports Server (NTRS)

Ewan, Kenneth B.; Henshall-Powell, Rhonda L.; Ravani, Shraddha A.; Pajares, Maria Jose; Arteaga, Carlos; Warters, Ray; Akhurst, Rosemary J.; Barcellos-Hoff, Mary Helen

2002-01-01

Transforming growth factor (TGF)-beta1 is rapidly activated after ionizing radiation, but its specific role in cellular responses to DNA damage is not known. Here we use Tgfbeta1 knockout mice to show that radiation-induced apoptotic response is TGF-beta1 dependent in the mammary epithelium, and that both apoptosis and inhibition of proliferation in response to DNA damage decrease as a function of TGF-beta1 gene dose in embryonic epithelial tissues. Because apoptosis in these tissues has been shown previously to be p53 dependent, we then examined p53 protein activation. TGF-beta1 depletion, by either gene knockout or by using TGF-beta neutralizing antibodies, resulted in decreased p53 Ser-18 phosphorylation in irradiated mammary gland. These data indicate that TGF-beta1 is essential for rapid p53-mediated cellular responses that mediate cell fate decisions in situ.

Genetic Deficiency in Neprilysin or Its Pharmacological Inhibition Initiate Excessive Stress-Induced Alcohol Consumption in Mice

PubMed Central

Gembardt, Florian; Becker, Axel; Schultheiss, Heinz-Peter; Siems, Wolf-Eberhard; Walther, Thomas

2012-01-01

Both acquired and inherited genetic factors contribute to excessive alcohol consumption and the corresponding development of addiction. Here we show that the genetic deficiency in neprilysin [NEP] did not change the kinetics of alcohol degradation but led to an increase in alcohol intake in mice in a 2-bottle-free-choice paradigm after one single stress stimulus (intruder). A repetition of such stress led to an irreversible elevated alcohol consumption. This phenomenon could be also observed in wild-type mice receiving an orally active NEP inhibitor. We therefore elucidated the stress behavior in NEP-deficient mice. In an Elevated Plus Maze, NEP knockouts crossed more often the area between the arms, implicating a significant stronger stress response. Furthermore, such animals showed a decreased locomotor activity under intense light in a locomotor activity test, identifying such mice to be more responsive in aversive situations than their wild-type controls. Since the reduction in NEP activity itself does not lead to significant signs of an altered alcohol preference in mice but requires an environmental stimulus, our findings build a bridge between stress components and genetic factors in the development of alcoholism. Therefore, targeting NEP activity might be a very attractive approach for the treatment of alcohol abuse in a society with increasing social and financial stress. PMID:23185571

Expression of a transmembrane phosphotyrosine phosphatase inhibits cellular response to platelet-derived growth factor and insulin-like growth factor-1.

PubMed

Mooney, R A; Freund, G G; Way, B A; Bordwell, K L

1992-11-25

Tyrosine phosphorylation is a mechanism of signal transduction shared by many growth factor receptors and oncogene products. Phosphotyrosine phosphatases (PTPases) potentially modulate or counter-regulate these signaling pathways. To test this hypothesis, the transmembrane PTPase CD45 (leukocyte common antigen) was expressed in the murine cell line C127. Hormone-dependent autophosphorylation of the platelet-derived growth factor (PDGF) and insulin-like growth factor-1 (IGF-1) receptors was markedly reduced in cells expressing the transmembrane PTPase. Tyrosine phosphorylation of other PDGF-dependent phosphoproteins (160, 140, and 55 kDa) and IGF-1-dependent phosphoproteins (145 kDa) was similarly decreased. Interestingly, the pattern of growth factor-independent tyrosine phosphorylations was comparable in cells expressing the PTPase and control cells. This suggests a selectivity or accessibility of the PTPase limited to a subset of cellular phosphotyrosyl proteins. The maximum mitogenic response to PDGF and IGF-1 in cells expressing the PTPase was decreased by 67 and 71%, respectively. These results demonstrate that a transmembrane PTPase can both affect the tyrosine phosphorylation state of growth factor receptors and modulate proximal and distal cellular responses to the growth factors.

Predictors of needle exchange program utilization during its implementation and expansion in Tijuana, Mexico.

PubMed

Smith, Danielle M; Werb, Dan; Abramovitz, Daniela; Magis-Rodriguez, Carlos; Vera, Alicia; Patterson, Thomas L; Strathdee, Steffanie A

2016-03-01

Until the early 2000s, there was only one needle exchange program (NEP) offered in Mexico. In 2004, the second Mexican NEP opened in Tijuana, but its utilization has not been studied. We studied predictors of initiating NEP during its early expansion in Tijuana, Mexico. From April 2006 to April 2007, people who inject drugs (PWID) residing in Tijuana who had injected within the last month were recruited using respondent-driven sampling. Weighted Poisson regression incorporating generalized estimating equations was used to identify predictors of initiating NEP, while accounting for correlation between recruiter and recruits. NEP uptake increased from 20% at baseline to 59% after 6 months. Among a subsample of PWID not accessing NEP at baseline (n = 480), 83% were male and median age was 37 years (Interquartile Range: 32-43). At baseline, 4.4% were HIV-infected and 5.9% had syphilis titers >1:8. In multivariate models, factors associated with NEP initiation (p < .05) were attending shooting galleries (Adjusted Relative Risk [ARR]: 1.54); arrest for track-marks (ARR: 1.38); having a family member that ever used drugs (ARR: 1.37); and having a larger PWID network (ARR: 1.01 per 10 persons). NEP initiation was inversely associated with obtaining syringes at pharmacies (ARR: .56); earning >2500 pesos/month (ARR: .66); and reporting needle sharing (ARR: .71). Uptake of NEP expansion in Tijuana was vigorous among PWID. We identified a range of factors that influenced the likelihood of NEP initiation, including police interaction. These findings have important implications for the scale-up of NEP in Mexico. © American Academy of Addiction Psychiatry.

Sensory neuropeptides modulate cigarette smoke-induced decrease in neutral endopeptidase activity in guinea pig airways.

PubMed

Kuo, H P; Lu, L C

1995-01-01

Cigarette smoke (CS) inhalation stimulates C-fibers to release sensory neuropeptides which mediate airway reflex responses to prevent irritants from entering the lower airways. When CS is inhaled via the upper airways, these airway defense responses may modulate the effect of CS on airway NEP activity and related airway hyperresponsiveness. To examine this possibility, we exposed guinea pigs to 1:10 diluted mid-tar cigarette smoke 100 puffs per day for 7 days and recorded pulmonary resistance of cumulative doses of neurokinin A (NKA, 10(-12)-10(-8) mol/kg, i.v.) or methacholine (Mch, 1-50 micrograms/kg, i.v.). NEP activity in the tracheobronchi was measured using fluorometric assay. Exposure of CS alone failed to alter the dose-response to NKA or Mch compared with air control. NEP activity in the airways after CS exposure was slightly but significantly lower than that of air control. Capsaicin pretreatment 1 week before CS exposure significantly shifted the dose-response curves of NKA, but not Mch, to the left and decreased NEP activity in the airways to a greater extent compared with CS exposure alone group. Capsaicin pretreatment alone failed to alter the responsiveness to NKA or NEP activity. CS also induced a significant increase in neutrophil counts in airways. Capsaicin pretreatment enhanced the effect of CS on neutrophil recruitment. We conclude that sensory neuropeptides may have a protective role in modulation of airways NEP activity downregulation induced by CS, probably by preventing CS from entering the lower airways or the chronic release of sensory neuropeptides induced by CS providing increased amount of substrata for NEP upregulation, and therefore modify the direct effect of CS on NEP activity and related airway hyperresponsiveness.

Degradative enzymes modulate airway responses to intravenous neurokinins A and B.

PubMed

Shore, S A; Drazen, J M

1989-12-01

We studied the effects of the neutral endopeptidase (NEP) inhibitor thiorphan (1.7 mg/kg iv) and the angiotensin-converting enzyme (ACE) inhibitor captopril (5.7 mg/kg iv) on airway responses to rapid intravenous infusions of neurokinin A (NKA) and neurokinin B (NKB) in anesthetized, mechanically ventilated guinea pigs. The dose of NKA required to decrease pulmonary conductance to 50% of its base-line value (ED50GL) was fivefold less (P less than 0.0001) in animals treated with thiorphan compared with controls. NKA1-8, a product resulting from cleavage of NKA by NEP, had no bronchoconstrictor activity. Similar results were obtained by using NKB as the bronchoconstricting agent. Captopril had no significant effect on airway responses to NKA or NKB. In contrast, both thiorphan and captopril decrease the ED50GL for substance P (SP). We also compared the relative bronchoconstrictor potency of NKA, NKB, and SP. In control animals, the rank order of ED50GL values was NKA much less than NKB = SP. NKA also caused a more prolonged bronchoconstriction than SP or NKB. Thiorphan had no effect on the rank order of bronchoconstrictor potency, but in animals treated with captopril, the rank order of ED50GL values was altered to NKA less than SP less than NKB. These results suggest that degradation of NKA and NKB by NEP but not by ACE is an important determinant of the bronchoconstriction induced by these peptides. The degradation by ACE of SP but not NKA or NKB influences the observed relative potency of the three tachykinins as bronchoactive agents.

Energy utilisation of broiler chickens in response to guanidinoacetic acid supplementation in diets with various energy contents.

PubMed

Ale Saheb Fosoul, Sayed Sadra; Azarfar, Arash; Gheisari, Abbasali; Khosravinia, Heshmatollah

2018-07-01

This experiment was conducted to investigate the effects of guanidinoacetic acid (GAA) on productive performance, intestinal morphometric features, blood parameters and energy utilisation in broiler chickens. A total of 390 male broiler chicks (Ross 308) were assigned to six dietary treatments based on a factorial arrangement (2×3) across 1-15 and 15-35-d periods. Experimental treatments consisted of two basal diets with standard (STD; starter: 12·56 MJ/kg and grower: 12·97 MJ/kg) and reduction (LME; starter: 11·93 MJ/kg and grower: 12·33 MJ/kg) of apparent metabolisable energy (AME) requirement of broiler chickens each supplemented with 0, 0·6 and 1·2 g/kg GAA. Supplemental 1·2 g/kg GAA decreased the negative effects of feed energy reduction on weight gain across starter, growing and the entire production phases (P<0·05). Energy retention as fat and total energy retention were increased when birds received LME diets supplemented with 1·2 g/kg GAA (P<0·05). Net energy for production (NEp) and total heat production increased in birds fed LME diets containing 1·2 g/kg GAA (P<0·05). A significant correlation was observed between dietary NEp and weight gain of broilers (r 0·493; P=0·0055), whereas this relationship was not seen with AME. Jejunal villus height and crypt depth were lower in birds fed LME diets (P<0·05). Serum concentration of creatinine increased in broilers fed LME diets either supplemented with 1·2 g/kg GAA or without GAA supplementation (P<0·05). Supplemental GAA improved performance of chickens fed LME diet possibly through enhanced dietary NEp. The NEp could be preferred over the AME to assess response of broiler chickens to dietary GAA supplementation.

Increased actin polymerization reduces the inhibition of serum response factor activity by Yin Yang 1.

PubMed Central

Ellis, Peter D; Martin, Karen M; Rickman, Colin; Metcalfe, James C; Kemp, Paul R

2002-01-01

Recent evidence has implicated CC(A/T(richG))GG (CArG) boxes, binding sites for serum response factor (SRF), in the regulation of expression of a number of genes in response to changes in the actin cytoskeleton. In many cases, the activity of SRF at CArG boxes is modulated by transcription factors binding to overlapping (e.g. Yin Yang 1, YY1) or adjacent (e.g. ets) binding sites. However, the mechanisms by which SRF activity is regulated by the cytoskeleton have not been determined. To investigate these mechanisms, we screened for cells that did or did not increase the activity of a fragment of the promoter for a smooth-muscle (SM)-specific gene SM22alpha, in response to changes in actin cytoskeletal polymerization induced by LIM kinase. These experiments showed that vascular SM cells (VSMCs) and C2C12 cells increased the activity of promoters containing at least one of the SM22alpha CArG boxes (CArG near) in response to LIM kinase, whereas P19 cells did not. Bandshift assays using a probe to CArG near showed that P19 cells lacked detectable YY1 DNA binding to the CArG box in contrast with the other two cell types. Expression of YY1 in P19 cells inhibited SM22alpha promoter activity and conferred responsiveness to LIM kinase. Mutation of the CArG box to inhibit YY1 or SRF binding indicated that both factors were required for the LIM kinase response in VSMCs and C2C12 cells. The data indicate that changes in the actin cytoskeletal organization modify SRF activity at CArG boxes by modulating YY1-dependent inhibition. PMID:12023898

Inhibition of neutral endopeptidase increases airway responsiveness to ACh in nonsensitized normal rats.

PubMed

Chiba, Y; Misawa, M

1995-02-01

The effects of sensory neuropeptides on the airway responsiveness to acetylcholine (ACh) were investigated in normal nonsensitized rats. The airway responsiveness to inhaled ACh was significantly increased after treatment with neurokinin A (NKA; 0.001%) or substance P (SP; 0.01%) aerosol in the presence of the neutral endopeptidase (NEP) inhibitor. NKA had a more potent effect than SP. Interestingly, the intravenous treatment with NEP inhibitor alone also induced airway hyperresponsiveness (AHR) to inhaled ACh. This AHR was significantly attenuated by pretreatment with a nonselective NK-receptor antagonist, [D-Pro2,D-Trp7,9]SP, systemic capsaicin, or bilateral cervical vagotomy, indicating that decreased NEP activity results in accumulation of endogenous sensory neuropeptide(s) and enhancement of vagal reflex to cause AHR. The airway responsiveness to ACh of isolated left main bronchus was also increased after treatment with 10(-6) M NKA, but not SP, together with 10(-6) M phosphoramidon. This in vitro AHR to ACh induced by phosphoramidon plus NKA was significantly attenuated by pretreatment with 10(-6) M tetrodotoxin. These findings suggest that overaccumulated sensory neuropeptides, especially NKA, may enhance the probability of transmitter release, probably via NK2 receptors, and that the enhanced transmitter release might be involved in AHR in rats.

The Rice E3-Ubiquitin Ligase HIGH EXPRESSION OF OSMOTICALLY RESPONSIVE GENE1 Modulates the Expression of ROOT MEANDER CURLING, a Gene Involved in Root Mechanosensing, through the Interaction with Two ETHYLENE-RESPONSE FACTOR Transcription Factors1

PubMed Central

Lourenço, Tiago F.; Serra, Tânia S.; Cordeiro, André M.; Swanson, Sarah J.; Gilroy, Simon; Saibo, Nelson J.M.; Oliveira, M. Margarida

2015-01-01

Plant roots can sense and respond to a wide diversity of mechanical stimuli, including touch and gravity. However, little is known about the signal transduction pathways involved in mechanical stimuli responses in rice (Oryza sativa). This work shows that rice root responses to mechanical stimuli involve the E3-ubiquitin ligase rice HIGH EXPRESSION OF OSMOTICALLY RESPONSIVE GENE1 (OsHOS1), which mediates protein degradation through the proteasome complex. The morphological analysis of the roots in transgenic RNA interference::OsHOS1 and wild-type plants, exposed to a mechanical barrier, revealed that the OsHOS1 silencing plants keep a straight root in contrast to wild-type plants that exhibit root curling. Moreover, it was observed that the absence of root curling in response to touch can be reverted by jasmonic acid. The straight root phenotype of the RNA interference::OsHOS1 plants was correlated with a higher expression rice ROOT MEANDER CURLING (OsRMC), which encodes a receptor-like kinase characterized as a negative regulator of rice root curling mediated by jasmonic acid. Using the yeast two-hybrid system and bimolecular fluorescence complementation assays, we showed that OsHOS1 interacts with two ETHYLENE-RESPONSE FACTOR transcription factors, rice ETHYLENE-RESPONSIVE ELEMENT BINDING PROTEIN1 (OsEREBP1) and rice OsEREBP2, known to regulate OsRMC gene expression. In addition, we showed that OsHOS1 affects the stability of both transcription factors in a proteasome-dependent way, suggesting that this E3-ubiquitin ligase targets OsEREBP1 and OsEREBP2 for degradation. Our results highlight the function of the proteasome in rice response to mechanical stimuli and in the integration of these signals, through hormonal regulation, into plant growth and developmental programs. PMID:26381316

The Bartonella quintana Extracytoplasmic Function Sigma Factor RpoE Has a Role in Bacterial Adaptation to the Arthropod Vector Environment

PubMed Central

Abromaitis, Stephanie

2013-01-01

Bartonella quintana is a vector-borne bacterial pathogen that causes fatal disease in humans. During the infectious cycle, B. quintana transitions from the hemin-restricted human bloodstream to the hemin-rich body louse vector. Because extracytoplasmic function (ECF) sigma factors often regulate adaptation to environmental changes, we hypothesized that a previously unstudied B. quintana ECF sigma factor, RpoE, is involved in the transition from the human host to the body louse vector. The genomic context of B. quintana rpoE identified it as a member of the ECF15 family of sigma factors found only in alphaproteobacteria. ECF15 sigma factors are believed to be the master regulators of the general stress response in alphaproteobacteria. In this study, we examined the B. quintana RpoE response to two stressors that are encountered in the body louse vector environment, a decreased temperature and an increased hemin concentration. We determined that the expression of rpoE is significantly upregulated at the body louse (28°C) versus the human host (37°C) temperature. rpoE expression also was upregulated when B. quintana was exposed to high hemin concentrations. In vitro and in vivo analyses demonstrated that RpoE function is regulated by a mechanism involving the anti-sigma factor NepR and the response regulator PhyR. The ΔrpoE ΔnepR mutant strain of B. quintana established that RpoE-mediated transcription is important in mediating the tolerance of B. quintana to high hemin concentrations. We present the first analysis of an ECF15 sigma factor in a vector-borne human pathogen and conclude that RpoE has a role in the adaptation of B. quintana to the hemin-rich arthropod vector environment. PMID:23564167

FOREVER YOUNG FLOWER Negatively Regulates Ethylene Response DNA-Binding Factors by Activating an Ethylene-Responsive Factor to Control Arabidopsis Floral Organ Senescence and Abscission1

PubMed Central

Li, Pei-Fang; Lee, Yung-I; Yang, Chang-Hsien

2015-01-01

In this study of Arabidopsis (Arabidopsis thaliana), we investigated the relationship between FOREVER YOUNG FLOWER (FYF) and Ethylene Response DNA-binding Factors (EDFs) and functionally analyzed a key FYF target, an Ethylene-Responsive Factor (ERF), that controls flower senescence/abscission. Ectopic expression of EDF1/2/3/4 caused promotion of flower senescence/abscission and the activation of the senescence-associated genes. The presence of a repressor domain in EDFs and the enhancement of the promotion of senescence/abscission in EDF1/2/3/4+SRDX (converting EDFs to strong repressors by fusion with the ERF-associated amphiphilic repression motif repression domain SRDX) transgenic plants suggested that EDFs act as repressors. The significant reduction of β-glucuronidase (GUS) expression by 35S:FYF in EDF1/2/3/4:GUS plants indicates that EDF1/2/3/4 functions downstream of FYF in regulating flower senescence/abscission. In this study, we also characterized an ERF gene, FOREVER YOUNG FLOWER UP-REGULATING FACTOR1 (FUF1), which is up-regulated by FYF during flower development. Ectopic expression of FUF1 caused similar delayed flower senescence/abscission as seen in 35S:FYF plants. This phenotype was correlated with deficient abscission zone formation, ethylene insensitivity, and down-regulation of EDF1/2/3/4 and abscission-associated genes in 35S:FUF1 flowers. In contrast, significant promotion of flower senescence/abscission and up-regulation of EDF1/2/3/4 were observed in 35S:FUF1+SRDX transgenic dominant-negative plants, in which FUF1 is converted to a potent repressor by fusion to an SRDX-suppressing motif. Thus, FUF1 acts as an activator in suppressing EDF1/2/3/4 function and senescence/abscission of the flowers. Our results reveal that FYF regulates flower senescence/abscission by negatively regulating EDF1/2/3/4, which is the downstream gene in the ethylene response, by activating FUF1 in Arabidopsis. PMID:26063506

The Ethylene Responsive Factor Required for Nodulation 1 (ERN1) Transcription Factor Is Required for Infection-Thread Formation in Lotus japonicus.

PubMed

Kawaharada, Yasuyuki; James, Euan K; Kelly, Simon; Sandal, Niels; Stougaard, Jens

2017-03-01

Several hundred genes are transcriptionally regulated during infection-thread formation and development of nitrogen-fixing root nodules. We have characterized a set of Lotus japonicus mutants impaired in root-nodule formation and found that the causative gene, Ern1, encodes a protein with a characteristic APETALA2/Ethylene Responsive Factor (AP2/ERF) transcription-factor domain. Phenotypic characterization of four ern1 alleles shows that infection pockets are formed but root-hair infection threads are absent. Formation of root-nodule primordia is delayed and no normal transcellular infection threads are found in the infected nodules. Corroborating the role of ERN1 (ERF Required for Nodulation1) in nodule organogenesis, spontaneous nodulation induced by an autoactive CCaMK and cytokinin-induced nodule primordia were not observed in ern1 mutants. Expression of Ern1 is induced in the susceptible zone by Nod factor treatment or rhizobial inoculation. At the cellular level, the pErn1:GUS reporter is highly expressed in root epidermal cells of the susceptible zone and in the cortical cells that form nodule primordia. The genetic regulation of this cellular expression pattern was further investigated in symbiotic mutants. Nod factor induction of Ern1 in epidermal cells was found to depend on Nfr1, Cyclops, and Nsp2 but was independent of Nin and Nf-ya1. These results suggest that ERN1 functions as a transcriptional regulator involved in the formation of infection threads and development of nodule primordia and may coordinate these two processes.

Rice homeobox transcription factor HOX1a positively regulates gibberellin responses by directly suppressing EL1.

PubMed

Wen, Bi-Qing; Xing, Mei-Qing; Zhang, Hua; Dai, Cheng; Xue, Hong-Wei

2011-11-01

Homeobox transcription factors are involved in various aspects of plant development, including maintenance of the biosynthesis and signaling pathways of different hormones. However, few direct targets of homeobox proteins have been identified. We here show that overexpression of rice homeobox gene HOX1a resulted in enhanced gibberellin (GA) response, indicating a positive effect of HOX1a in GA signaling. HOX1a is induced by GA and encodes a homeobox transcription factor with transcription repression activity. In addition, HOX1a suppresses the transcription of early flowering1 (EL1), a negative regulator of GA signaling, and further electrophoretic mobility shift assay and chromatin immunoprecipitation analysis revealed that HOX1a directly bound to the promoter region of EL1 to suppress its expression and stimulate GA signaling. These results demonstrate that HOX1a functions as a positive regulator of GA signaling by suppressing EL1, providing informative hints on the study of GA signaling. © 2011 Institute of Botany, Chinese Academy of Sciences.

Heat shock factor-1 modulates p53 activity in the transcriptional response to DNA damage

PubMed Central

Logan, Ian R.; McNeill, Hesta V.; Cook, Susan; Lu, Xiaohong; Meek, David W.; Fuller-Pace, Frances V.; Lunec, John; Robson, Craig N.

2009-01-01

Here we define an important role for heat shock factor 1 (HSF1) in the cellular response to genotoxic agents. We demonstrate for the first time that HSF1 can complex with nuclear p53 and that both proteins are co-operatively recruited to p53-responsive genes such as p21. Analysis of natural and synthetic cis elements demonstrates that HSF1 can enhance p53-mediated transcription, whilst depletion of HSF1 reduces the expression of p53-responsive transcripts. We find that HSF1 is required for optimal p21 expression and p53-mediated cell-cycle arrest in response to genotoxins while loss of HSF1 attenuates apoptosis in response to these agents. To explain these novel properties of HSF1 we show that HSF1 can complex with DNA damage kinases ATR and Chk1 to effect p53 phosphorylation in response to DNA damage. Our data reveal HSF1 as a key transcriptional regulator in response to genotoxic compounds widely used in the clinical setting, and suggest that HSF1 will contribute to the efficacy of these agents. PMID:19295133

Neutral endopeptidase up-regulation in isolated human umbilical artery: involvement in desensitization of bradykinin-induced vasoconstrictor effects.

PubMed

Pelorosso, Facundo Germán; Halperin, Ana Verónica; Palma, Alejandro Martín; Nowak, Wanda; Errasti, Andrea Emilse; Rothlin, Rodolfo Pedro

2007-02-01

Previous reports show that bradykinin B(2) receptors mediate contractile responses induced by bradykinin (BK) in human umbilical artery (HUA). However, although it has been reported that BK-induced responses can desensitize in several inflammatory models, the effects of prolonged in vitro incubation on BK-induced vasoconstriction in HUA have not been studied. In isolated HUA rings, BK-induced responses after a 5-h in vitro incubation showed a marked desensitization compared with responses at 2 h. Inhibition of either angiotensin-converting enzyme (ACE) or neutral endopeptidase (NEP), both BK-inactivating enzymes, failed to modify responses to BK at 2 h. After 5 h, ACE inhibition produced only a slight potentiation of BK-induced responses. In contrast, BK-induced vasoconstriction at 5 h was markedly potentiated by NEP inhibition. Moreover, NEP activity, measured by hydrolysis of its synthetic substrate (Z-Ala-Ala-Leu-p-nitroanilide), showed a 2.4-fold increase in 5-h incubated versus 2-h incubated tissues, which was completely reversed by cycloheximide (CHX) treatment. Furthermore, CHX significantly potentiated BK-induced responses, suggesting that NEP-mediated kininase activity increase at 5 h depends on de novo protein synthesis. In addition, under NEP inhibition, CHX treatment failed to produce an additional potentiation of BK-induced vasoconstriction. Still, NEP up-regulation was confirmed by Western blot, showing a 2.1-fold increase in immunoreactive NEP in 5-h incubated versus 2-h incubated HUA. In summary, the present study provides strong pharmacological evidence that NEP is up-regulated and plays a key role in desensitization of BK-induced vasoconstriction after prolonged in vitro incubation in HUA. Our results provide new insights into the possible mechanisms involved in BK-induced response desensitization during sustained inflammatory conditions.

Interleukin 1 and Tumor Necrosis Factor Inhibit Cardiac Myocyte β -adrenergic Responsiveness

NASA Astrophysics Data System (ADS)

Gulick, Tod; Chung, Mina K.; Pieper, Stephen J.; Lange, Louis G.; Schreiner, George F.

1989-09-01

Reversible congestive heart failure can accompany cardiac allograft rejection and inflammatory myocarditis, conditions associated with an immune cell infiltrate of the myocardium. To determine whether immune cell secretory products alter cardiac muscle metabolism without cytotoxicity, we cultured cardiac myocytes in the presence of culture supernatants from activated immune cells. We observed that these culture supernatants inhibit β -adrenergic agonist-mediated increases in cultured cardiac myocyte contractility and intracellular cAMP accumulation. The myocyte contractile response to increased extracellular Ca2+ concentration is unaltered by prior exposure to these culture supernatants, as is the increase in myocyte intracellular cAMP concentration in response to stimulation with forskolin, a direct adenyl cyclase activator. Inhibition occurs in the absence of alteration in β -adrenergic receptor density or ligand binding affinity. Suppressive activity is attributable to the macrophage-derived cytokines interleukin 1 and tumor necrosis factor. Thus, these observations describe a role for defined cytokines in regulating the hormonal responsiveness and function of contractile cells. The effects of interleukin 1 and tumor necrosis factor on intracellular cAMP accumulation may be a model for immune modulation of other cellular functions dependent upon cyclic nucleotide metabolism. The uncoupling of agonist-occupied receptors from adenyl cyclase suggests that β -receptor or guanine nucleotide binding protein function is altered by the direct or indirect action of cytokines on cardiac muscle cells.

The Wheat Ethylene Response Factor Transcription Factor PATHOGEN-INDUCED ERF1 Mediates Host Responses to Both the Necrotrophic Pathogen Rhizoctonia cerealis and Freezing Stresses1[C][W][OPEN

PubMed Central

Zhu, Xiuliang; Qi, Lin; Liu, Xin; Cai, Shibin; Xu, Huijun; Huang, Rongfeng; Li, Jiarui; Wei, Xuening; Zhang, Zengyan

2014-01-01

Sharp eyespot disease (primarily caused by the pathogen Rhizoctonia cerealis) and freezing stress are important yield limitations for the production of wheat (Triticum aestivum). Here, we report new insights into the function and underlying mechanisms of an ethylene response factor (ERF) in wheat, Pathogen-Induced ERF1 (TaPIE1), in host responses to R. cerealis and freezing stresses. TaPIE1-overexpressing transgenic wheat exhibited significantly enhanced resistance to both R. cerealis and freezing stresses, whereas TaPIE1-underexpressing wheat plants were more susceptible to both stresses relative to control plants. Following both stress treatments, electrolyte leakage and hydrogen peroxide content were significantly reduced, and both proline and soluble sugar contents were elevated in TaPIE1-overexpressing wheat, whereas these physiological traits in TaPIE1-underexpressing wheat exhibited the opposite trend. Microarray and quantitative reverse transcription-polymerase chain reaction analyses of TaPIE1-overexpressing and -underexpressing wheat plants indicated that TaPIE1 activated a subset of defense- and stress-related genes. Assays of DNA binding by electrophoretic mobility shift and transient expression in tobacco (Nicotiana tabacum) showed that the GCC boxes in the promoters of TaPIE1-activated genes were essential for transactivation by TaPIE1. The transactivation activity of TaPIE1 and the expression of TaPIE1-activated defense- and stress-related genes were significantly elevated following R. cerealis, freezing, and exogenous ethylene treatments. TaPIE1-mediated responses to R. cerealis and freezing were positively modulated by ethylene biosynthesis. These data suggest that TaPIE1 positively regulates the defense responses to R. cerealis and freezing stresses by activating defense- and stress-related genes downstream of the ethylene signaling pathway and by modulating related physiological traits in wheat. PMID:24424323

Recombinant neutral endopeptidase attenuates substance P-induced plasma extravasation in the guinea pig skin.

PubMed

Rubinstein, I; Iwamoto, I; Ueki, I F; Borson, D B; Nadel, J A

1990-01-01

To determine whether exogenously administered neutral endopeptidase (NEP; enkephalinase, EC 3.4.24.11) inhibits the substance P-induced increase in vascular permeability in the skin, we examined the effects of recombinant human NEP on plasma extravasation induced by intradermal injection of substance P in guinea pig skin. Injection of substance P (2.5 X 10(-8) M) induced significant plasma extravasation in the skin (53 +/- 4 mm2 of Evans blue extravasation; mean +/- 1 SEM). In vitro incubation of substance P with recombinant human NEP prior to injection prevented the substance P-induced plasma extravasation in the skin in a dose-dependent fashion. Intradermal preinjection of recombinant human NEP partially inhibited plasma extravasation induced by subsequent injection of substance P (52 +/- 9% of the control without NEP). The H1 and H2 histamine antagonists pyrilamine and cimetidine, and a muscarinic antagonist, atropine, had no effects on substance P-induced responses. Two products of substance P degradation by NEP containing the carboxy-terminal portion, substance P7-11 and substance P8-11, were also without effect. These findings suggest that recombinant human NEP can attenuate substance P-induced increases in vascular permeability in guinea pig skin and, therefore, may be useful in treating dermatologic disorders in which abnormal responses to substance P or other neuropeptides cleaved by NEP may occur.

The National Educational Panel Study (NEPS) in Germany: An Overview of Design, Research Options and Access, with a Focus on Lower-Secondary School

ERIC Educational Resources Information Center

Strietholt, Rolf; Naujokat, Kerstin; Mai, Tobias; Kretschmer, Sara; Jarsinski, Stephan; Goy, Martin; Frahm, Sarah; Kanders, Michael; Bos, Wilfried; Blatt, Inge

2013-01-01

This article introduces the National Educational Panel Study (NEPS). This German longitudinal study produces a vast amount of data for the scientific community, and researchers all around Europe are invited to use the data to address various research questions empirically. Therefore, the authors provide information about the purpose as well as the…

A novel transcription factor gene FHS1 is involved in the DNA damage response in Fusarium graminearum

PubMed Central

Son, Hokyoung; Fu, Minmin; Lee, Yoonji; Lim, Jae Yun; Min, Kyunghun; Kim, Jin-Cheol; Choi, Gyung Ja; Lee, Yin-Won

2016-01-01

Cell cycle regulation and the maintenance of genome integrity are crucial for the development and virulence of the pathogenic plant fungus Fusarium graminearum. To identify transcription factors (TFs) related to these processes, four DNA-damaging agents were applied to screen a F. graminearum TF mutant library. Sixteen TFs were identified to be likely involved in DNA damage responses. Fhs1 is a fungal specific Zn(II)2Cys6 TF that localises exclusively to nuclei. fhs1 deletion mutants were hypersensitive to hydroxyurea and defective in mitotic cell division. Moreover, deletion of FHS1 resulted in defects in perithecia production and virulence and led to the accumulation of DNA damage. Our genetic evidence demonstrated that the FHS1-associated signalling pathway for DNA damage response is independent of the ATM or ATR pathways. This study identified sixteen genes involved in the DNA damage response and is the first to characterise the novel transcription factor gene FHS1, which is involved in the DNA damage response. The results provide new insights into mechanisms underlying DNA damage responses in fungi, including F. graminearum. PMID:26888604

Effects of epithelium removal on relaxation of airway smooth muscle induced by vasoactive intestinal peptide and electrical field stimulation.

PubMed Central

Farmer, S. G.; Togo, J.

1990-01-01

1. We have studied the effect of epithelium removal on relaxation of guinea-pig isolated tracheal smooth muscle induced by vasoactive intestinal peptide (VIP) or stimulation of non-adrenergic, non-cholinergic (NANC) inhibitory nerves. Also examined were the effects of inhibitors of neutral endopeptidase (NEP) and angiotensin-converting enzyme (ACE). 2. Epithelium removal produced a 3.6 +/- 0.4 fold leftward shift in the VIP concentration-response curve. The supersensitivity to VIP, following epithelium removal was abolished by phosphoramidon or thiorphan (NEP inhibitors), but unaffected by captopril (an ACE inhibitor). In intact trachea, the NEP inhibitors produced leftward shifts in the VIP curves similar to those produced by epithelium removal. 3. In contrast to responses to exogenous VIP, neurogenic NANC inhibitory responses to electrical field stimulation were affected neither by epithelial denudation nor by the peptidase inhibitors. 4. As in previous studies, epithelium removal increased tracheal sensitivity to isoprenaline. This was not altered by pretreatment with a cocktail of peptidase inhibitors. Thus, the effect of the NEP inhibitors on responses to VIP appears to be relatively specific. 5. These data indicate that exogenous VIP is a substrate for airway NEP, since inhibition of the enzyme potentiates the peptide. This is further evidence that the airway epithelium provides a source for the metabolism of mediators. 6. In guinea-pig trachea the NEP responsible for cleaving VIP may be located largely in the epithelial layer, since NEP inhibition was without effect on sensitivity to VIP in epithelium-denuded preparations. If VIP is a NANC inhibitory neurotransmitter in this tissue its degradation endogenously does not appear to involve epithelial NEP. PMID:2196967

High Power Electric Propulsion System for NEP: Propulsion and Trajectory Options

DOE Office of Scientific and Technical Information (OSTI.GOV)

Koppel, Christophe R.; Duchemin, Olivier; Valentian, Dominique

Recent US initiatives in Nuclear Propulsion lend themselves naturally to raising the question of the assessment of various options and particularly to propose the High Power Electric Propulsion Subsystem (HPEPS) for the Nuclear Electric Propulsion (NEP). The purpose of this paper is to present the guidelines for the HPEPS with respect to the mission to Mars, for automatic probes as well as for manned missions. Among the various options, the technological options and the trajectory options are pointed out. The consequences of the increase of the electrical power of a thruster are first an increase of the thrust itself, butmore » also, as a general rule, an increase of the thruster performance due to its higher efficiency, particularly its specific impulse increase. The drawback is as a first parameter, the increase of the thruster's size, hence the so-called 'thrust density' shall be high enough or shall be drastically increased for ions thrusters. Due to the large mass of gas needed to perform the foreseen missions, the classical xenon rare gas is no more in competition, the total world production being limited to 20 -40 tons per year. Thus, the right selection of the propellant feeding the thruster is of prime importance. When choosing a propellant with lower molecular mass, the consequences at thruster level are an increase once more of the specific impulse, but at system level the dead mass may increase too, mainly because the increase of the mass of the propellant system tanks. Other alternatives, in rupture with respect to the current technologies, are presented in order to make the whole system more attractive. The paper presents a discussion on the thruster specific impulse increase that is sometime considered an increase of the main system performances parameter, but that induces for all electric propulsion systems drawbacks in the system power and mass design that are proportional to the thruster specific power increase (kW/N). The electric thruster

Nuclear electric propulsion mission engineering study. Volume 1: Executive summary

NASA Technical Reports Server (NTRS)

1973-01-01

Results of a mission engineering analysis of nuclear-thermionic electric propulsion spacecraft for unmanned interplanetary and geocentric missions are summarized. Critical technologies associated with the development of nuclear electric propulsion (NEP) are assessed. Outer planet and comet rendezvous mission analysis, NEP stage design for geocentric and interplanetary missions, NEP system development cost and unit costs, and technology requirements for NEP stage development are studied. The NEP stage design provides both inherent reliability and high payload mass capability. The NEP stage and payload integration was found to be compatible with the space shuttle.

Role of interferon regulatory factor-1 in lipopolysaccharide-induced mitochondrial damage and oxidative stress responses in macrophages

PubMed Central

Deng, Song-Yun; Zhang, Le-Meng; Ai, Yu-hang; Pan, Pin-Hua; Zhao, Shuang-Ping; Su, Xiao-Li; Wu, Dong-Dong; Tan, Hong-Yi; Zhang, Li-Na; Tsung, Allan

2017-01-01

Sepsis causes many early deaths; both macrophage mitochondrial damage and oxidative stress responses are key factors in its pathogenesis. Although the exact mechanisms responsible for sepsis-induced mitochondrial damage are unknown, the nuclear transcription factor, interferon regulatory factor-1 (IRF-1) has been reported to cause mitochondrial damage in several diseases. Previously, we reported that in addition to promoting systemic inflammation, IRF-1 promoted the apoptosis of and inhibited autophagy in macrophages. In the present study, we hypothesized that lipopolysaccharide (LPS)-induced IRF-1 activation in macrophages may promote mitochondrial damage and oxidative stress. In vitro, LPS was found to promote IRF-1 activation, reactive oxygen species (ROS) production, adenosine triphosphate (ATP) depletion, superoxide dismutase (SOD) consumption, malondialdehyde (MDA) accumulation and mitochondrial depolarization in macrophages in a time- and dose-dependent manner. These effects were abrogated in cells in which IRF-1 was knocked down. Furthermore, IRF-1 overexpression increased LPS-induced oxidative stress responses and mitochondrial damage. In vivo, peritoneal macrophages obtained from IRF-1 knockout (KO) mice produced less ROS and had less mitochondrial depolarization and damage following the administration of LPS, when compared to their wild-type (WT) counterparts. In addition, IRF-1 KO mice exhibited a decreased release of mitochondrial DNA (mtDNA) following the administration of LPS. Thus, IRF-1 may be a critical factor in augmenting LPS-induced oxidative stress and mitochondrial damage in macrophages. PMID:28849179

Bean Metal-Responsive Element-Binding Transcription Factor Confers Cadmium Resistance in Tobacco1

PubMed Central

Sun, Na; Liu, Meng; Zhang, Wentao; Yang, Wanning; Bei, Xiujuan; Ma, Hui; Qiao, Fan; Qi, Xiaoting

2015-01-01

Cadmium (Cd) is highly toxic to plants. Modulation of Cd-responsive transcription is an important way for Cd detoxification in plants. Metal-responsive element (MRE) is originally described in animal metallothionein genes. Although functional MREs also exist in Cd-regulated plant genes, specific transcription factors that bind MRE to regulate Cd tolerance have not been identified. Previously, we showed that Cd-inducible bean (Phaseolus vulgaris) stress-related gene2 (PvSR2) produces a short (S) PvSR2 transcript (S-PvSR2) driven by an intronic promoter. Here, we demonstrate that S-PvSR2 encodes a bean MRE-binding transcription factor1 (PvMTF-1) that confers Cd tolerance in tobacco (Nicotiana tabacum). PvMTF-1 expression was up-regulated by Cd at the levels of RNA and protein. Importantly, expression of PvMTF-1 in tobacco enhanced Cd tolerance, indicating its role in regulating Cd resistance in planta. This was achieved through direct regulation of a feedback-insensitive Anthranilate Synthase α-2 chain gene (ASA2), which catalyzes the first step for tryptophan biosynthesis. In vitro and in vivo DNA-protein interaction studies further revealed that PvMTF-1 directly binds to the MRE in the ASA2 promoter, and this binding depends on the zinc finger-like motif of PvMTF-1. Through modulating ASA2 up-regulation by Cd, PvMTF-1 increased free tryptophan level and subsequently reduced Cd accumulation, thereby enhancing Cd tolerance of transgenic tobacco plants. Consistent with this observation, tobacco transiently overexpressing ASA2 also exhibited increased tolerance to Cd. We conclude that PvMTF-1 is a zinc finger-like transcription factor that links MRE to Cd resistance in transgenic tobacco through activation of tryptophan biosynthesis. PMID:25624396

Ethylene Response Factor TERF1, Regulated by ETHYLENE-INSENSITIVE3-like Factors, Functions in Reactive Oxygen Species (ROS) Scavenging in Tobacco (Nicotiana tabacum L.).

PubMed

Zhang, Hongbo; Li, Ang; Zhang, Zhijin; Huang, Zejun; Lu, Pingli; Zhang, Dingyu; Liu, Xinmin; Zhang, Zhong-Feng; Huang, Rongfeng

2016-07-20

The phytohormone ethylene plays a crucial role in the production and accumulation of reactive oxygen species (ROS) in plants under stress conditions. Ethylene response factors (ERFs) are important ethylene-signaling regulators functioning in plant defense responses against biotic and abiotic stresses. However, the roles of ERFs during plant adapting to ROS stress have not yet been well documented. Our studies previously reported that a tomato ERF transcription factor TERF1 functions in the regulation of plant ethylene responses and stress tolerance. Here, we report our findings regarding the roles of TERF1 in ROS scavenging. In this study, we revealed that the transcription of TERF1 is regulated by upstream EIN3-like (EIN3, ethylene-insensitive 3) regulators LeEIL3 and LeEIL4 in tomato (Solanum lycopersicum), and is also inducible by exogenous applied ROS-generating reagents. Ectopic expression of TERF1 in tobacco promoted the expression of genes involved in oxidative stress responses, including carbonic anhydrase functioning in hypersensitive defense, catalase and glutathione peroxidase catalyzing oxidative reactions, and GDP-D-mannose pyrophosphorylase functioning in ascorbic acid biosynthesis, reduced the ROS content induced by ethylene treatment, and enhanced stress tolerance of tobacco seedlings to hydrogen peroxide (H2O2). Cumulatively, these findings suggest that TERF1 is an ethylene inducible factor regulating ROS scavenging during stress responses.

Estimation of Gust Response Factor for a Tall Building Model with 1:1.5 Plan Ratios

NASA Astrophysics Data System (ADS)

Sarath Kumar, H.; Selvi Rajan, S.

2017-08-01

The purpose of structural analysis and design of structures as per the building codes and its corresponding standers is to ensure the safety of structure under maximum loads and remains functional under service load. The structure which is designed under consideration of codes should also satisfy the durability, economy and aesthetics. The primary purpose of this work is to understand and compare design wind loads according with the Gust Response Factor as per codes of practices. The paper is concerned with the calculation of design wind loads on a rectangular building model (1:300gemetric scale) of size 10cm x 15cm x 70cm with an aspect ratio of 1:1.5:7 at eight different levels over the height under sub-urban terrain category for 00 angle and 900 angle wind incidence. The experiment id conducted in an atmospheric boundary layer wind tunnel facility of CSIR-Structural engineering Research centre, Chennai. The measured pressures are integrated to evaluate mean and RMS (Root, Mean, Square). Further the variation of above mentioned loads and response factor along the heights of the building with respect to sub-urban terrain condition are discussed and summarized in addition, the codal values of various international standards [IS-875 part-3 1987, IS-875 part-3 draft, ASCE-07] have also considered for comparison.

Role of Neprilysin in Airway Inflammation Induced by Diesel Exhaust Emissions

PubMed Central

Wong, Simon S.; Sun, Nina N.; Fastje, Cynthia D.; Witten, Mark L.; Lantz, R. Clark; Lu, Bao; Sherrill, Duane L.; Gerard, Craig J.; Burgess, Jefferey L.

2016-01-01

In this study, we examined the role of neprilysin (NEP*), a key membrane-bound endopeptidase, in the inflammatory response induced by diesel exhaust emissions (DEE) in the airways through a number of approaches: in vitro, animal, and controlled human exposure. Our specific aims were (1) to examine the role of NEP in inflammatory injury induced by diesel exhaust particles (DEP) using Nep-intact (wild-type) and Nep-null mice; (2) to examine which components of DEP are associated with NEP downregulation in vitro; (3) to determine the molecular impact of DEP exposure and decreased NEP expression on airway epithelial cells’ gene expression in vitro, using a combination of RNA interference (RNAi) and microarray approaches; and (4) to evaluate the effects on NEP activity of human exposure to DEE. We report four main results: First, we found that exposure of normal mice to DEP consisting of standard reference material (SRM) 2975 via intratracheal installation can downregulate NEP expression in a concentration-dependent manner. The changes were accompanied by increases in the number of macrophages and epithelial cells, as well as proinflammatory cytokines, examined in bronchoalveolar lavage (BAL) fluid and cells. Nep-null mice displayed increased and/or additional inflammatory responses when compared with wild-type mice, especially in response to exposure to the higher dose of DEP that we used. These in vivo findings suggest that loss of NEP in mice could cause increased susceptibility to injury or exacerbate inflammatory responses after DEP exposure via release of specific cytokines from the lungs. Second, we found evidence, using in vitro studies, that downregulation of NEP by DEP in cultured human epithelial BEAS-2B cells was mostly attributable to DEP-adsorbed organic compounds, whereas the carbonaceous core and transition metal components of DEP had little or no effect on NEP messenger RNA (mRNA) expression. This NEP downregulation was not a specific response to DEP

The RNA Polymerase-Associated Factor 1 Complex Is Required for Plant Touch Responses

PubMed Central

Jensen, Gregory S.; Fal, Kateryna; Hamant, Olivier

2017-01-01

Abstract Thigmomorphogenesis is a stereotypical developmental alteration in the plant body plan that can be induced by repeatedly touching plant organs. To unravel how plants sense and record multiple touch stimuli we performed a novel forward genetic screen based on the development of a shorter stem in response to repetitive touch. The touch insensitive (ths1) mutant identified in this screen is defective in some aspects of shoot and root thigmomorphogenesis. The ths1 mutant is an intermediate loss-of-function allele of VERNALIZATION INDEPENDENCE 3 (VIP3), a previously characterized gene whose product is part of the RNA polymerase II-associated factor 1 (Paf1) complex. The Paf1 complex is found in yeast, plants and animals, and has been implicated in histone modification and RNA processing. Several components of the Paf1 complex are required for reduced stem height in response to touch and normal root slanting and coiling responses. Global levels of histone H3K36 trimethylation are reduced in VIP3 mutants. In addition, THS1/VIP3 is required for wild type histone H3K36 trimethylation at the TOUCH3 (TCH3) and TOUCH4 (TCH4) loci and for rapid touch-induced upregulation of TCH3 and TCH4 transcripts. Thus, an evolutionarily conserved chromatin-modifying complex is required for both short- and long-term responses to mechanical stimulation, providing insight into how plants record mechanical signals for thigmomorphogenesis. PMID:28204553

The wheat ethylene response factor transcription factor pathogen-induced ERF1 mediates host responses to both the necrotrophic pathogen Rhizoctonia cerealis and freezing stresses.

PubMed

Zhu, Xiuliang; Qi, Lin; Liu, Xin; Cai, Shibin; Xu, Huijun; Huang, Rongfeng; Li, Jiarui; Wei, Xuening; Zhang, Zengyan

2014-03-01

Sharp eyespot disease (primarily caused by the pathogen Rhizoctonia cerealis) and freezing stress are important yield limitations for the production of wheat (Triticum aestivum). Here, we report new insights into the function and underlying mechanisms of an ethylene response factor (ERF) in wheat, Pathogen-Induced ERF1 (TaPIE1), in host responses to R. cerealis and freezing stresses. TaPIE1-overexpressing transgenic wheat exhibited significantly enhanced resistance to both R. cerealis and freezing stresses, whereas TaPIE1-underexpressing wheat plants were more susceptible to both stresses relative to control plants. Following both stress treatments, electrolyte leakage and hydrogen peroxide content were significantly reduced, and both proline and soluble sugar contents were elevated in TaPIE1-overexpressing wheat, whereas these physiological traits in TaPIE1-underexpressing wheat exhibited the opposite trend. Microarray and quantitative reverse transcription-polymerase chain reaction analyses of TaPIE1-overexpressing and -underexpressing wheat plants indicated that TaPIE1 activated a subset of defense- and stress-related genes. Assays of DNA binding by electrophoretic mobility shift and transient expression in tobacco (Nicotiana tabacum) showed that the GCC boxes in the promoters of TaPIE1-activated genes were essential for transactivation by TaPIE1. The transactivation activity of TaPIE1 and the expression of TaPIE1-activated defense- and stress-related genes were significantly elevated following R. cerealis, freezing, and exogenous ethylene treatments. TaPIE1-mediated responses to R. cerealis and freezing were positively modulated by ethylene biosynthesis. These data suggest that TaPIE1 positively regulates the defense responses to R. cerealis and freezing stresses by activating defense- and stress-related genes downstream of the ethylene signaling pathway and by modulating related physiological traits in wheat.

Structural studies of a bifunctional inhibitor of neprilysin and DPP-IV.

PubMed

Oefner, Christian; Pierau, Sabine; Schulz, Henk; Dale, Glenn E

2007-09-01

Neutral endopeptidase (NEP) is the major enzyme involved in the metabolic inactivation of a number of bioactive peptides including the enkephalins, substance P, endothelin, bradykinin and atrial natriuretic factor, as well as the incretin hormone glucagon-like peptide 1 (GLP-1), which is a potent stimulator of insulin secretion. The activity of GLP-1 is also rapidly abolished by the serine protease dipeptidyl peptidase IV (DPP-IV), which led to an elevated interest in inhibitors of this enzyme for the treatment of type II diabetes. A dual NEP/DPP-IV inhibitor concept is proposed, offering an alternative strategy for the treatment of type 2 diabetes. Here, the synthesis and crystal structures of the soluble extracellular domain of human NEP (residues 52-749) complexed with the NEP, competitive and potent dual NEP/DPP-IV inhibitor MCB3937 are described.

Lysosomal Protein Lamtor1 Controls Innate Immune Responses via Nuclear Translocation of Transcription Factor EB.

PubMed

Hayama, Yoshitomo; Kimura, Tetsuya; Takeda, Yoshito; Nada, Shigeyuki; Koyama, Shohei; Takamatsu, Hyota; Kang, Sujin; Ito, Daisuke; Maeda, Yohei; Nishide, Masayuki; Nojima, Satoshi; Sarashina-Kida, Hana; Hosokawa, Takashi; Kinehara, Yuhei; Kato, Yasuhiro; Nakatani, Takeshi; Nakanishi, Yoshimitsu; Tsuda, Takeshi; Koba, Taro; Okada, Masato; Kumanogoh, Atsushi

2018-06-01

Amino acid metabolism plays important roles in innate immune cells, including macrophages. Recently, we reported that a lysosomal adaptor protein, Lamtor1, which serves as the scaffold for amino acid-activated mechanistic target of rapamycin complex 1 (mTORC1), is critical for the polarization of M2 macrophages. However, little is known about how Lamtor1 affects the inflammatory responses that are triggered by the stimuli for TLRs. In this article, we show that Lamtor1 controls innate immune responses by regulating the phosphorylation and nuclear translocation of transcription factor EB (TFEB), which has been known as the master regulator for lysosome and autophagosome biogenesis. Furthermore, we show that nuclear translocation of TFEB occurs in alveolar macrophages of myeloid-specific Lamtor1 conditional knockout mice and that these mice are hypersensitive to intratracheal administration of LPS and bleomycin. Our observation clarified that the amino acid-sensing pathway consisting of Lamtor1, mTORC1, and TFEB is involved in the regulation of innate immune responses. Copyright © 2018 by The American Association of Immunologists, Inc.

Involvement of neutral endopeptidase in neoplastic progression.

PubMed

Sumitomo, Makoto; Shen, Ruoqian; Nanus, David M

2005-08-01

Neutral endopeptidase 24.11 (NEP) is a 90-110 kDa cell surface cell surface peptidase that is normally expressed by numerous tissues, including prostate, kidney, intestine, endometrium, adrenal glands and lung. This enzyme cleaves peptide bonds on the amino side of hydrophobic amino acids and inactivates a variety of physiologically active peptides, including atrial natriuretic factor, substance P, bradykinin, oxytocin, Leu- and Met-enkephalins, neurotensin, bombesin, endothelin-1, and bombesin-like peptides. NEP reduces the local concentration of peptide available for receptor binding and signal transduction. Loss or decreases in NEP expression have been reported in a variety of malignancies. Reduced NEP may promote peptide-mediated proliferation by allowing accumulation of higher peptide concentrations at the cell surface, and facilitate the development or progression of neoplasia. We have used prostate cancer as model in which to study the involvement of NEP in malignancy. Using a variety of experimental approaches, including recombinant NEP, cell lines expressing wild-type and mutant NEP protein, and cell lines expressing NEP protein with a mutated cytoplasmic domain, we have examined the effects of NEP on cell migration and cell survival. We have shown that the effects of NEP are mediated by its ability to catalytically inactivate substrates such as bombesin and endothelin-1, but also through direct protein-protein interaction with other protein such as Lyn kinase [which associates with the p85 subunit of phosphatidylinositol 3-kinase (PI3-K) resulting in NEP-Lyn-PI3-K protein complex], ezrin/radixin/moesin (ERM) proteins, and the PTEN tumor suppressor protein. We review the mechanisms of NEP's tumor suppressive action and how NEP loss contributes to tumor progression.

Innate immune humoral factors, C1q and factor H, with differential pattern recognition properties, alter macrophage response to carbon nanotubes.

PubMed

Pondman, Kirsten M; Pednekar, Lina; Paudyal, Basudev; Tsolaki, Anthony G; Kouser, Lubna; Khan, Haseeb A; Shamji, Mohamed H; Ten Haken, Bennie; Stenbeck, Gudrun; Sim, Robert B; Kishore, Uday

2015-11-01

Interaction between the complement system and carbon nanotubes (CNTs) can modify their intended biomedical applications. Pristine and derivatised CNTs can activate complement primarily via the classical pathway which enhances uptake of CNTs and suppresses pro-inflammatory response by immune cells. Here, we report that the interaction of C1q, the classical pathway recognition molecule, with CNTs involves charge pattern and classical pathway activation that is partly inhibited by factor H, a complement regulator. C1q and its globular modules, but not factor H, enhanced uptake of CNTs by macrophages and modulated the pro-inflammatory immune response. Thus, soluble complement factors can interact differentially with CNTs and alter the immune response even without complement activation. Coating CNTs with recombinant C1q globular heads offers a novel way of controlling classical pathway activation in nanotherapeutics. Surprisingly, the globular heads also enhance clearance by phagocytes and down-regulate inflammation, suggesting unexpected complexity in receptor interaction. Carbon nanotubes (CNTs) maybe useful in the clinical setting as targeting drug carriers. However, it is also well known that they can interact and activate the complement system, which may have a negative impact on the applicability of CNTs. In this study, the authors functionalized multi-walled CNT (MWNT), and investigated the interaction with the complement pathway. These studies are important so as to gain further understanding of the underlying mechanism in preparation for future use of CNTs in the clinical setting. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

Comparison of the spatial distribution of endopeptidase-24.11 with substance P, substance P receptor (NK-1r) and gastric efferent neurons in the dorsal vagal complex of the rat.

PubMed

Ladic, L; Buchan, A

1997-01-24

The spatial location of neutral endopeptidase 24.11 (NEP) immunoreactivity was compared to that of substance P (SP), SP receptor (NK-1r) and identified gastric efferent neurons in the dorsal vagal complex in rat brainstem. The majority of NEP labeling was observed caudal to the obex. Neutral endopeptidase-immunoreactivity was associated with the central canal, ependyma and blood vessels, and surrounded the area postrema. A comparison of the results of immunocytochemical and retrograde tracing experiments demonstrated the absence of co-labeling of neurons or their process with NEP and either substance P or NK-1r. Furthermore, no NEP-immunoreactivity was observed in the vicinity of identified gastric efferents in the dorsal motor nucleus of the vagus. These results would suggest that NEP does not degrade SP in the vicinity of gastric efferent neurons.

Ultra-Sensitive Transition-Edge Sensors for the Background Limited Infrared/Sub-mm Spectrograph (BLISS)

NASA Technical Reports Server (NTRS)

Beyer, A. D.; Kenyon, M. E.; Echternach, P. M.; Chui, T.; Eom, B.-H.; Day, P. K.; Bock, J. J.; Holmes, W.A.; Bradford, C. M.

2011-01-01

We report progress in fabricating ultra-sensitive superconducting transition-edge sensors (TESs) for BLISS. BLISS is a suite of grating spectrometers covering 35-433 micron with R approx. 700 cooled to 50 mK that is proposed to fly on the Japanese space telescope SPICA. The detector arrays for BLISS are TES bolometers readout with a time domain SQUID multiplexer. The required noise equivalent power (NEP) for BLISS is NEP = 10(exp -19) W/Hz(exp 1/2) with an ultimate goal of NEP= 5 x 10(exp -20) W/Hz(exp 1/2) to achieve background limited noise performance. The required and goal response times are tau = 150 ms and tau = 50ms respectively to achieve the NEP at the required and goal optical chop frequency 1-5 Hz. We measured prototype BLISS arrays and have achieved NEP = 6 x 10(exp -18) W/Hz(exp 1/2) and tau = 1.4 ms with a Ti TES (T(sub C) = 565 mK) and NEP approx. 2.5 x 10(exp -19) W/Hz(exp 1/2) and tau approximates 4.5 ms with an Ir TES (T(sub C) = 130 mK). Dark power for these tests is estimated at 1-5 fW.

The Role of Candida albicans Transcription Factor RLM1 in Response to Carbon Adaptation.

PubMed

Oliveira-Pacheco, João; Alves, Rosana; Costa-Barbosa, Augusto; Cerqueira-Rodrigues, Bruno; Pereira-Silva, Patricia; Paiva, Sandra; Silva, Sónia; Henriques, Mariana; Pais, Célia; Sampaio, Paula

2018-01-01

Candida albicans is the main causative agent of candidiasis and one of the most frequent causes of nosocomial infections worldwide. In order to establish an infection, this pathogen supports effective stress responses to counter host defenses and adapts to changes in the availability of important nutrients, such as alternative carbon sources. These stress responses have clear implications on the composition and structure of Candida cell wall. Therefore, we studied the impact of lactate, a physiologically relevant carbon source, on the activity of C. albicans RLM1 transcriptional factor. RLM1 is involved in the cell wall integrity pathway and plays an important role in regulating the flow of carbohydrates into cell wall biosynthesis pathways. The role of C. albicans RLM1 in response to lactate adaptation was assessed in respect to several virulence factors, such as the ability to grow under cell wall damaging agents, filament, adhere or form biofilm, as well as to immune recognition. The data showed that growth of C. albicans cells in the presence of lactate induces the secretion of tartaric acid, which has the potential to modulate the TCA cycle on both the yeast and the host cells. In addition, we found that adaptation of C. albicans cells to lactate reduces their internalization by immune cells and consequent % of killing, which could be correlated with a lower exposure of the cell wall β-glucans. In addition, absence of RLM1 has a minor impact on internalization, compared with the wild-type and complemented strains, but it reduces the higher efficiency of lactate grown cells at damaging phagocytic cells and induces a high amount of IL-10, rendering these cells more tolerable to the immune system. The data suggests that RLM1 mediates cell wall remodeling during carbon adaptation, impacting their interaction with immune cells.

Egr-1 and serum response factor are involved in growth factors- and serum-mediated induction of E2-EPF UCP expression that regulates the VHL-HIF pathway.

PubMed

Lim, Jung Hwa; Jung, Cho-Rok; Lee, Chan-Hee; Im, Dong-Soo

2008-11-01

E2-EPF ubiquitin carrier protein (UCP) has been shown to be highly expressed in common human cancers and target von Hippel-Lindau (VHL) for proteosomal degradation in cells, thereby stabilizing hypoxia-inducible factor (HIF)-1alpha. Here, we investigated cellular factors that regulate the expression of UCP gene. Promoter deletion assay identified binding sites for early growth response-1 (Egr-1) and serum response factor (SRF) in the UCP promoter. Hepatocyte or epidermal growth factor (EGF), or phorbol 12-myristate 13-acetate induced UCP expression following early induction of Egr-1 expression in HeLa cells. Serum increased mRNA and protein levels of SRF and UCP in the cell. By electrophoretic mobility shift and chromatin immunoprecipitation assays, sequence-specific DNA-binding of Egr-1 and SRF to the UCP promoter was detected in nuclear extracts from HeLa cells treated with EGF and serum, respectively. Overexpression of Egr-1 or SRF increased UCP expression. RNA interference-mediated depletion of endogenous Egr-1 or SRF impaired EGF- or serum-mediated induction of UCP expression, which was required for cancer cell proliferation. Systemic delivery of EGF into mice also increased UCP expression following early induction of Egr-1 expression in mouse liver. The induced UCP expression by the growth factors or serum increased HIF-1alpha protein level under non-hypoxic conditions, suggesting that the Egr-1/SRF-UCP-VHL pathway is in part responsible for the increased HIF-1alpha protein level in vitro and in vivo. Thus, growth factors and serum induce expression of Egr-1 and SRF, respectively, which in turn induces UCP expression that positively regulates cancer cell growth.

Regulation of the Candida albicans Cell Wall Damage Response by Transcription Factor Sko1 and PAS Kinase Psk1

PubMed Central

Rauceo, Jason M.; Blankenship, Jill R.; Fanning, Saranna; Hamaker, Jessica J.; Deneault, Jean-Sebastien; Smith, Frank J.; Nantel, Andre

2008-01-01

The environmental niche of each fungus places distinct functional demands on the cell wall. Hence cell wall regulatory pathways may be highly divergent. We have pursued this hypothesis through analysis of Candida albicans transcription factor mutants that are hypersensitive to caspofungin, an inhibitor of beta-1,3-glucan synthase. We report here that mutations in SKO1 cause this phenotype. C. albicans Sko1 undergoes Hog1-dependent phosphorylation after osmotic stress, like its Saccharomyces cerevisiae orthologues, thus arguing that this Hog1-Sko1 relationship is conserved. However, Sko1 has a distinct role in the response to cell wall inhibition because 1) sko1 mutants are much more sensitive to caspofungin than hog1 mutants; 2) Sko1 does not undergo detectable phosphorylation in response to caspofungin; 3) SKO1 transcript levels are induced by caspofungin in both wild-type and hog1 mutant strains; and 4) sko1 mutants are defective in expression of caspofungin-inducible genes that are not induced by osmotic stress. Upstream Sko1 regulators were identified from a panel of caspofungin-hypersensitive protein kinase–defective mutants. Our results show that protein kinase Psk1 is required for expression of SKO1 and of Sko1-dependent genes in response to caspofungin. Thus Psk1 and Sko1 lie in a newly described signal transduction pathway. PMID:18434592

Transcriptional regulation of the cytosolic chaperonin theta subunit gene, Cctq, by Ets domain transcription factors Elk-1, Sap-1a, and Net in the absence of serum response factor.

PubMed

Yamazaki, Yuji; Kubota, Hiroshi; Nozaki, Masami; Nagata, Kazuhiro

2003-08-15

The chaperonin-containing t-complex polypeptide 1 (CCT) is a molecular chaperone that facilitates protein folding in eukaryotic cytosol, and the expression of CCT is highly dependent on cell growth. We show here that transcription of the gene encoding the theta subunit of mouse CCT, Cctq, is regulated by the ternary complex factors (TCFs), Elk-1, Sap-1a, and Net (Sap-2). Reporter gene assay using HeLa cells indicated that the Cctq gene promoter contains a cis-acting element of the CCGGAAGT sequence (CQE1) at -36 bp. The major CQE1-binding proteins in HeLa cell nuclear extract was recognized by anti-Elk-1 or anti-Sap-1a antibodies in electrophoretic mobility shift assay, and recombinant Elk-1, Sap-1a, or Net specifically recognized CQE1. The CQE1-dependent transcriptional activity in HeLa cells was virtually abolished by overexpression of the DNA binding domains of TCFs. Overexpression of full-length TCFs with Ras indicated that exogenous TCFs can regulate the CQE1-dependent transcription in a Ras-dependent manner. PD98059, an inhibitor of MAPK, significantly repressed the CQE1-dependent transcription. However, no serum response factor was detected by electrophoretic mobility shift assay using the CQE1 element. These results indicate that transcription of the Cctq gene is regulated by TCFs under the control of the Ras/MAPK pathway, probably independently of serum response factor.

Genetic Variation for Thermotolerance in Lettuce Seed Germination Is Associated with Temperature-Sensitive Regulation of ETHYLENE RESPONSE FACTOR1 (ERF1)1[OPEN

PubMed Central

O’Brien, Laurel K.; Truco, Maria Jose; Huo, Heqiang; Sideman, Rebecca; Hayes, Ryan; Michelmore, Richard W.

2016-01-01

Seeds of most lettuce (Lactuca sativa) cultivars are susceptible to thermoinhibition, or failure to germinate at temperatures above approximately 28°C, creating problems for crop establishment in the field. Identifying genes controlling thermoinhibition would enable the development of cultivars lacking this trait and, therefore, being less sensitive to high temperatures during planting. Seeds of a primitive accession (PI251246) of lettuce exhibited high-temperature germination capacity up to 33°C. Screening a recombinant inbred line population developed from PI215246 and cv Salinas identified a major quantitative trait locus (Htg9.1) from PI251246 associated with the high-temperature germination phenotype. Further genetic analyses discovered a tight linkage of the Htg9.1 phenotype with a specific DNA marker (NM4182) located on a single genomic sequence scaffold. Expression analyses of the 44 genes encoded in this genomic region revealed that only a homolog of Arabidopsis (Arabidopsis thaliana) ETHYLENE RESPONSE FACTOR1 (termed LsERF1) was differentially expressed between PI251246 and cv Salinas seeds imbibed at high temperature (30°C). LsERF1 belongs to a large family of transcription factors associated with the ethylene-signaling pathway. Physiological assays of ethylene synthesis, response, and action in parental and near-isogenic Htg9.1 genotypes strongly implicate LsERF1 as the gene responsible for the Htg9.1 phenotype, consistent with the established role for ethylene in germination thermotolerance of Compositae seeds. Expression analyses of genes associated with the abscisic acid and gibberellin biosynthetic pathways and results of biosynthetic inhibitor and hormone response experiments also support the hypothesis that differential regulation of LsERF1 expression in PI251246 seeds elevates their upper temperature limit for germination through interactions among pathways regulated by these hormones. Our results support a model in which LsERF1 acts through

Interrelated Roles for the Aryl Hydrocarbon Receptor and Hypoxia Inducible Factor-1α in the Immune Response to Infection

PubMed Central

Wagage, Sagie; Hunter, Christopher A.

2015-01-01

Cells of the immune system utilize multiple mechanisms to respond to environmental signals and recent studies have demonstrated roles for two closely related proteins, the aryl hydrocarbon receptor (AHR) and hypoxia inducible factor-1α (HIF1α), in these processes. The AHR is a transcription factor that is activated by diverse ligands found in the diet and environmental pollution as well as by microbial and host-derived products. In contrast, HIF1α is a transcription factor that is active under low oxygen conditions and mediates cellular responses to hypoxia. These evolutionarily conserved proteins have roles in the interrelated processes of metabolism, tumorigenesis, and vascular development. Additionally, the AHR and HIF1α have multiple effects on innate and adaptive immunity. This article provides an overview of the biology of these transcription factors and reviews the effects of AHR and HIF1α signaling on immunity to infection. There are many parallels between these two pathways and their functions highlight the importance of AHR and HIF1α activity particularly at barrier surfaces in coordinating responses to pathogens.

Loss of transcription factor early growth response gene 1 results in impaired endochondral bone repair

PubMed Central

Reumann, Marie K.; Strachna, Olga; Yagerman, Sarah; Torrecilla, Daniel; Kim, Jihye; Doty, Steven B.; Lukashova, Lyudmila; Boskey, Adele L.; Mayer-Kuckuk, Philipp

2011-01-01

Transcription factors that play a role in ossification during development are expected to participate in postnatal fracture repair since the endochondral bone formation that occurs in embryos is recapitulated during fracture repair. However, inherent differences exist between bone development and fracture repair, including a sudden disruption of tissue integrity followed by an inflammatory response. This raises the possibility that repair-specific transcription factors participate in bone healing. Here, we assessed the consequence of loss of early growth response gene 1 (EGR-1) on endochondral bone healing because this transcription factor has been shown to modulate repair in vascularized tissues. Model fractures were created in ribs of wild type (wt) and EGR-1−/− mice. Differences in tissue morphology and composition between these two animal groups were followed over 28 post fracture days (PFDs). In wt mice, bone healing occurred in healing phases characteristic of endochondral bone repair. A similar healing sequence was observed in EGR-1−/− mice but was impaired by alterations. A persistent accumulation of fibrin between the disconnected bones was observed on PFD7 and remained pronounced in the callus on PFD14. Additionally, the PFD14 callus was abnormally enlarged and showed increased deposition of mineralized tissue. Cartilage ossification in the callus was associated with hyper-vascularity and -proliferation. Moreover, cell deposits located in proximity to the callus within skeletal muscle were detected on PFD14. Despite these impairments, repair in EGR-1−/− callus advanced on PFD28, suggesting EGR-1 is not essential for healing. Together, this study provides genetic evidence that EGR-1 is a pleiotropic regulator of endochondral fracture repair. PMID:21726677

Loss of transcription factor early growth response gene 1 results in impaired endochondral bone repair.

PubMed

Reumann, Marie K; Strachna, Olga; Yagerman, Sarah; Torrecilla, Daniel; Kim, Jihye; Doty, Stephen B; Lukashova, Lyudmila; Boskey, Adele L; Mayer-Kuckuk, Philipp

2011-10-01

Transcription factors that play a role in ossification during development are expected to participate in postnatal fracture repair since the endochondral bone formation that occurs in embryos is recapitulated during fracture repair. However, inherent differences exist between bone development and fracture repair, including a sudden disruption of tissue integrity followed by an inflammatory response. This raises the possibility that repair-specific transcription factors participate in bone healing. Here, we assessed the consequence of loss of early growth response gene 1 (EGR-1) on endochondral bone healing because this transcription factor has been shown to modulate repair in vascularized tissues. Model fractures were created in ribs of wild type (wt) and EGR-1(-/-) mice. Differences in tissue morphology and composition between these two animal groups were followed over 28 post fracture days (PFDs). In wt mice, bone healing occurred in healing phases characteristic of endochondral bone repair. A similar healing sequence was observed in EGR-1(-/-) mice but was impaired by alterations. A persistent accumulation of fibrin between the disconnected bones was observed on PFD7 and remained pronounced in the callus on PFD14. Additionally, the PFD14 callus was abnormally enlarged and showed increased deposition of mineralized tissue. Cartilage ossification in the callus was associated with hyper-vascularity and -proliferation. Moreover, cell deposits located in proximity to the callus within skeletal muscle were detected on PFD14. Despite these impairments, repair in EGR-1(-/-) callus advanced on PFD28, suggesting EGR-1 is not essential for healing. Together, this study provides genetic evidence that EGR-1 is a pleiotropic regulator of endochondral fracture repair. Copyright © 2011 Elsevier Inc. All rights reserved.

Basic Helix-Loop-Helix Transcription Factors JASMONATE-ASSOCIATED MYC2-LIKE1 (JAM1), JAM2, and JAM3 Are Negative Regulators of Jasmonate Responses in Arabidopsis1[W][OPEN

PubMed Central

Sasaki-Sekimoto, Yuko; Jikumaru, Yusuke; Obayashi, Takeshi; Saito, Hikaru; Masuda, Shinji; Kamiya, Yuji; Ohta, Hiroyuki; Shirasu, Ken

2013-01-01

Jasmonates regulate transcriptional reprogramming during growth, development, and defense responses. Jasmonoyl-isoleucine, an amino acid conjugate of jasmonic acid (JA), is perceived by the protein complex composed of the F-box protein CORONATINE INSENSITIVE1 (COI1) and JASMONATE ZIM DOMAIN (JAZ) proteins, leading to the ubiquitin-dependent degradation of JAZ proteins. This activates basic helix-loop-helix-type MYC transcription factors to regulate JA-responsive genes. Here, we show that the expression of genes encoding other basic helix-loop-helix transcription factors, JASMONATE ASSOCIATED MYC2-LIKE1 (JAM1), JAM2, and JAM3, is positively regulated in a COI1- and MYC2-dependent manner in Arabidopsis (Arabidopsis thaliana). However, contrary to myc2, the jam1jam2jam3 triple mutant exhibited shorter roots when treated with methyl jasmonate (MJ), indicating enhanced responsiveness to JA. Our genome-wide expression analyses revealed that key jasmonate metabolic genes as well as a set of genes encoding transcription factors that regulate the JA-responsive metabolic genes are negatively regulated by JAMs after MJ treatment. Consistently, loss of JAM genes resulted in higher accumulation of anthocyanin in MJ-treated plants as well as higher accumulation of JA and 12-hydroxyjasmonic acid in wounded plants. These results show that JAMs negatively regulate the JA responses in a manner that is mostly antagonistic to MYC2. PMID:23852442

The Potyviral P3 Protein Targets Eukaryotic Elongation Factor 1A to Promote the Unfolded Protein Response and Viral Pathogenesis1[OPEN

PubMed Central

Shine, M.B.; Cui, Xiaoyan; Chen, Xin; Ma, Na; Kachroo, Pradeep; Zhi, Haijan; Kachroo, Aardra

2016-01-01

The biochemical function of the potyviral P3 protein is not known, although it is known to regulate virus replication, movement, and pathogenesis. We show that P3, the putative virulence determinant of soybean mosaic virus (SMV), targets a component of the translation elongation complex in soybean. Eukaryotic elongation factor 1A (eEF1A), a well-known host factor in viral pathogenesis, is essential for SMV virulence and the associated unfolded protein response (UPR). Silencing GmEF1A inhibits accumulation of SMV and another ER-associated virus in soybean. Conversely, endoplasmic reticulum (ER) stress-inducing chemicals promote SMV accumulation in wild-type, but not GmEF1A-knockdown, plants. Knockdown of genes encoding the eEF1B isoform, which is important for eEF1A function in translation elongation, has similar effects on UPR and SMV resistance, suggesting a link to translation elongation. P3 and GmEF1A promote each other’s nuclear localization, similar to the nuclear-cytoplasmic transport of eEF1A by the Human immunodeficiency virus 1 Nef protein. Our results suggest that P3 targets host elongation factors resulting in UPR, which in turn facilitates SMV replication and place eEF1A upstream of BiP in the ER stress response during pathogen infection. PMID:27356973

Closed Brayton Cycle power system with a high temperature pellet bed reactor heat source for NEP applications

NASA Technical Reports Server (NTRS)

Juhasz, Albert J.; El-Genk, Mohamed S.; Harper, William B., Jr.

1992-01-01

Capitalizing on past and future development of high temperature gas reactor (HTGR) technology, a low mass 15 MWe closed gas turbine cycle power system using a pellet bed reactor heating helium working fluid is proposed for Nuclear Electric Propulsion (NEP) applications. Although the design of this directly coupled system architecture, comprising the reactor/power system/space radiator subsystems, is presented in conceptual form, sufficient detail is included to permit an assessment of overall system performance and mass. Furthermore, an attempt is made to show how tailoring of the main subsystem design characteristics can be utilized to achieve synergistic system level advantages that can lead to improved reliability and enhanced system life while reducing the number of parasitic load driven peripheral subsystems.

Neutral endopeptidase modulates substance P-induced activation of human neutrophils.

PubMed

Iwamoto, I; Kimura, A; Yamazaki, H; Nakagawa, N; Tomioka, H; Yoshida, S

1990-01-01

Neutral endopeptidase (NEP; EC 3.4.24.11) is well recognized as a regulatory peptidase for substance P (SP)-induced responses in various tissues. To determine whether NEP regulates SP-induced activation of human neutrophils, we examined the effect of the NEP inhibitor phosphoramidon on SP-induced superoxide generation and chemotaxis in human blood neutrophils. SP (10(-6)-10(-4) M) induced superoxide generation and chemotaxis in the neutrophils dose dependently. The NEP inhibitor enhanced the SP-induced responses. Thus, phosphoramidon (10(-6) M) shifted the dose-response curves of SP-induced superoxide generation and chemotaxis of the neutrophils to the left by 0.5-0.6 log. Phosphoramidon prevented the hydrolysis of SP by the neutrophils, the NEP activity of the neutrophils being assessed as 125 +/- 13 pmol of SP/min/10(6) cells. The N-terminal peptide SP (up to 3 x 10(-4) M), which was a major degrading product by NEP of the neutrophils, did not activate the neutrophils. We conclude that NEP modulates SP-induced activation of human neutrophils.

Aging and oxidative stress reduce the response of human articular chondrocytes to insulin-like growth factor 1 and osteogenic protein 1.

PubMed

Loeser, Richard F; Gandhi, Uma; Long, David L; Yin, Weihong; Chubinskaya, Susan

2014-08-01

To determine the effects of aging and oxidative stress on the response of human articular chondrocytes to insulin-like growth factor 1 (IGF-1) and osteogenic protein 1 (OP-1). Chondrocytes isolated from normal articular cartilage obtained from tissue donors were cultured in alginate beads or monolayer. Cells were stimulated with 50-100 ng/ml of IGF-1, OP-1, or both. Oxidative stress was induced using tert-butyl hydroperoxide. Sulfate incorporation was used to measure proteoglycan synthesis, and immunoblotting of cell lysates was performed to analyze cell signaling. Confocal microscopy was performed to measure nuclear translocation of Smad4. Chondrocytes isolated from the articular cartilage of tissue donors ranging in age from 24 years to 81 years demonstrated an age-related decline in proteoglycan synthesis stimulated by IGF-1 and IGF-1 plus OP-1. Induction of oxidative stress inhibited both IGF-1- and OP-1-stimulated proteoglycan synthesis. Signaling studies showed that oxidative stress inhibited IGF-1-stimulated Akt phosphorylation while increasing phosphorylation of ERK, and that these effects were greater in cells from older donors. Oxidative stress also increased p38 phosphorylation, which resulted in phosphorylation of Smad1 at the Ser(206) inhibitory site and reduced nuclear accumulation of Smad1. Oxidative stress also modestly reduced OP-1-stimulated nuclear translocation of Smad4. These results demonstrate an age-related reduction in the response of human chondrocytes to IGF-1 and OP-1, which are 2 important anabolic factors in cartilage, and suggest that oxidative stress may be a contributing factor by altering IGF-1 and OP-1 signaling. Copyright © 2014 by the American College of Rheumatology.

Antagonism of corticotropin-releasing factor CRF1 receptors blocks the enhanced response to cocaine after social stress.

PubMed

Ferrer-Pérez, Carmen; Reguilón, Marina D; Manzanedo, Carmen; Aguilar, M Asunción; Miñarro, José; Rodríguez-Arias, Marta

2018-03-15

Numerous studies have shown that social defeat stress induces an increase in the rewarding effects of cocaine. In this study we have investigated the role played by the main hypothalamic stress hormone, corticotropin-releasing factor (CRF), in the effects that repeated social defeat (RSD) induces in the conditioned rewarding effects and locomotor sensitization induced by cocaine. A total of 220 OF1 mice were divided into experimental groups according to the treatment received before each social defeat: saline, 5 or 10 mg/kg of the nonpeptidic corticotropin-releasing factor CRF 1 receptor antagonist CP-154,526, or 15 or 30 µg/kg of the peptidic corticotropin-releasing factor CRF 2 receptor antagonist Astressin 2 -B. Three weeks after the last defeat, conditioned place preference (CPP) induced by 1 mg/kg of cocaine was evaluated. Motor response to 10 mg/kg of cocaine was also studied after a sensitization induction. Blockade of corticotropin-releasing factor CRF 1 receptor reversed the increase in cocaine CPP induced by social defeat. Conversely, peripheral corticotropin-releasing factor CRF 2 receptor blockade produced similar effects to those observed in socially stressed animals. The effect of RSD on cocaine sensitization was again blocked by the corticotropin-releasing factor CRF 1 receptor antagonist, while peripheral CRF 2 receptor antagonist did not show effect. Acute administration of Astressin 2 -B induced an anxiogenic response. Our results confirm that CRF modulates the effects of social stress on reinforcement and sensitization induced by cocaine in contrasting ways. These findings highlight CRF receptors as potential therapeutic targets to be explored by research about stress-related addiction problems. Copyright © 2018 Elsevier B.V. All rights reserved.

Responses of ecosystem water use efficiency to spring snow and summer water addition with or without nitrogen addition in a temperate steppe

PubMed Central

Zhai, Penghui; Huang, Jianhui; Zhao, Xiang; Dong, Kuanhu

2018-01-01

Water use efficiency (WUE) is an important indicator of ecosystem functioning but how ecosystem WUE responds to climate change including precipitation and nitrogen (N) deposition increases is still unknown. To investigate such responses, an experiment with a randomized block design with water (spring snowfall or summer water addition) and nitrogen addition was conducted in a temperate steppe of northern China. We investigated net ecosystem CO2 production (NEP), gross ecosystem production (GEP) and evapotranspiration (ET) to calculate ecosystem WUE (WUEnep = NEP/ET or WUEgep = GEP/ET) under spring snow and summer water addition with or without N addition from 2011 to 2013. The results showed that spring snow addition only had significant effect on ecosystem WUE in 2013 and summer water addition showed positive effect on ecosystem WUE in 2011 and 2013, as their effects on NEP and GEP is stronger than ET. N addition increased ecosystem WUE in 2012 and 2013 both in spring snow addition and summer water addition for its increasing effects on NEP and GEP but no effect on ET. Summer water addition had less but N addition had greater increasing effects on ecosystem WUE as natural precipitation increase indicating that natural precipitation regulates ecosystem WUE responses to water and N addition. Moreover, WUE was tightly related with atmospheric vapor-pressure deficit (VPD), photosynthetic active radiation (PAR), precipitation and soil moisture indicating the regulation of climate drivers on ecosystem WUE. In addition, it also was affected by aboveground net primary production (ANPP). The study suggests that ecosystem WUE responses to water and N addition is determined by the change in carbon process rather than that in water process, which are regulated by climate change in the temperate steppe of northern China. PMID:29529082

Responses of ecosystem water use efficiency to spring snow and summer water addition with or without nitrogen addition in a temperate steppe.

PubMed

Zhang, Xiaolin; Zhai, Penghui; Huang, Jianhui; Zhao, Xiang; Dong, Kuanhu

2018-01-01

Water use efficiency (WUE) is an important indicator of ecosystem functioning but how ecosystem WUE responds to climate change including precipitation and nitrogen (N) deposition increases is still unknown. To investigate such responses, an experiment with a randomized block design with water (spring snowfall or summer water addition) and nitrogen addition was conducted in a temperate steppe of northern China. We investigated net ecosystem CO2 production (NEP), gross ecosystem production (GEP) and evapotranspiration (ET) to calculate ecosystem WUE (WUEnep = NEP/ET or WUEgep = GEP/ET) under spring snow and summer water addition with or without N addition from 2011 to 2013. The results showed that spring snow addition only had significant effect on ecosystem WUE in 2013 and summer water addition showed positive effect on ecosystem WUE in 2011 and 2013, as their effects on NEP and GEP is stronger than ET. N addition increased ecosystem WUE in 2012 and 2013 both in spring snow addition and summer water addition for its increasing effects on NEP and GEP but no effect on ET. Summer water addition had less but N addition had greater increasing effects on ecosystem WUE as natural precipitation increase indicating that natural precipitation regulates ecosystem WUE responses to water and N addition. Moreover, WUE was tightly related with atmospheric vapor-pressure deficit (VPD), photosynthetic active radiation (PAR), precipitation and soil moisture indicating the regulation of climate drivers on ecosystem WUE. In addition, it also was affected by aboveground net primary production (ANPP). The study suggests that ecosystem WUE responses to water and N addition is determined by the change in carbon process rather than that in water process, which are regulated by climate change in the temperate steppe of northern China.

Growth factor independence-1 antagonizes a p53-induced DNA damage response pathway in lymphoblastic leukemia

PubMed Central

Khandanpour, Cyrus; Phelan, James D.; Vassen, Lothar; Schütte, Judith; Chen, Riyan; Horman, Shane R.; Gaudreau, Marie-Claude; Krongold, Joseph; Zhu, Jinfang; Paul, William E.; Dührsen, Ulrich; Göttgens, Bertie; Grimes, H. Leighton; Möröy, Tarik

2013-01-01

Summary Most patients with acute lymphoblastic leukemia (ALL) fail current treatments highlighting the need for better therapies. Since oncogenic signaling activates a p53-dependent DNA-damage response and apoptosis, leukemic cells must devise appropriate countermeasures. We show here that growth factor independence 1 (Gfi1) can serve such a function, since Gfi1 ablation exacerbates p53 responses, and lowers the threshold for p53-induced cell death. Specifically, Gfi1 restricts p53 activity and expression of pro-apoptotic p53 targets such as Bax, Noxa (Pmaip1) and Puma (Bbc3). Subsequently, Gfi1 ablation cures mice from leukemia and limits the expansion of primary human T-ALL xenografts in mice. This suggests that targeting Gfi1 could improve the prognosis of patients with T-ALL or other lymphoid leukemias. PMID:23410974

Changes in net ecosystem productivity of boreal black spruce stands in response to changes in temperature at diurnal and seasonal time scales.

PubMed

Grant, R F; Margolis, H A; Barr, A G; Black, T A; Dunn, A L; Bernier, P Y; Bergeron, O

2009-01-01

Net ecosystem productivity (NEP) of boreal coniferous forests is believed to rise with climate warming, thereby offsetting some of the rise in atmospheric CO(2) concentration (C(a)) by which warming is caused. However, the response of conifer NEP to warming may vary seasonally, with rises in spring and declines in summer. To gain more insight into this response, we compared changes in CO(2) exchange measured by eddy covariance and simulated by the ecosystem process model ecosys under rising mean annual air temperatures (T(a)) during 2004-2006 at black spruce stands in Saskatchewan, Manitoba and Quebec. Hourly net CO(2) uptake was found to rise with warming at T(a) < 15 degrees C and to decline with warming at T(a) > 20 degrees C. As mean annual T(a) rose from 2004 to 2006, increases in net CO(2) uptake with warming at lower T(a) were greater than declines with warming at higher T(a) so that annual gross primary productivity and hence NEP increased. Increases in net CO(2) uptake measured at lower T(a) were explained in the model by earlier recovery of photosynthetic capacity in spring, and by increases in carboxylation activity, using parameters for the Arrhenius temperature functions of key carboxylation processes derived from independent experiments. Declines in net CO(2) uptake measured at higher T(a) were explained in the model by sharp declines in mid-afternoon canopy stomatal conductance (g(c)) under higher vapor pressure deficits (D). These declines were modeled from a hydraulic constraint to water uptake imposed by low axial conductivity of conifer roots and boles that forced declines in canopy water potential (psi(c)), and hence in g(c) under higher D when equilibrating water uptake with transpiration. In a model sensitivity study, the contrasting responses of net CO(2) uptake to specified rises in T(a) caused annual NEP of black spruce in the model to rise with increases in T(a) of up to 6 degrees C, but to decline with further increases at mid

Elevated Peritoneal Fluid TNF-α Incites Ovarian Early Growth Response Factor 1 Expression and Downstream Protease Mediators

PubMed Central

Birt, Julie A.; Nabli, Henda; Stilley, Julie A.; Windham, Emma A.; Frazier, Shellaine R.

2013-01-01

Endometriosis-associated infertility manifests itself via multiple, poorly understood mechanisms. Our goal was to characterize signaling pathways, between peritoneal endometriotic lesions and the ovary, leading to failed ovulation. Genome-wide microarray analysis comparing ovarian tissue from an in vivo endometriosis model in the rat (Endo) with controls (Sham) identified 22 differentially expressed genes, including transiently expressed early growth response factor 1 (Egr1). The Egr1 regulates gene requisites for ovulation. The Egr1 promoter is responsive to tumor necrosis factor-alpha (TNF-α) signaling. We hypothesized that altered expression of ovarian EGR1 is induced by elevated peritoneal fluid TNF-α which is upregulated by the presence of peritoneal endometriosis. Endo rats, compared to controls, had more peritoneal fluid TNF-α and quantitative, spatial differences in Egr1 mRNA and EGR1 protein localization in follicular compartments. Interactions between elevated peritoneal fluid TNF-α and overexpression of follicular Egr1/EGR1 expression may affect downstream protease pathways impeding ovulation in endometriosis. Preliminary studies identified similar patterns of EGR1 protein localization in human ovaries from women with endometriosis and compared to those without endometriosis. PMID:23427178

Injured nerve-derived COX2/PGE2 contributes to the maintenance of neuropathic pain in aged rats.

PubMed

Ma, Weiya; Chabot, Jean-Guy; Vercauteren, Freya; Quirion, Remi

2010-07-01

Neuropathic pain (NeP) is a debilitating disease afflicting mostly the aged population. Inflammatory responses in injured nerves play a pivotal role in the pathogenesis of NeP. Injured nerve derived cyclooxygenase 2/prostaglandin E2 (COX2/PGE2) contributes to the genesis of NeP at the early stage in young rats. Here we show that COX2/PGE2 is involved in the maintenance of NeP at a chronic stage in aged rats. Eighteen months after partial sciatic nerve ligation (PSNL), NeP remained prominent in aged rats. COX2 expressing macrophages and PGE2 levels were increased in injured nerves. PGE2 receptors (EP1 and EP4) and pain-related ion channel transient receptor potential vanilloid-1 (TRPV1) were increased in the ipsilateral dorsal root ganglion (DRG) neurons of aged PSNL rats. Perineural injection of a selective COX2 inhibitor NS-398 relieved NeP, reversed PSNL increased expression of EP1, EP4 and TRPV1 and suppressed the levels of pain-related peptide substance P and calcitonin gene-related peptide in DRG neurons. These data suggest that injured nerve-derived PGE2 contributes to the maintenance of NeP at the chronic stage in aged rats. Chronically facilitating the synthesis of pain-related molecules in nociceptive DRG neurons is a novel mechanism underpinning the contribution of PGE2. Copyright 2008 Elsevier Inc. All rights reserved.

The peptidase inhibitor CGS-26303 increases endothelin converting enzyme-1 expression in endothelial cells through accumulation of big endothelin-1

PubMed Central

Raoch, V; Martinez-Miguel, P; Arribas-Gomez, I; Rodriguez-Puyol, M; Rodriguez-Puyol, D; Lopez-Ongil, S

2007-01-01

Background and purpose: CGS-26303 inhibits endothelin converting enzyme (ECE)-1 more specifically than phosphoramidon. We have studied the effect of CGS-26303 on ECE-1 expression in bovine aortic endothelial cells. Methods: ECE-1 activity and big endothelin (ET)-1 levels were measured by ELISA, ECE-1 expression using western and northern blot and promoter activity using transfection assays. Key results: ECE-1 activity was completely inhibited by CGS-26303 25 μ M and phosphoramidon 100 μ M. CGS-26303 and phosphoramidon, though not thiorphan, a neutral endopeptidase (NEP) inhibitor, stimulated ECE-1 expression in cells (maximal effect at 16 h, 25 μ M). Cycloheximide abolished that effect. CGS-26303 induced ECE-1 mRNA expression and ECE-1 promoter activity. CGS-35066, a selective ECE-1 inhibitor, mimicked the effects of CGS-26303, suggesting that the effect was specific to ECE-1 inhibition. Big ET-1 accumulated in the cells and in the supernatants after CGS-26303 treatment. Neither exogenously added ET-1 nor the blockade of their receptors with bosentan modified ECE-1 protein. When big ET-1 was added to cells, significant increases in ECE-1 protein content and ECE-1 promoter activity were found. Bosentan did not block those effects. CGS-26303 did not modify prepro-ET-1 expression. CGS-26303 and big ET-1 induced the same effects in human endothelial cells, at lower doses. Conclusions: These results suggest that the accumulation of big ET-1 is responsible for the effects of CGS-26303 on ECE-1 and they did not depend on NEP blockade. Changes in ECE-1 protein after the administration of CGS-26303 could lead to a decreased response in long-term treatments. PMID:17643133

The effect of an inhaled neutral endopeptidase inhibitor, thiorphan, on airway responses to neurokinin A in normal humans in vivo.

PubMed

Cheung, D; Bel, E H; Den Hartigh, J; Dijkman, J H; Sterk, P J

1992-06-01

Neuropeptides such as neurokinin A (NKA) have been proposed as important mediators of bronchoconstriction and airway hyperresponsiveness in asthma. Inhaled NKA causes bronchoconstriction in patients with asthma, but not in normal subjects. This is possibly due to the activity of an endogenous neuropeptide-degrading enzyme: neutral endopeptidase (NEP). We investigated whether a NEP-inhibitor, thiorphan, reveals bronchoconstriction to NKA or NKA-induced changes in airway responsiveness to methacholine in normal humans in vivo. Eight normal male subjects participated in a double-blind crossover study, using thiorphan as pretreatment to NKA challenge. Dose-response curves to inhaled NKA (8 to 1,000 micrograms/ml, 0.5 ml/dose) were recorded on 2 randomized days 1 wk apart, and methacholine tests were performed 48 h before and 24 h after the NKA challenge. Ten minutes prior to NKA challenge the subjects inhaled either thiorphan (2.5 mg/ml, 0.5 ml) or placebo. To detect a possible nonspecific effect of thiorphan, we investigated the effect of the same pretreatment with thiorphan or placebo on the dose-response curve to methacholine in a separate set of experiments. The response was measured by the flow from standardized partial expiratory flow-volume curves (V40p), expressed in percent fall from baseline. NKA log dose-response curves were analyzed using the area under the curve (AUC) and the response to the highest dose of 1,000 micrograms/ml (V40p,1000). The methacholine dose-response curves were characterized by their position (PC40V40p) and the maximal-response plateau (MV40p). Baseline V40p was not affected by either pretreatment (p greater than 0.15).(ABSTRACT TRUNCATED AT 250 WORDS)

Targeted Morphoproteomic Profiling of Ewing's Sarcoma Treated with Insulin-Like Growth Factor 1 Receptor (IGF1R) Inhibitors: Response/Resistance Signatures

PubMed Central

Subbiah, Vivek; Naing, Aung; Brown, Robert E.; Chen, Helen; Doyle, Laurence; LoRusso, Patricia; Benjamin, Robert; Anderson, Pete; Kurzrock, Razelle

2011-01-01

Background Insulin-like growth factor 1 receptor (IGF1R) targeted therapies have resulted in responses in a small number of patients with advanced metastatic Ewing's sarcoma. We performed morphoproteomic profiling to better understand response/resistance mechanisms of Ewing's sarcoma to IGF1R inhibitor-based therapy. Methodology/Principal Findings This pilot study assessed two patients with advanced Ewing's sarcoma treated with IGF1R antibody alone followed by combined IGF1R inhibitor plus mammalian target of rapamycin (mTOR) inhibitor treatment once resistance to single-agent IGF1R inhibitor developed. Immunohistochemical probes were applied to detect p-mTOR (Ser2448), p-Akt (Ser473), p-ERK1/2 (Thr202/Tyr204), nestin, and p-STAT3 (Tyr 705) in the original and recurrent tumor. The initial remarkable radiographic responses to IGF1R-antibody therapy was followed by resistance and then response to combined IGF1R plus mTOR inhibitor therapy in both patients, and then resistance to the combination regimen in one patient. In patient 1, upregulation of p-Akt and p-mTOR in the tumor that relapsed after initial response to IGF1R antibody might explain the resistance that developed, and the subsequent response to combined IGF1R plus mTOR inhibitor therapy. In patient 2, upregulation of mTOR was seen in the primary tumor, perhaps explaining the initial response to the IGF1R and mTOR inhibitor combination, while the resistant tumor that emerged showed activation of the ERK pathway as well. Conclusion/Significance Morphoproteomic analysis revealed that the mTOR pathway was activated in these two patients with advanced Ewing's sarcoma who showed response to combined IGF1R and mTOR inhibition, and the ERK pathway in the patient in whom resistance to this combination emerged. Our pilot results suggests that morphoproteomic assessment of signaling pathway activation in Ewing's sarcoma merits further investigation as a guide to understanding response and resistance signatures. PMID

The Inhibitory Effects of Anti-Oxidants on Ultraviolet-Induced Up-Regulation of the Wrinkling-Inducing Enzyme Neutral Endopeptidase in Human Fibroblasts

PubMed Central

Nakajima, Hiroaki; Terazawa, Shuko; Niwano, Takao; Yamamoto, Yorihiro; Imokawa, Genji

2016-01-01

We recently reported that the over-expression of skin fibroblast-derived neutral endopeptidase (NEP) plays a pivotal role in impairing the three-dimensional architecture of dermal elastic fibers during the biological mechanism of ultraviolet (UV)-induced skin wrinkling. In that process, a UVB-associated epithelial-mesenchymal cytokine interaction as well as a direct UVA-induced cellular stimulation are associated with the up-regulation of NEP in human fibroblasts. In this study, we characterized the mode of action of ubiquinol10 which may abrogate the up-regulation of NEP by dermal fibroblasts, resulting in a reported in vivo anti-wrinkling action, and compared that with 3 other anti-oxidants, astaxanthin (AX), riboflavin (RF) and flavin mononucleotide (FMN). Post-irradiation treatment with all 4 of those anti-oxidants elicited an interrupting effect on the UVB-associated epithelial-mesenchymal cytokine interaction leading to the up-regulation of NEP in human fibroblasts but with different modes of action. While AX mainly served as an inhibitor of the secretion of wrinkle-inducing cytokines, such as interleukin-1α (IL-1α) and granulocyte macrophage colony stimulatory factor (GM-CSF) in UVB-exposed epidermal keratinocytes, ubiquinol10, RF and FMN predominantly interrupted the IL-1α and GM-CSF-stimulated expression of NEP in dermal fibroblasts. On the other hand, as for the UVA-associated mechanism, similar to the abrogating effects reported for AX and FMN, ubiquinol10 but not RF had the potential to abrogate the increased expression of NEP and matrix-metalloproteinase-1 in UVA-exposed human fibroblasts. Our findings strongly support the in vivo anti-wrinkling effects of ubiquinol10 and AX on human and animal skin and provide convincing proof of the UV-induced wrinkling mechanism that essentially focuses on the over-expression of NEP by dermal fibroblasts as an intrinsic causative factor. PMID:27648570

Role of substance P in cough.

PubMed

Sekizawa, K; Jia, Y X; Ebihara, T; Hirose, Y; Hirayama, Y; Sasaki, H

1996-01-01

The sensory neuropeptide, substance P (SP), is present in human airway nerves, beneath and within the epithelium where the condensed localization of neutral endopeptidase (NEP), the major enzyme degrading SP, is observed. To test the hypothesis whether SP stimulates the cough reflex and NEP modifies the cough reflex, we studied the cough response to various stimuli in awake guinea-pigs. Inhibition of NEP with phosphoramidon caused cough, which was inhibited by systemic capsaicin treatment and by aerosols of a specific NK1 receptor antagonist FK 888. Aerosols of FK 888 also inhibited cough induced by bronchoconstricting agents such as acetylcholine and histamine in non-sensitized animals and by ovalbumin antigen in animals sensitized to ovalbumin. The number of coughs induced by histamine aerosols was inhibited by systemic capsaicin treatment and enhanced by pretreatment with a NEP inhibitor phosphoramidon. Likewise, FK 888 inhibited the augmented cough response to aerosolized capsaicin in female guinea-pigs treated with a long-term medication of an angiotensin-converting enzyme inhibitor, cilazapril. In humans, aerosols of SP did not cause cough in normal subjects, whereas it did in patients with common colds. The SP fragment a major metabolite of SP produced by NEP, was less effective compared with SP in these patients, suggesting that damaged epithelium may facilitate the penetration of SP. These findings suggest that SP released from sensory nerves in response to stimuli may mediate cough and NEP may have a role in modulating SP-induced effects.

Basic helix-loop-helix transcription factors JASMONATE-ASSOCIATED MYC2-LIKE1 (JAM1), JAM2, and JAM3 are negative regulators of jasmonate responses in Arabidopsis.

PubMed

Sasaki-Sekimoto, Yuko; Jikumaru, Yusuke; Obayashi, Takeshi; Saito, Hikaru; Masuda, Shinji; Kamiya, Yuji; Ohta, Hiroyuki; Shirasu, Ken

2013-09-01

Jasmonates regulate transcriptional reprogramming during growth, development, and defense responses. Jasmonoyl-isoleucine, an amino acid conjugate of jasmonic acid (JA), is perceived by the protein complex composed of the F-box protein CORONATINE INSENSITIVE1 (COI1) and JASMONATE ZIM DOMAIN (JAZ) proteins, leading to the ubiquitin-dependent degradation of JAZ proteins. This activates basic helix-loop-helix-type MYC transcription factors to regulate JA-responsive genes. Here, we show that the expression of genes encoding other basic helix-loop-helix transcription factors, JASMONATE ASSOCIATED MYC2-LIKE1 (JAM1), JAM2, and JAM3, is positively regulated in a COI1- and MYC2-dependent manner in Arabidopsis (Arabidopsis thaliana). However, contrary to myc2, the jam1jam2jam3 triple mutant exhibited shorter roots when treated with methyl jasmonate (MJ), indicating enhanced responsiveness to JA. Our genome-wide expression analyses revealed that key jasmonate metabolic genes as well as a set of genes encoding transcription factors that regulate the JA-responsive metabolic genes are negatively regulated by JAMs after MJ treatment. Consistently, loss of JAM genes resulted in higher accumulation of anthocyanin in MJ-treated plants as well as higher accumulation of JA and 12-hydroxyjasmonic acid in wounded plants. These results show that JAMs negatively regulate the JA responses in a manner that is mostly antagonistic to MYC2.

Chemotaxis of primitive hematopoietic cells in response to stromal cell–derived factor-1

PubMed Central

Jo, Deog-Yeon; Rafii, Shahin; Hamada, Tsuneyoshi; Moore, Malcolm A.S.

2000-01-01

Stromal cell–derived factor-1 (SDF-1) provides a potent chemotactic stimulus for CD34+ hematopoietic cells. We cultured mobilized peripheral blood (PB) and umbilical cord blood (CB) for up to 5 weeks and examined the migratory activity of cobblestone area–forming cells (CAFCs) and long-term culture–initiating cells (LTC-ICs) in a transwell assay. In this system, SDF-1 or MS-5 marrow stromal cells placed in the lower chamber induced transmembrane and transendothelial migration by 2- and 5-week-old CAFCs and LTC-ICs in 3 hours. Transmigration was blocked by preincubation of input CD34+ cells with antibody to CXCR4. Transendothelial migration of CB CAFCs and LTC-ICs was higher than that of PB. We expanded CD34+ cells from CB in serum-free medium with thrombopoietin, flk-2 ligand, and c-kit ligand, with or without IL-3 and found that CAFCs cultured in the absence of IL-3 had a chemotactic response equivalent to noncultured cells, even after 5 weeks. However, addition of IL-3 to the culture reduced this response by 20–50%. These data indicate that SDF-1 induces chemotaxis of primitive hematopoietic cells signaling through CXCR4 and that the chemoattraction could be downmodulated by culture ex vivo. PMID:10619866

Quantifying Fast and Slow Responses of Terrestrial Carbon Exchange across a Water Availability Gradient in North American Flux Sites

NASA Astrophysics Data System (ADS)

Biederman, J. A.; Scott, R. L.; Goulden, M.

2014-12-01

Climate change is predicted to increase the frequency and severity of water limitation, altering terrestrial ecosystems and their carbon exchange with the atmosphere. Here we compare site-level temporal sensitivity of annual carbon fluxes to interannual variations in water availability against cross-site spatial patterns over a network of 19 eddy covariance flux sites. This network represents one order of magnitude in mean annual productivity and includes western North American desert shrublands and grasslands, savannahs, woodlands, and forests with continuous records of 4 to 12 years. Our analysis reveals site-specific patterns not identifiable in prior syntheses that pooled sites. We interpret temporal variability as an indicator of ecosystem response to annual water availability due to fast-changing factors such as leaf stomatal response and microbial activity, while cross-site spatial patterns are used to infer ecosystem adjustment to climatic water availability through slow-changing factors such as plant community and organic carbon pools. Using variance decomposition, we directly quantify how terrestrial carbon balance depends on slow- and fast-changing components of gross ecosystem production (GEP) and total ecosystem respiration (TER). Slow factors explain the majority of variance in annual net ecosystem production (NEP) across the dataset, and their relative importance is greater at wetter, forest sites than desert ecosystems. Site-specific offsets from spatial patterns of GEP and TER explain one third of NEP variance, likely due to slow-changing factors not directly linked to water, such as disturbance. TER and GEP are correlated across sites as previously shown, but our site-level analysis reveals surprisingly consistent linear relationships between these fluxes in deserts and savannahs, indicating fast coupling of TER and GEP in more arid ecosystems. Based on the uncertainty associated with slow and fast factors, we suggest a framework for improved

Applications of nuclear reactor power systems to electric propulsion missions.

NASA Technical Reports Server (NTRS)

Schaupp, R. W.; Sawyer, C. D.

1971-01-01

The performance of nuclear electric propulsion systems (NEP) has been evaluated for a wide variety of missions in an attempt to establish the commonality of NEP system requirements. Emphasis was given to those requirements and system characteristics that serve as guidelines for current technology development programs. Various interactions and tradeoffs between NEP system and mission parameters are described. The results show that the most significant factors in selecting NEP system size are launch mode (direct or spiral escape) and, to a weaker extent, launch vehicle capability. Other factors such as mission, payload, and thrust time constraints, have little influence, thus allowing one NEP system to be used for many missions. The results indicated that a 100 kWe NEP would be suitable for most direct escape missions and a 250 kWe NEP system would be suitable for more demanding missions that use the spiral escape mode.

The Serum Response Factor and a Putative Novel Transcription Factor Regulate Expression of the Immediate-Early Gene Arc/Arg3.1 in Cultured Cortical Neurons

PubMed Central

Pintchovski, Sean A.; Peebles, Carol L.; Kim, Hong Joo; Verdin, Eric; Finkbeiner, Steven

2010-01-01

The immediate-early effector gene Arc/Arg3.1 is robustly upregulated by synaptic activity associated with learning and memory. Here we show in primary cortical neuron culture that diverse stimuli induce Arc expression through new transcription. Searching for regulatory regions important for Arc transcription, we found nine DNaseI-sensitive nucleosome-depleted sites at this genomic locus. A reporter gene encompassing these sites responded to synaptic activity in an NMDA receptor–dependent manner, consistent with endogenous Arc mRNA. Responsiveness mapped to two enhancer regions ∼6.5 kb and ∼1.4 kb upstream of Arc. We dissected these regions further and found that the proximal enhancer contains a functional and conserved “Zeste-like” response element that binds a putative novel nuclear protein in neurons. Therefore, activity regulates Arc transcription partly by a novel signaling pathway. We also found that the distal enhancer has a functional and highly conserved serum response element. This element binds serum response factor, which is recruited by synaptic activity to regulate Arc. Thus, Arc is the first target of serum response factor that functions at synapses to mediate plasticity. PMID:19193899

HTLV-1 Tax upregulates early growth response protein 1 through nuclear factor-κB signaling

PubMed Central

Han, Jingxian; Liu, Xihong; Lv, Zhuangwei; Li, Huanhuan; Yuan, Lixiang; Li, Xiangping; Sun, Shuming; Wang, Hui; Huang, Xinxiang

2017-01-01

Human T cell leukemia virus type 1 (HTLV-1) is a complex retrovirus that causes adult T cell leukemia (ATL) in susceptible individuals. The HTLV-1-encoded oncoprotein Tax induces persistent activation of the nuclear factor-κB (NF-κB) pathway. Early growth response protein 1 (EGR1) is overexpressed in HTLV-1-infected T cell lines and ATL cells. Here, we showed that both Tax expression and HTLV-1 infection promoted EGR1 overexpression. Loss of the NF-κB binding site in the EGR1 promotor or inhibition of NF-κB activation reduced Tax-induced EGR1 upregulation. Tax mutants unable to activate NF-κB induced only slight EGR1 upregulation as compared with wild-type Tax, confirming NF-κB pathway involvement in EGR1 regulation. Tax also directly interacted with the EGR1 protein and increased endogenous EGR1 stability. Elevated EGR1 in turn promoted p65 nuclear translocation and increased NF-κB activation. These results demonstrate a positive feedback loop between EGR1 expression and NF-κB activation in HTLV-1-infected and Tax-expressing cells. Both NF-κB activation and Tax-induced EGR1 stability upregulated EGR1, which in turn enhanced constitutive NF-κB activation and facilitated ATL progression in HTLV-1-infected cells. These findings suggest EGR1 may be an effective anti-ATL therapeutic target. PMID:28881635

HTLV-1 Tax upregulates early growth response protein 1 through nuclear factor-κB signaling.

PubMed

Huang, Qingsong; Niu, Zhiguo; Han, Jingxian; Liu, Xihong; Lv, Zhuangwei; Li, Huanhuan; Yuan, Lixiang; Li, Xiangping; Sun, Shuming; Wang, Hui; Huang, Xinxiang

2017-08-01

Human T cell leukemia virus type 1 (HTLV-1) is a complex retrovirus that causes adult T cell leukemia (ATL) in susceptible individuals. The HTLV-1-encoded oncoprotein Tax induces persistent activation of the nuclear factor-κB (NF-κB) pathway. Early growth response protein 1 (EGR1) is overexpressed in HTLV-1-infected T cell lines and ATL cells. Here, we showed that both Tax expression and HTLV-1 infection promoted EGR1 overexpression. Loss of the NF-κB binding site in the EGR1 promotor or inhibition of NF-κB activation reduced Tax-induced EGR1 upregulation. Tax mutants unable to activate NF-κB induced only slight EGR1 upregulation as compared with wild-type Tax, confirming NF-κB pathway involvement in EGR1 regulation. Tax also directly interacted with the EGR1 protein and increased endogenous EGR1 stability. Elevated EGR1 in turn promoted p65 nuclear translocation and increased NF-κB activation. These results demonstrate a positive feedback loop between EGR1 expression and NF-κB activation in HTLV-1-infected and Tax-expressing cells. Both NF-κB activation and Tax-induced EGR1 stability upregulated EGR1, which in turn enhanced constitutive NF-κB activation and facilitated ATL progression in HTLV-1-infected cells. These findings suggest EGR1 may be an effective anti-ATL therapeutic target.

Arabidopsis WRKY45 transcription factor activates PHOSPHATE TRANSPORTER1;1 expression in response to phosphate starvation.

PubMed

Wang, Hui; Xu, Qian; Kong, You-Han; Chen, Yun; Duan, Jun-Ye; Wu, Wei-Hua; Chen, Yi-Fang

2014-04-01

The WRKY transcription factor family has more than 70 members in the Arabidopsis (Arabidopsis thaliana) genome, and some of them are involved in plant responses to biotic and abiotic stresses. This study evaluated the role of WRKY45 in regulating phosphate (Pi) uptake in Arabidopsis. WRKY45 was localized in the nucleus and mainly expressed in roots. During Pi starvation, WRKY45 expression was markedly induced, typically in roots. WRKY45 overexpression in Arabidopsis increased Pi content and uptake, while RNA interference suppression of WRKY45 decreased Pi content and uptake. Furthermore, the WRKY45-overexpressing lines were more sensitive to arsenate, the analog of Pi, compared with wild-type seedlings. These results indicate that WRKY45 positively regulates Arabidopsis Pi uptake. Quantitative real-time polymerase chain reaction and β-glucuronidase staining assays showed that PHOSPHATE TRANSPORTER1;1 (PHT1;1) expression was enhanced in the WRKY45-overexpressing lines and slightly repressed in the WRKY45 RNA interference line. Chromatin immunoprecipitation and electrophoretic mobility shift assay results indicated that WRKY45 can bind to two W-boxes within the PHT1;1 promoter, confirming the role of WRKY45 in directly up-regulating PHT1;1 expression. The pht1;1 mutant showed decreased Pi content and uptake, and overexpression of PHT1;1 resulted in enhanced Pi content and uptake. Furthermore, the PHT1;1-overexpressing line was much more sensitive to arsenate than WRKY45-overexpressing and wild-type seedlings, indicating that PHT1;1 overexpression can enhance Arabidopsis Pi uptake. Moreover, the enhanced Pi uptake and the increased arsenate sensitivity of the WRKY45-overexpressing line was impaired by pht1;1 (35S:WRKY45-18::pht1;1), demonstrating an epistatic genetic regulation between WRKY45 and PHT1;1. Together, our results demonstrate that WRKY45 is involved in Arabidopsis response to Pi starvation by direct up-regulation of PHT1;1 expression.

Neprilysin, obesity and the metabolic syndrome

PubMed Central

Standeven, Kristina F.; Hess, Katharina; Carter, Angela M.; Rice, Gillian I.; Cordell, Paul A.; Balmforth, Anthony J.; Lu, Bao; Scott, D. Julian; Turner, Anthony J.; Hooper, Nigel M.; Grant, Peter J.

2010-01-01

Objective Neprilysin (NEP), a zinc metallo-endopeptidase, has a role in blood pressure control and lipid metabolism. The present study tested the hypothesis that NEP is associated with insulin resistance and features of the metabolic syndrome (MetS) in a study of 318 healthy human subjects and in murine obesity and investigated NEP production by adipocytes in-vitro. Methods and Results In 318 white European males, plasma NEP was elevated in the MetS and increased progressively with increasing MetS components. Plasma NEP activity correlated with insulin, homeostasis model assessment and body mass index in all subjects (p<0.01). Quantitative RT-PCR and Western blotting showed that in human pre-adipocytes NEP expression is upregulated 25-30 fold during differentiation into adipocytes. Microarray analysis of mRNA from differentiated human adipocytes confirmed high NEP expression comparable to adiponectin and plasminogen activator inhibitor-1. In a murine model of diet-induced insulin resistance, plasma NEP levels were significantly higher in high fat diet (HFD)-fed compared with normal chow diet (NCD)-fed animals (1642±529 and 820±487 pg/μl, respectively; p<0.01). Tissue NEP was increased in mesenteric fat in HFD compared with NCD-fed mice (p<0.05). NEP knock out mice did not display any changes in insulin resistance, glucose tolerance or body and epididymal fat pad weight compared to wild type mice. Conclusions In humans, NEP activity correlated with body mass index and measures of insulin resistance with increasing levels in subjects with multiple cardiovascular risk factors. NEP protein production in human adipocytes increased during cell differentiation and plasma and adipose tissue levels of NEP were increased in obese insulin resistant mice. Our results indicate that NEP associates with cardio-metabolic risk in the presence of insulin resistance and increases in obesity. PMID:21042321

Effect of Neutralizing Transforming Growth Factor β1 on the Immune Response against Mycobacterium tuberculosis in Guinea Pigs

PubMed Central

Allen, Shannon Sedberry; Cassone, Lynne; Lasco, Todd M.; McMurray, David N.

2004-01-01

Transforming growth factor β (TGF-β) is a cytokine which has been shown to suppress the antimycobacterial immune responses of humans and experimental animals. In this study, the contributions of TGF-β to cytokine production in vivo were investigated by using the established guinea pig model of tuberculous pleurisy. Mycobacterium bovis BCG-vaccinated guinea pigs were injected intrapleurally with heat-killed virulent Mycobacterium tuberculosis. Eight days following induction of an antigen-specific pleural effusion, guinea pigs were injected intrapleurally with anti-TGF-β1 or isotype control antibody. The following day, pleural exudates were removed, and the fluid volume and characteristics of the infiltrating cells were determined. Pleural fluid was analyzed for total interferon (IFN) and tumor necrosis factor (TNF) protein levels by using appropriate bioassays. RNA from pleural effusion cells was examined to determine TGF-β1, TNF-α, IFN-γ, and interleukin-8 mRNA levels by using real-time PCR. Proliferative responses of pleural effusion lymphocytes were examined in response to concanavalin A and purified protein derivative (PPD) in vitro. Treatment with anti-TGF-β1 resulted in decreased pleural fluid volume and decreased cell numbers in the pleural space along with an increased percentage of lymphocytes and a decreased percentage of neutrophils. The bioactive TNF protein levels in pleural fluid were increased in guinea pigs treated with anti-TGF-β1, while the bioactive IFN protein concentrations were not altered. Expression of TGF-β1 and TNF-α mRNA was significantly increased following TGF-β1 neutralization. Finally, PPD-induced proliferative responses of pleural cells from anti-TGF-β1-treated animals were significantly enhanced. Thus, TGF-β1 may be involved in the resolution of this local, mycobacterial antigen-specific inflammatory response. PMID:14977939

Comparative Transcriptomics Highlights the Role of the Activator Protein 1 Transcription Factor in the Host Response to Ebolavirus

PubMed Central

Todd, Shawn; Boyd, Victoria; Tachedjian, Mary; Klein, Reuben; Shiell, Brian; Dearnley, Megan; McAuley, Alexander J.; Woon, Amanda P.; Purcell, Anthony W.; Marsh, Glenn A.; Baker, Michelle L.

2017-01-01

ABSTRACT Ebolavirus and Marburgvirus comprise two genera of negative-sense single-stranded RNA viruses that cause severe hemorrhagic fevers in humans. Despite considerable research efforts, the molecular events following Ebola virus (EBOV) infection are poorly understood. With the view of identifying host factors that underpin EBOV pathogenesis, we compared the transcriptomes of EBOV-infected human, pig, and bat kidney cells using a transcriptome sequencing (RNA-seq) approach. Despite a significant difference in viral transcription/replication between the cell lines, all cells responded to EBOV infection through a robust induction of extracellular growth factors. Furthermore, a significant upregulation of activator protein 1 (AP1) transcription factor complex members FOS and JUN was observed in permissive cell lines. Functional studies focusing on human cells showed that EBOV infection induces protein expression, phosphorylation, and nuclear accumulation of JUN and, to a lesser degree, FOS. Using a luciferase-based reporter, we show that EBOV infection induces AP1 transactivation activity within human cells at 48 and 72 h postinfection. Finally, we show that JUN knockdown decreases the expression of EBOV-induced host gene expression. Taken together, our study highlights the role of AP1 in promoting the host gene expression profile that defines EBOV pathogenesis. IMPORTANCE Many questions remain about the molecular events that underpin filovirus pathophysiology. The rational design of new intervention strategies, such as postexposure therapeutics, will be significantly enhanced through an in-depth understanding of these molecular events. We believe that new insights into the molecular pathogenesis of EBOV may be possible by examining the transcriptomic response of taxonomically diverse cell lines (derived from human, pig, and bat). We first identified the responsive pathways using an RNA-seq-based transcriptomics approach. Further functional and computational

High serum soluble tumor necrosis factor receptor 1 predicts poor treatment response in acute-stage schizophrenia.

PubMed

Nishimon, Shohei; Ohnuma, Tohru; Takebayashi, Yuto; Katsuta, Narimasa; Takeda, Mayu; Nakamura, Toru; Sannohe, Takahiro; Higashiyama, Ryoko; Kimoto, Ayako; Shibata, Nobuto; Gohda, Tomohito; Suzuki, Yusuke; Yamagishi, Sho-Ichi; Tomino, Yasuhiko; Arai, Heii

2017-06-02

Inflammation may be involved in the pathophysiology of schizophrenia. However, few cross-sectional or longitudinal studies have examined changes in biomarker expression to evaluate diagnostic and prognostic efficacy in acute-stage schizophrenia. We compared serum inflammatory biomarker concentrations in 87 patients with acute-stage schizophrenia on admission to 105 age-, sex-, and body mass index (BMI)-matched healthy controls. The measured biomarkers were soluble tumor necrosis factor receptor 1 (sTNFR1) and adiponectin, which are associated with inflammatory responses, and pigment epithelium-derived factor (PEDF), which has anti-inflammatory properties. We then investigated biomarker concentrations and associations with clinical factors in 213 patients (including 42 medication-free patients) and 110 unmatched healthy controls to model conditions typical of clinical practice. Clinical symptoms were assessed using the Brief Psychiatric Rating Scale and Global Assessment of Function. In 121 patients, biomarker levels and clinical status were evaluated at both admission and discharge. Serum sTNFR1 was significantly higher in patients with acute-stage schizophrenia compared to matched controls while no significant group differences were observed for the other markers. Serum sTNFR1 was also significantly higher in the 213 patients compared to unmatched controls. The 42 unmedicated patients had significantly lower PEDF levels compared to controls. Between admission and discharge, sTNFR1 levels decreased significantly; however, biomarker changes did not correlate with clinical symptoms. The discriminant accuracy of sTNFR1 was 93.2% between controls and patients, showing no symptom improvement during care. Inflammation and a low-level anti-inflammatory state may be involved in both schizophrenia pathogenesis and acute-stage onset. High serum sTNFR1 in the acute stage could be a useful prognostic biomarker for treatment response in clinical practice. Copyright © 2017

NOS1 mediates AP1 nuclear translocation and inflammatory response.

PubMed

Srivastava, Mansi; Baig, Mirza S

2018-06-01

A hallmark of the AP1 functioning is its nuclear translocation, which induces proinflammatory cytokine expression and hence the inflammatory response. After endotoxin shock AP1 transcription factor, which comprises Jun, ATF2, and Fos family of proteins, translocates into the nucleus and induces proinflammatory cytokine expression. In the current study, we found, NOS1 inhibition prevents nuclear translocation of the AP1 transcription factor subunits. Pharmacological inhibition of NOS1 impedes translocation of subunits into the nucleus, suppressing the transcription of inflammatory genes causing a diminished inflammatory response. In conclusion, the study shows the novel mechanism of NOS1- mediated AP1 nuclear translocation, which needs to be further explored. Copyright © 2018 Elsevier Masson SAS. All rights reserved.

TdERF1, an ethylene response factor associated with dehydration responses in durum wheat (Triticum turgidum L. subsp. durum).

PubMed

Makhloufi, Emna; Yousfi, Fatma-Ezzahra; Pirrello, Julien; Bernadac, Anne; Ghorbel, Abdelwahed; Bouzayen, Mondher

2015-01-01

Water deficit and increasing salinization reduce productivity of wheat, the leading crop for human diet. While the complete genome sequence of this crop has not been deciphered, a BAC library screening allowed the isolation of TdERF1, the first ethylene response factor gene from durum wheat. This gene is putatively involved in mediating salt stress tolerance and its characterization provides clues toward understanding the mechanisms underlying the adaptation/tolerance of durum wheat to suboptimal growth conditions. TdERF1 expression is differentially induced by high salt treatment in 2 durum wheat varieties, the salt-tolerant Grecale (GR) and the salt-sensitive Om Rabiaa (OR). To further extend these findings, we show here that the expression of this ERF is correlated with physiological parameters, such as the accumulation of osmo-regulators and membrane integrity, that discriminate between the 2 contrasted wheat genotypes. The data confirm that GR and OR are 2 contrasted wheat genotypes with regard to salt-stress and show that TdERF1 is also induced by water stress with an expression pattern clearly discriminating between the 2 genotypes. These findings suggest that TdERF1 might be involved in responses to salt and water stress providing a potential genetic marker discriminating between tolerant and sensitive wheat varieties.

CD10/neutral endopeptidase 24.11 in developing human fetal lung. Patterns of expression and modulation of peptide-mediated proliferation.

PubMed

Sunday, M E; Hua, J; Torday, J S; Reyes, B; Shipp, M A

1992-12-01

The cell membrane-associated enzyme CD10/neutral endopeptidase 24.11 (CD10/NEP) functions in multiple organ systems to downregulate responses to peptide hormones. Recently, CD10/NEP was found to hydrolyze bombesin-like peptides (BLP), which are mitogens for normal bronchial epithelial cells and small cell lung carcinomas. Growth of BLP-responsive small cell lung carcinomas was potentiated by CD10/NEP inhibition, implicating CD10/NEP in regulation of BLP-mediated tumor growth. BLP are also likely to participate in normal lung development because high BLP levels are found in fetal lung, and bombesin induces proliferation and maturation of human fetal lung in organ cultures and murine fetal lung in utero. To explore potential roles for CD10/NEP in regulating peptide-mediated human fetal lung development, we have characterized temporal and cellular patterns of CD10/NEP expression and effects of CD10/NEP inhibition in organ cultures. Peak CD10/NEP transcript levels are identified at 11-13 wk gestation by Northern blots and localized to epithelial cells and mesenchyme of developing airways by in situ hybridization. CD10/NEP immunostaining is most intense in undifferentiated airway epithelium. In human fetal lung organ cultures, inhibition of CD10/NEP with either phosphoramidon or SCH32615 increases thymidine incorporation by 166-182% (P < 0.025). The specific BLP receptor antagonist, [Leu13-psi(CH2NH)Leu14]bombesin abolishes these effects on fetal lung growth, suggesting that CD10/NEP modulates BLP-mediated proliferation. CD10/NEP expression in the growing front of airway epithelium and the effects of CD10/NEP inhibitors in lung explants implicate the enzyme in the regulation of peptide-mediated fetal lung growth.

Neutral endopeptidase inhibition in diabetic wound repair.

PubMed

Spenny, Michelle L; Muangman, Pornprom; Sullivan, Stephen R; Bunnett, Nigel W; Ansel, John C; Olerud, John E; Gibran, Nicole S

2002-01-01

In response to cutaneous injury, sensory nerves release substance P, a proinflammatory neuropeptide. Substance P stimulates mitogenesis and migration of keratinocytes, fibroblasts, and endothelial cells. Neutral endopeptidase (NEP), a cell surface metallopeptidase, degrades substance P. Chronic nonhealing wounds and skin from patients with diabetes mellitus show increased NEP localization and activity. We hypothesized that increased NEP may retard wound healing and that NEP inhibition would improve closure kinetics in an excisional murine wound model. NEP enzyme activity was measured in skin samples from mutant diabetic mice (db/db) and nondiabetic (db/-) littermates by degradation of glutaryl-ala-ala-phe-4-methoxy-2-naphthylamine. Full-thickness 6-mm dorsal excisional wounds treated with normal saline or the NEP inhibitor thiorphan (10 microM or 25 microM) for 7 days were followed until closure. Histological examination and NEP activity were evaluated in a subset of wounds. NEP activity in unwounded db/db skin (20.6 pmol MNA/hr/ microg) significantly exceeded activity in db/-skin (7.9 pmol MNA/hr/ microg; p = 0.02). In db/db mice, 25 microM thiorphan shortened time to closure (18.0 days; p < 0.05) compared to normal saline (23.5 days). NEP inhibition did not alter closure kinetics in db/-mice. While the inflammatory response appeared enhanced in early wounds treated with thiorphan, blinded histological scoring of healed wounds using a semiquantitative scale showed no difference in inflammation. Unwounded skin from diabetic mice shows increased NEP activity and NEP inhibition improved wound closure kinetics without affecting contraction, suggesting that its principal effect was to augment epithelialization.

Water and carbon dioxide fluxes over an alpine meadow in southwest China and the impact of a spring drought event.

PubMed

Wang, Lei; Liu, Huizhi; Sun, Jihua; Feng, Jianwu

2016-02-01

Based on the eddy covariance measurements from June 2011 to December 2013, the seasonal variations and the controls of water and CO2 fluxes were investigated over an alpine meadow in Lijiang, southwest China. The year 2012 had the largest total precipitation among years from 2011 to 2013 (1037.9, 1190.4, and 1066.1 mm, respectively). A spring drought event occurred from March to May 2012, and the peak normalized difference vegetation index (NDVI) in 2012 was the lowest. Throughout the whole year, net radiation (Rn), vapor pressure deficit, and air temperature (Ta) were the primary controls on evapotranspiration (ET), and R n is the most important factor. The influence of R n on ET was much more in the wet season (R(2) = 0.93) than in the dry season (R(2) = 0.28). In the wet season, the ratio of ET to equilibrium ET (ETeq) (0.92 ± 0.14; mean ± S.D.) did not show a clear seasonal pattern with NDVI when the soil water content (SWC) was usually more than 0.25 m(3) m(-3), indicating that ET could be predicted well by ETeq (or radiation and temperature). On half-hourly and daily scales, photosynthetic active radiation (PAR) and air temperature were the main meteorological factors in determining the net ecosystem production (NEP). The seasonal trends of NEP were closely related with the change of NDVI. The integrated NEP in the 2012 wet season (157.8 g C m(-2) year(-1)) was 19.5 and 23.8 % lower than in the 2011 and 2013 wet season (207.0 and 196.1 g C m(-2) year(-1)). The mean ET/ETeq for each of the wet seasons from 2011 to 2013 was 0.88. The 2012 spring drought and its reduction in NDVI decreased the total NEP significantly but had little effect on the total ET in the wet season. The different response of NEP and ET to the spring drought was attributed to the high SWC and small vapor pressure deficit during the wet season.

Impacts of droughts on carbon sequestration by China's terrestrial ecosystems from 2000 to 2011

NASA Astrophysics Data System (ADS)

Liu, Y.; Zhou, Y.; Ju, W.; Wang, S.; Wu, X.; He, M.; Zhu, G.

2014-05-01

In recent years, China's terrestrial ecosystems have experienced frequent droughts. How these droughts have affected carbon sequestration by the terrestrial ecosystems is still unclear. In this study, the process-based Boreal Ecosystem Productivity Simulator (BEPS) model, driven by remotely sensed vegetation parameters, was employed to assess the effects of droughts on net ecosystem productivity (NEP) of terrestrial ecosystems in China from 2000 to 2011. Droughts of differing severity, as indicated by a standard precipitation index (SPI), hit terrestrial ecosystems in China extensively in 2001, 2006, 2009, and 2011. The national total annual NEP exhibited the slight decline of -11.3 Tg C yr-2 during the aforementioned years of extensive droughts. The NEP reduction ranged from 61.1 Tg C yr-1 to 168.8 Tg C yr-1. National and regional total NEP anomalies were correlated with the annual mean SPI, especially in Northwest China, North China, Central China, and Southwest China. The reductions in annual NEP in 2001 and 2011 might have been caused by a larger decrease in annual gross primary productivity (GPP) than in annual ecosystem respiration (ER). The reductions experienced in 2009 might be due to a decrease in annual GPP and an increase in annual ER, while reductions in 2006 could stem from a larger increase in ER than in GPP. The effects of droughts on NEP lagged up to 3-6 months, due to different responses of GPP and ER. In eastern China, where is humid and warm, droughts have predominant and short-term lagged influences on NEP. In western regions, cold and arid, the drought effects on NEP were relatively weaker but prone to lasting longer.

The translation elongation factor eEF1A1 couples transcription to translation during heat shock response

PubMed Central

Vera, Maria; Pani, Bibhusita; Griffiths, Lowri A; Muchardt, Christian; Abbott, Catherine M; Singer, Robert H; Nudler, Evgeny

2014-01-01

Translation elongation factor eEF1A has a well-defined role in protein synthesis. In this study, we demonstrate a new role for eEF1A: it participates in the entire process of the heat shock response (HSR) in mammalian cells from transcription through translation. Upon stress, isoform 1 of eEF1A rapidly activates transcription of HSP70 by recruiting the master regulator HSF1 to its promoter. eEF1A1 then associates with elongating RNA polymerase II and the 3′UTR of HSP70 mRNA, stabilizing it and facilitating its transport from the nucleus to active ribosomes. eEF1A1-depleted cells exhibit severely impaired HSR and compromised thermotolerance. In contrast, tissue-specific isoform 2 of eEF1A does not support HSR. By adjusting transcriptional yield to translational needs, eEF1A1 renders HSR rapid, robust, and highly selective; thus, representing an attractive therapeutic target for numerous conditions associated with disrupted protein homeostasis, ranging from neurodegeneration to cancer. DOI: http://dx.doi.org/10.7554/eLife.03164.001 PMID:25233275

Evidence for metalloprotease involvement in the in vivo effects of big endothelin 1.

PubMed

Pollock, D M; Opgenorth, T J

1991-07-01

The potent vasoconstrictor endothelin 1 (ET-1) is thought to arise from the proteolytic processing of big endothelin 1 (Big ET) by a unique endothelin-converting enzyme, possibly a metalloprotease. Experiments were conducted to determine the effects of Big ET on cardiovascular and renal functions during inhibition of metalloprotease activity in vivo. Intravenous infusion of Big ET (0.1 nmol.kg-1.min-1) in anesthetized euvolemic rats produced a significant increase in mean arterial pressure (MAP; 39 +/- 8%) and a decrease in effective renal plasma flow (ERPF; -39 +/- 2%), whereas glomerular filtration rate (GFR) remained unchanged (-8 +/- 8%). Simultaneous intravenous infusion of phosphoramidon (0.25 mg.kg-1.min-1), an inhibitor of metalloprotease activity including neutral endopeptidase EC 3.4.24.11 (NEP), completely prevented these effects of Big ET. Thiorphan (0.1 mg.kg-1.min-1), also an inhibitor of NEP, had absolutely no effect on either the renal or cardiovascular response to Big ET. Similarly, the response to Big ET was unaffected by infusion of enalaprilat (0.1 mg.kg-1.min-1), an inhibitor of the angiotensin-converting enzyme, which is also a metalloprotease. To determine whether the effect of phosphoramidon was due to antagonism of ET-1, an identical series of experiments was performed using ET-1 infusion (0.02 nmol.kg-1.min-1). Although the increase in MAP (24 +/- 5%) produced by ET-1 was less than that observed for the given dose of Big ET, the renal vasoconstriction was much more severe; the smaller peptide changed ERPF and GFR by -66 +/- 7 and -54 +/- 9%, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Deciphering the role of the signal- and Sty1 kinase-dependent phosphorylation of the stress-responsive transcription factor Atf1 on gene activation.

PubMed

Salat-Canela, Clàudia; Paulo, Esther; Sánchez-Mir, Laura; Carmona, Mercè; Ayté, José; Oliva, Baldo; Hidalgo, Elena

2017-08-18

Adaptation to stress triggers the most dramatic shift in gene expression in fission yeast ( Schizosaccharomyces pombe ), and this response is driven by signaling via the MAPK Sty1. Upon activation, Sty1 accumulates in the nucleus and stimulates expression of hundreds of genes via the nuclear transcription factor Atf1, including expression of atf1 itself. However, the role of stress-induced, Sty1-mediated Atf1 phosphorylation in transcriptional activation is unclear. To this end, we expressed Atf1 phosphorylation mutants from a constitutive promoter to uncouple Atf1 activity from endogenous, stress-activated Atf1 expression. We found that cells expressing a nonphosphorylatable Atf1 variant are sensitive to oxidative stress because of impaired transcription of a subset of stress genes whose expression is also controlled by another transcription factor, Pap1. Furthermore, cells expressing a phospho-mimicking Atf1 mutant display enhanced stress resistance, and although expression of the Pap1-dependent genes still relied on stress induction, another subset of stress-responsive genes was constitutively expressed in these cells. We also observed that, in cells expressing the phospho-mimicking Atf1 mutant, the presence of Sty1 was completely dispensable, with all stress defects of Sty1-deficient cells being suppressed by expression of the Atf1 mutant. We further demonstrated that Sty1-mediated Atf1 phosphorylation does not stimulate binding of Atf1 to DNA but, rather, establishes a platform of interactions with the basal transcriptional machinery to facilitate transcription initiation. In summary, our results provide evidence that Atf1 phosphorylation by the MAPK Sty1 is required for oxidative stress responses in fission yeast cells by promoting transcription initiation. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

Suppression of in vivo polyclonal IgE responses by monoclonal antibody to the lymphokine B-cell stimulatory factor 1.

PubMed Central

Finkelman, F D; Katona, I M; Urban, J F; Snapper, C M; Ohara, J; Paul, W E

1986-01-01

The lymphokine B-cell stimulatory factor 1 (BSF-1) has been shown to greatly enhance the differentiation of lipopolysaccharide-activated B cells into IgG1- and IgE-secreting cells in vitro. To determine whether in vivo IgG1 and IgE antibody responses are BSF-1 dependent, the ability of a monoclonal rat IgG1 anti-BSF-1 antibody, 11B11, to affect polyclonal IgG1 and IgE production in mice infected with the nematode parasite Nippostrongylus brasiliensis or injected with a purified goat antibody to mouse IgD was studied. 11B11-containing ascites fluid or purified 11B11 strongly inhibited IgE production in both systems but did not affect IgG1 production, while control ascites or normal rat IgG1 had no IgE-inhibitory activity. These results indicate an important physiologic role for BSF-1 in the generation of IgE antibody responses and suggest means for limiting the production of antibodies responsible for allergic reactions without inhibiting protective antibody responses. PMID:3491987

The effect of acute angiotensin-converting enzyme and neutral endopeptidase 24.11 inhibition on plasma extravasation in the rat.

PubMed

Sulpizio, Anthony C; Pullen, Mark A; Edwards, Richard M; Brooks, David P

2004-06-01

The effect of angiotensin-converting enzyme (ACE) and neutral endopeptidase (NEP) inhibition on microvascular plasma leakage (extravasation) was evaluated in a rat model. Progressive inhibition of ACE using captopril caused increased extravasation when lung ACE was inhibited by >55%. In contrast, the selective inhibition of renal NEP by >90% using ecadotril did not increase extravasation. In NEP-inhibited rats, extravasation produced by the ACE inhibitors captopril and lisinopril was markedly enhanced. The dual ACE and NEP inhibitor omapatrilat, at oral doses of 0.03, 0.1, and 0.3 mg/kg, selectively inhibited lung ACE by 19, 61, and 76%, respectively, and did not cause significant extravasation. Doses of 1 and 10 mg/kg omapatrilat, which produced >90% inhibition of ACE and also inhibited renal NEP by 54 and 78%, respectively, significantly increased extravasation. In this model, bradykinin and substance P produced extravasation that could be abolished by the bradykinin 2 (B2) receptor antagonist Hoe 140 (icatibant) or the neurokinin1 (NK1) antagonist CP99994 [(+)-(2S,3S)-3-(2-methoxybenzylamino)-2-phenylpiperidine], respectively. Bradykinin induced extravasation was also partially ( approximately 40%) inhibited by CP99994, indicating that a portion of the response involves B2 receptor-mediated release of substance P. In conclusion, this study is the first to relate the degree of ACE and/or NEP inhibition to extravasation liability in the rat model. Our data clearly demonstrate that ACE inhibitor-induced plasma extravasation is enhanced by concomitant inhibition of NEP. In addition, this study provides further evidence for the role for B2 and NK1 receptors in mediating plasma extravasation in the rat.

Sex differences in corticotropin-releasing factor receptor-1 action within the dorsal raphe nucleus in stress responsivity.

PubMed

Howerton, Alexis R; Roland, Alison V; Fluharty, Jessica M; Marshall, Anikò; Chen, Alon; Daniels, Derek; Beck, Sheryl G; Bale, Tracy L

2014-06-01

Women are twice as likely as men to suffer from stress-related affective disorders. Corticotropin-releasing factor (CRF) is an important link between stress and mood, in part through its signaling in the serotonergic dorsal raphe (DR). Development of CRF receptor-1 (CRFr1) antagonists has been a focus of numerous clinical trials but has not yet been proven efficacious. We hypothesized that sex differences in CRFr1 modulation of DR circuits might be key determinants in predicting therapeutic responses and affective disorder vulnerability. Male and female mice received DR infusions of the CRFr1 antagonist, NBI 35965, or CRF and were evaluated for stress responsivity. Sex differences in indices of neural activation (cFos) and colocalization of CRFr1 throughout the DR were examined. Whole-cell patch-clamp electrophysiology assessed sex differences in serotonin neuron membrane characteristics and responsivity to CRF. Males showed robust behavioral and hypothalamic-pituitary-adrenal axis responses to DR infusion of NBI 35965 and CRF, whereas females were minimally responsive. Sex differences were also found for both CRF-induced DR cFos and CRFr1 co-localization throughout the DR. Electrophysiologically, female serotonergic neurons showed blunted membrane excitability and divergent inhibitory postsynaptic current responses to CRF application. These studies demonstrate convincing sex differences in CRFr1 activity in the DR, where blunted female responses to NBI 35965 and CRF suggest unique stress modulation of the DR. These sex differences might underlie affective disorder vulnerability and differential sensitivity to pharmacologic treatments developed to target the CRF system, thereby contributing to a current lack of CRFr1 antagonist efficacy in clinical trials. © 2013 Published by Society of Biological Psychiatry on behalf of Society of Biological Psychiatry.

Rapid changes in substance P signaling and neutral endopeptidase induced by skin-scratching stimulation in mice.

PubMed

Yamaoka, Junichi; Kawana, Seiji

2007-11-01

Skin-scratching is a commonly seen behavior in patients with pruritus which sometimes exacerbates original lesions. Substance P (SP) signaling may play a predominant role in the pathophysiology induced by skin-scratching, however, it has not been well-elucidated. To clarify changes in SP, its receptor NK-1R and a degradating enzyme neutral endopeptidase (NEP) induced by skin-scratching stimulation in mice. After skin-scratching stimulation was given to mice, changes in SP signaling were investigated as follows. Mast cell degranulation was examined with toluidine blue staining. SP-immunoreactive nerve fibers and the expressions of NK-1R and NEP were examined with immunofluorescence. Protein contents of SP and the enzymatic activity of NEP were examined with an ELISA and a colorimetric assay, respectively. After skin-scratching stimulation, mast cells significantly degranulated within several minutes. SP-immunoreactive nerve fibers disappeared immediately from sensory nerve fibers, indicating the quick secretion and the depletion of SP. Both protein contents of SP and NEP activity in skin decreased dramatically soon after skin-scratching stimulation and thereafter they returned to the basal level within a week. The expression of NK-1R was significantly upregulated in epidermal basal keratinocytes after several days, in which NEP and NK-1R were well-coexpressed. Blocking NK-1R by an NK-1R antagonist suppressed scratching-induced decreases in SP-immunoreactive nerve fibers and in NEP activity. The present study clarified changing patterns of factors involved in SP signaling and NEP induced by skin-scratching stimulation. These findings provide basic and useful information to understand the pathophysiology of scratching-associated pruritic skin diseases.

[Effect of seasonal high temperature and drought on carbon flux of bamboo forest ecosystem in subtropical region].

PubMed

Chen, Xiao-feng; Jiang, Hong; Niu, Xiao-dong; Zhang, Jin-meng; Liu, Yu-li; Fang, Cheng-yuan

2016-02-01

The carbon flux of subtropical bamboo forest ecosystem was continuously measured using eddy covariance technique in Anji County of Zhejiang Province, China. The monthly net ecosystem productivity (NEP), ecosystem respiration (Re) and gross ecosystem productivity (GEP) data from 2011 to 2013 were selected to analyze the impacts of seasonal high temperature and drought on the carbon flux of bamboo forest ecosystem. The results showed that there were big differences among annual NEP of bamboo forest from 2011 to 2013. Because of the asynchronization of precipitation and heat, the seasonal high temperature and drought in July and August of 2013 caused significant decline in NEP by 59.9% and 80.0% when compared with the same months in 2011. Correlation analysis of the NEP, Re, GEP and environmental factors suggested that the atmosphere temperatures were significantly correlated with Re and GEP in 2011 and 2013 (P<0.05). However, to air and soil moisture, Re and GEP had different responses, that was, GEP was more vulnerable by the decrease of the soil moisture compared with Re. Besides, the raising of saturation vapour pressure promoted the Re modestly but inhibited the GEP, which was supposed to be the main reason for NEP decrease of bamboo forest ecosystem in Anji, from July to August in 2013.

Ethylene Responsive Factor MeERF72 Negatively Regulates Sucrose synthase 1 Gene in Cassava.

PubMed

Liu, Chen; Chen, Xin; Ma, Ping'an; Zhang, Shengkui; Zeng, Changying; Jiang, Xingyu; Wang, Wenquan

2018-04-25

Cassava, an important food and industrial crop globally, is characterized by its powerful starch accumulation in its storage root. However, the underlying molecular mechanism for this feature remains unclear. Sucrose synthase initializes the conversion of sucrose to starch, and, to a certain extent, its enzyme activity can represent sink strength. To understand the modulation of MeSus gene family, the relatively high expressed member in storage root, MeSus1 , its promoter was used as bait to screen cassava storage root full-length cDNA library through a yeast one-hybrid system. An ethylene responsive factor cDNA, designated as MeERF72 according to its homolog in Arabidopsis , was screened out. The transcript level of MeERF72 was induced by ethylene, drought, and salt treatments and repressed by abscisic acid, Auxin, gibberellin, salicylic acid, and low and high temperatures. The MeERF72 protein has a conserved APETALA2 domain in its N-terminus and an activated domain of 30 amino acids in its C-terminus, can bind to MeSus1 promoter in vitro and in vivo, and represses the promoter activity of MeSus1 . MeERF72 is a transcription factor that can negatively regulate the expression level of MeSus1 in cassava.

Malat1 regulates serum response factor through miR-133 as a competing endogenous RNA in myogenesis.

PubMed

Han, Xiaorui; Yang, Feng; Cao, Huiqing; Liang, Zicai

2015-07-01

Metastasis-associated lung adenocarcinoma transcript 1 (Malat1) is an example of a functional long noncoding RNA involved in many biologic processes. However, the mechanisms for Malat1 in myogenesis are unclear. Serum response factor (SRF) is a pivotal transcription factor for muscle proliferation and differentiation and is reported to be a target gene for muscle-specific microRNA-133 (miR-133). In this study, we initially found that silencing Malat1 in the mouse myoblast C2C12 cell line inhibited myocyte differentiation and decreased Srf at both the RNA and protein levels. Srf silencing decreased Malat1 expression as well. Further study revealed that Malat1 contained an miR-133 functional target site, and the interplay between Malat1 and Srf was miR-133 dependent. We demonstrated that Malat1 modulates Srf through miR-133 as a competing endogenous RNA and established a novel connection among Malat1, miR-133, and Srf in myoblast differentiation. © FASEB.

pH modulates the binding of early growth response protein 1 transcription factor to DNA.

PubMed

Mikles, David C; Bhat, Vikas; Schuchardt, Brett J; Deegan, Brian J; Seldeen, Kenneth L; McDonald, Caleb B; Farooq, Amjad

2013-08-01

The transcription factor early growth response protein (EGR)1 orchestrates a plethora of signaling cascades involved in cellular homeostasis, and its downregulation has been implicated in the development of prostate cancer. Herein, using a battery of biophysical tools, we show that the binding of EGR1 to DNA is tightly regulated by solution pH. Importantly, the binding affinity undergoes an enhancement of more than an order of magnitude with an increase in pH from 5 to 8, implying that the deprotonation of an ionizable residue accounts for such behavior. This ionizable residue is identified as His382 by virtue of the fact that its replacement by nonionizable residues abolishes the pH dependence of the binding of EGR1 to DNA. Notably, His382 inserts into the major groove of DNA, and stabilizes the EGR1-DNA interaction via both hydrogen bonding and van der Waals contacts. Remarkably, His382 is mainly conserved across other members of the EGR family, implying that histidine protonation-deprotonation may serve as a molecular switch for modulating the protein-DNA interactions that are central to this family of transcription factors. Collectively, our findings reveal an unexpected but a key step in the molecular recognition of the EGR family of transcription factors, and suggest that they may act as sensors of pH within the intracellular environment. © 2013 FEBS.

Overexpression of early growth response-1 as a metastasis-regulatory factor in gastric cancer.

PubMed

Kobayashi, Daisuke; Yamada, Mikako; Kamagata, Chinatsu; Kaneko, Reiko; Tsuji, Naoki; Nakamura, Masashi; Yagihashi, Atsuhito; Watanabe, Naoki

2002-01-01

To investigate the potential role of a nuclear transcription factor, early growth response-1 (Egr-1), in formation and progression of gastric cancer, we compared its expression in gastric cancers with that in non-cancerous tissues. Egr-1 mRNA expression was measured using TaqMan RT-PCR. The corresponding protein expression was examined immunohistochemically. Egr-1 mRNA expression was significantly higher in gastric cancer tissues than in normal mucosa (p < 0.0005). These differences were also reflected by protein product expression. Moreover, Egr-1 mRNA expression was higher in cases with metastasis to lymph nodes or remote organs. In cultured gastric cancer cells known to have a high metastatic potential, expression of this mRNA was higher than that of parental cells. It was suggested that Egr-1 has a significant role in carcinogenesis and in cancer progression, especially metastasis. Measurement of this mRNA should be useful for evaluation of the metastatic potential of gastric cancer.

Influence of management and precipitation on carbon fluxes in greatplains grasslands

USGS Publications Warehouse

Rigge, Matthew B.; Wylie, Bruce K.; Zhang, Li; Boyte, Stephen P.

2013-01-01

Suitable management and sufficient precipitation on grasslands can provide carbon sinks. The net carbon accumulation of a site from the atmosphere, modeled as the Net Ecosystem Productivity (NEP), is a useful means to gauge carbon balance. Previous research has developed methods to integrate flux tower data with satellite biophysical datasets to estimate NEP across large regions. A related method uses the Ecosystem Performance Anomaly (EPA) as a satellite-derived indicator of disturbance intensity (e.g., livestock stocking rate, fire, and insect damage). To better understand the interactions among management, climate, and carbon dynamics, we evaluated the relationship between EPA and NEP data at the 250 m scale for grasslands in the Central Great Plains, USA (ranging from semi-arid to mesic). We also used weekly estimates of NEP to evaluate the phenology of carbon dynamics, classified by EPA (i.e., by level of disturbance impact). Results show that the cumulative carbon balance over these grasslands from 2000 to 2008 was a weak net sink of 13.7 g C m−2 yr−1. Overall, NEP increased with precipitation (R2 = 0.39, P < 0.05) from west to east. Disturbance influenced NEP phenology; however, climate and biophysical conditions were usually more important. The NEP response to disturbance varies by ecoregion, and more generally by grassland type, where the shortgrass prairie NEP is most sensitive to disturbance, the mixed-grass prairie displays a moderate response, and tallgrass prairie is the least impacted by disturbance (as measured by EPA). Sustainable management practices in the tallgrass and mixed-grass prairie may potentially induce a period of average net carbon sink until a new equilibrium soil organic carbon is achieved. In the shortgrass prairie, management should be considered sustainable if carbon stocks are simply maintained. The consideration of site carbon balance adds to the already difficult task of managing grasslands appropriately to site conditions

EGFR ligands drive multipotential stromal cells to produce multiple growth factors and cytokines via early growth response-1.

PubMed

Kerpedjieva, Svetoslava S; Kim, Duk Soo; Barbeau, Dominique J; Tamama, Kenichi

2012-09-01

Cell therapy with adult bone marrow multipotential stromal cells/mesenchymal stem cells (MSCs) presents a promising approach to promote wound healing and tissue regeneration. The strong paracrine capability of various growth factors and cytokines is a key mechanism of MSC-mediated wound healing and tissue regeneration, and the goal of this study is to understand the underlying mechanism that supports the strong paracrine machineries in MSCs. Microarray database analyses revealed that early growth response-1 (EGR1) is highly expressed in MSCs. Our previous studies showed that epidermal growth factor (EGF) treatment induces growth factor production in MSCs in vitro. Since EGF strongly upregulates EGR1, we hypothesized that EGF receptor (EGFR)-EGR1 signaling plays a pivotal role in MSC paracrine activity. EGF treatment upregulated the gene expression of growth factors and cytokines, including EGFR ligands in a protein kinase C (PKC)- and/or mitogen-activated protein kinase-extracellular-signal-regulated kinase-dependent manner, and it was reversed by shRNA against EGR1. PKC activator phorbol 12-myristate 13-acetate enhanced EGFR tyrosyl phosphorylation and upregulated the gene expression of growth factors and cytokines in a heparin-binding EGF-like growth factor (HBEGF) inhibitor CRM197 sensitive manner, indicating an involvement of autocrined HBEGF in the downstream of PKC signaling. Moreover, stimulation with growth factors and cytokines induced the expression of EGFR ligands, presumably via EGR1 upregulation. These data indicate EGR1 as a convergence point of multiple signaling pathways, which in turn augments the production of multiple growth factors and cytokines by enhancing the autocrine signaling with EGFR ligands.

Upscaling carbon fluxes over the Great Plains grasslands: Sinks and sources

USGS Publications Warehouse

Zhang, Li; Wylie, Bruce K.; Ji, Lei; Gilmanov, Tagir G.; Tieszen, Larry L.; Howar, Daniel M.

2011-01-01

Previous studies suggested that the grasslands may be carbon sinks or near equilibrium, and they often shift between carbon sources in drought years and carbon sinks in other years. It is important to understand the responses of net ecosystem production (NEP) to various climatic conditions across the U.S. Great Plains grasslands. Based on 15 grassland flux towers, we developed a piecewise regression model and mapped the grassland NEP at 250 m spatial resolution over the Great Plains from 2000 to 2008. The results showed that the Great Plains was a net sink with an averaged annual NEP of 24 ± 14 g C m−2 yr−1, ranging from a low value of 0.3 g C m−2 yr−1 in 2002 to a high value of 47.7 g C m−2 yr−1 in 2005. The regional averaged NEP for the entire Great Plains grasslands was estimated to be 336 Tg C yr−1 from 2000 to 2008. In the 9 year period including 4 dry years, the annual NEP was very variable in both space and time. It appeared that the carbon gains for the Great Plains were more sensitive to droughts in the west than the east. The droughts in 2000, 2002, 2006, and 2008 resulted in increased carbon losses over drought-affected areas, and the Great Plains grasslands turned into a relatively low sink with NEP values of 15.8, 0.3, 20.1, and 10.2 g C m−2 yr−1 for the 4 years, respectively.

Neutral endopeptidase (EC 3.4.24.11) downregulates the onset of intestinal inflammation in the nematode infected mouse.

PubMed

Barbara, G; De Giorgio, R; Stanghellini, V; Corinaldesi, R; Cremon, C; Gerard, N; Gerard, C; Grady, E F; Bunnett, N W; Blennerhassett, P A; Collins, S M

2003-10-01

Substance P (SP) release from sensory nerves induces neurogenic inflammation. Neutral endopeptidase (NEP) degrades SP, thereby limiting its proinflammatory effects. Intestinal inflammation following Trichinella spiralis infection markedly downregulates NEP, resulting in diminished SP degradation, with unknown functional consequences. We hypothesised that diminished expression of NEP would exacerbate T spiralis induced enteritis. NEP knockout (NEP-/-) and wild-type (NEP+/+) mice were infected with T spiralis and studied at 6, 12, 24, and 48 hours post infection (PI). Tissue inflammation was quantified by computerised cell counting and myeloperoxidase activity (MPO). The leucocyte adhesion molecule, intercellular adhesion molecule 1 (ICAM-1), and SP were assessed by immunohistochemistry. Before infection, the lack of NEP was not associated with changes in mucosal cellularity or MPO activity. Twelve hours PI, NEP-/- mice showed a 2.5-fold increase in MPO activity at a time when values in NEP+/+ mice were still within normal limits. MPO activity and cellularity peaked at 24 hours PI. This was accompanied by increased staining for both ICAM-1 and SP in NEP-/- mice. Infusion of rhNEP to NEP-/- mice significantly reduced MPO activity 24 hours PI. These findings demonstrate that NEP downregulates the early onset of nematode intestinal inflammation and that increased bioavailability of SP and overexpression of ICAM-1 in NEP-/- mice likely play a role in the earlier onset of intestinal inflammation.

Pleiotrophin, a multifunctional cytokine and growth factor, induces leukocyte responses through the integrin Mac-1.

PubMed

Shen, Di; Podolnikova, Nataly P; Yakubenko, Valentin P; Ardell, Christopher L; Balabiyev, Arnat; Ugarova, Tatiana P; Wang, Xu

2017-11-17

Pleiotrophin (PTN) is a multifunctional, cationic, glycosaminoglycan-binding cytokine and growth factor involved in numerous physiological and pathological processes, including tissue repair and inflammation-related diseases. PTN has been shown to promote leukocyte responses by inducing their migration and expression of inflammatory cytokines. However, the mechanisms through which PTN mediates these responses remain unclear. Here, we identified the integrin Mac-1 (αMβ2, CD11b/CD18) as the receptor mediating macrophage adhesion and migration to PTN. We also found that expression of Mac-1 on the surface of human embryonic kidney (HEK) 293 cells induced their adhesion and migration to PTN. Accordingly, PTN promoted Mac-1-dependent cell spreading and initiated intracellular signaling manifested in phosphorylation of Erk1/2. While binding to PTN, Mac-1 on Mac-1-expressing HEK293 cells appears to cooperate with cell-surface proteoglycans because both anti-Mac-1 function-blocking mAb and heparin were required to block adhesion. Moreover, biolayer interferometry and NMR indicated a direct interaction between the α M I domain, the major ligand-binding region of Mac-1, and PTN. Using peptide libraries, we found that in PTN the α M I domain bound sequences enriched in basic and hydrophobic residues, indicating that PTN conforms to the general principle of ligand-recognition specificity of the α M I domain toward cationic proteins/peptides. Finally, using recombinant PTN-derived fragments, we show that PTN contains two distinct Mac-1-binding sites in each of its constitutive domains. Collectively, these results identify PTN as a ligand for the integrin Mac-1 on the surface of leukocytes and suggest that this interaction may play a role in inflammatory responses. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

EGFR Ligands Drive Multipotential Stromal Cells to Produce Multiple Growth Factors and Cytokines via Early Growth Response-1

PubMed Central

Kerpedjieva, Svetoslava S.; Kim, Duk Soo; Barbeau, Dominique J.

2012-01-01

Cell therapy with adult bone marrow multipotential stromal cells/mesenchymal stem cells (MSCs) presents a promising approach to promote wound healing and tissue regeneration. The strong paracrine capability of various growth factors and cytokines is a key mechanism of MSC-mediated wound healing and tissue regeneration, and the goal of this study is to understand the underlying mechanism that supports the strong paracrine machineries in MSCs. Microarray database analyses revealed that early growth response-1 (EGR1) is highly expressed in MSCs. Our previous studies showed that epidermal growth factor (EGF) treatment induces growth factor production in MSCs in vitro. Since EGF strongly upregulates EGR1, we hypothesized that EGF receptor (EGFR)–EGR1 signaling plays a pivotal role in MSC paracrine activity. EGF treatment upregulated the gene expression of growth factors and cytokines, including EGFR ligands in a protein kinase C (PKC)- and/or mitogen-activated protein kinase–extracellular-signal-regulated kinase-dependent manner, and it was reversed by shRNA against EGR1. PKC activator phorbol 12-myristate 13-acetate enhanced EGFR tyrosyl phosphorylation and upregulated the gene expression of growth factors and cytokines in a heparin-binding EGF-like growth factor (HBEGF) inhibitor CRM197 sensitive manner, indicating an involvement of autocrined HBEGF in the downstream of PKC signaling. Moreover, stimulation with growth factors and cytokines induced the expression of EGFR ligands, presumably via EGR1 upregulation. These data indicate EGR1 as a convergence point of multiple signaling pathways, which in turn augments the production of multiple growth factors and cytokines by enhancing the autocrine signaling with EGFR ligands. PMID:22316125

Cigarette smoke induces bronchoconstrictor hyperresponsiveness to substance P and inactivates airway neutral endopeptidase in the guinea pig. Possible role of free radicals.

PubMed

Dusser, D J; Djokic, T D; Borson, D B; Nadel, J A

1989-09-01

We examined the effects of acute exposure to cigarette smoke on the airway responses to substance P in anesthetized guinea pigs and on the activity of airway neutral endopeptidase (NEP). After exposure to air or to cigarette smoke we measured the change in total pulmonary resistance (RL) induced by increasing concentrations of aerosolized substance P in the absence or presence of the NEP inhibitor phosphoramidon. In the absence of phosphramidon the bronchoconstrictor responses to substance P were greater in cigarette smoke-exposed guinea pigs than in air-exposed animals. Phosphoramidon did not further potentiate the responses to substance P in smoke-exposed guinea pigs, whereas it did so in air-exposed animals. In the presence of phosphoramidon, bronchoconstrictor responses to substance P in animals exposed to air or to cigarette smoke were not different. Aerosols of SOD delivered before cigarette smoke exposures dramatically reduced smoke-induced hyperresponsiveness to substance P, whereas heat-inactivated SOD had no effect on smoke-induced hyper-responsiveness to substance P. Cigarette smoke solution inhibited NEP activity from tracheal homogenate in a concentration-dependent fashion, an inhibitory effect that was mostly due to the gas phase of the smoke, but not to nicotine. The mild chemical oxidant N-chlorosuccinimide mimicked the concentration-dependent inhibitory effect of smoke solution on airway NEP activity. We conclude that cigarette smoke causes enhanced airway responsiveness to substance P in vivo by inactivating airway NEP. We suggest that cigarette smoke-induced inhibition of airway NEP is due to effects of free radicals.

Cigarette smoke induces bronchoconstrictor hyperresponsiveness to substance P and inactivates airway neutral endopeptidase in the guinea pig. Possible role of free radicals.

PubMed Central

Dusser, D J; Djokic, T D; Borson, D B; Nadel, J A

1989-01-01

We examined the effects of acute exposure to cigarette smoke on the airway responses to substance P in anesthetized guinea pigs and on the activity of airway neutral endopeptidase (NEP). After exposure to air or to cigarette smoke we measured the change in total pulmonary resistance (RL) induced by increasing concentrations of aerosolized substance P in the absence or presence of the NEP inhibitor phosphoramidon. In the absence of phosphramidon the bronchoconstrictor responses to substance P were greater in cigarette smoke-exposed guinea pigs than in air-exposed animals. Phosphoramidon did not further potentiate the responses to substance P in smoke-exposed guinea pigs, whereas it did so in air-exposed animals. In the presence of phosphoramidon, bronchoconstrictor responses to substance P in animals exposed to air or to cigarette smoke were not different. Aerosols of SOD delivered before cigarette smoke exposures dramatically reduced smoke-induced hyperresponsiveness to substance P, whereas heat-inactivated SOD had no effect on smoke-induced hyper-responsiveness to substance P. Cigarette smoke solution inhibited NEP activity from tracheal homogenate in a concentration-dependent fashion, an inhibitory effect that was mostly due to the gas phase of the smoke, but not to nicotine. The mild chemical oxidant N-chlorosuccinimide mimicked the concentration-dependent inhibitory effect of smoke solution on airway NEP activity. We conclude that cigarette smoke causes enhanced airway responsiveness to substance P in vivo by inactivating airway NEP. We suggest that cigarette smoke-induced inhibition of airway NEP is due to effects of free radicals. PMID:2474576

Integration of growth factor signals at the c-fos serum response element.

PubMed

Price, M A; Hill, C; Treisman, R

1996-04-29

A transcription factor ternary complex composed of serum response factor (SRF) and a second factor, ternary complex factor (TCF), mediates the response of the c-fos Serum Response Element to growth factors and mitogens. In NIH3T3 fibroblasts, TCF binding is required for transcriptional activation by the SRE in response to activation of the Ras-Raf-ERK pathway. We compared the properties of three members of the TCF family, Elk-1, SAP-1 and SAP-2 (ERP/NET). Although all the proteins contain sequences required for ternary complex formation with SRF, only Elk-1 and SAP-1 appear to interact with the c-fos SRE efficiently in vivo. Each TCF contains a C-terminal activation domain capable of transcriptional activation in response to activation of the Ras-Raf-ERK pathway, and this is dependent on the integrity of S/T-P motifs conserved between all the TCF family members. In contrast, activation of the SRE by whole serum and the mitogenic phospholipid LPA requires SRF binding alone. Constitutively activated members of the Rho subfamily of Ras-like GTPases are also capable of inducing activation of the SRE in the absence of TCF; unlike activated Ras itself, these proteins do not activate the TCFs in NIH3T3 cells. At the SRE, SRF- and TCF-linked signalling pathways act synergistically to potentiate transcription.

Neutral endopeptidase inhibitors potentiate substance P-induced contraction in gut smooth muscle.

PubMed

Djokic, T D; Sekizawa, K; Borson, D B; Nadel, J A

1989-01-01

To determine the role of endogenous neutral endopeptidase (NEP), also called enkephalinase (EC 3.4.24.11), in regulating tachykinin-induced contraction of gut smooth muscle, we studied the effects of NEP inhibitors on the contractile responses to substance P (SP) in isolated longitudinal strips of ileum or duodenum in rats and ferrets. Leucine-thiorphan and phosphoramidon shifted the concentration-response curves of SP to lower concentrations in all tissues studied, but the sensitivity to SP was greater and the effect of leucine-thiorphan was less in the ferret, a finding that correlated with the observation that the ferret ileum contained substantially less NEP activity than rat ileum. Captopril, bestatin, MGTA, leupeptin, and physostigmine did not alter contractile responses to SP, suggesting that kininase II, aminopeptidases, carboxypeptidase N, serine proteinases, and acetylcholinesterase do not modulate the SP-induced effects. These studies suggest that, in the ileum and duodenum, NEP modulates the actions of SP and, furthermore, that the sensitivity of tissues may be determined, at least in part, by the amount of enzymatically active NEP present.

Response to Growth Hormone Treatment in a Patient with Insulin-Like Growth Factor 1 Receptor Deletion

PubMed Central

Mahmoud, Ranim; Naidu, Ajanta; Risheg, Hiba; Kimonis, Virginia

2017-01-01

We report a six-year-old boy who presented with short stature, microcephaly, dysmorphic features, and developmental delay and who was identified with a terminal deletion of 15q26.2q26.3 containing the insulin-like growth factor receptor (IGF1R) gene in addition to a terminal duplication of the 4q35.1q35.2 region. We compare our case with other reports of deletions and mutations affecting the IGF1R gene associated with pre-and postnatal growth restriction. We report the dramatic response to growth hormone therapy in this patient which highlights the importance of identifying patients with IGF1R deletion and treating them early. PMID:28720553

Response to Growth Hormone Treatment in a Patient with Insulin-Like Growth Factor 1 Receptor Deletion.

PubMed

Mahmoud, Ranim; Naidu, Ajanta; Risheg, Hiba; Kimonis, Virginia

2017-12-15

We report a six-year-old boy who presented with short stature, microcephaly, dysmorphic features, and developmental delay and who was identified with a terminal deletion of 15q26.2q26.3 containing the insulin-like growth factor receptor (IGF1R) gene in addition to a terminal duplication of the 4q35.1q35.2 region. We compare our case with other reports of deletions and mutations affecting the IGF1R gene associated with pre-and postnatal growth restriction. We report the dramatic response to growth hormone therapy in this patient which highlights the importance of identifying patients with IGF1R deletion and treating them early.

HIV-1 Tat-mediated induction of Platelet-derived Growth Factor in Astrocytes: Role of Early Growth Response Gene 1

PubMed Central

Bethel-Brown, Crystal; Yao, Honghong; Callen, Shannon; Lee, Young Han; Dash, Prasanta K; Kumar, Anil; Buch, Shilpa

2011-01-01

HIV-associated neurological disorders (HAND) are estimated to affect almost 60% of HIV infected individuals. HIV-encephalitis (HIVE), the pathological correlate of the most severe form of HAND is often characterized by glial activation, cytokine/chemokine dysregulation, and neuronal damage and loss. However, the severity of HIVE correlates better with glial activation rather than viral load. Using the macaque model, it has been demonstrated that simian immunodeficiency virus encephalitis (SIVE) correlates with increased expression of the mitogen platelet-derived growth factor-B (PDGF-B) chain in the brain. The present study was aimed at exploring the role of PDGF-B chain in HIV-associated activation and proliferation of astrocytes. Specifically, the data herein demonstrate that exposure of rat and human astrocytes to the HIV-1 protein, Tat resulted in the induction of PDGF at both the mRNA and protein levels. Furthermore, PDGF-BB induction was regulated by activation of ERK1/2 and JNK signaling pathways and the downstream transcription factor, early growth response 1(Egr-1). Chromatin immunoprecipitation (ChIP) assays demonstrated binding of Egr-1 to the PDGF-B promoter. Exposure of astrocytes to PDGF-BB, in turn, led to both increased proliferation and release of pro-inflammatory cytokines MCP-1 and IL-1β. Since astrogliosis is linked to disease severity, understanding its regulation by PDGF-BB could aid in the development of therapeutic intervention strategies for HAND. PMID:21368226

Resveratrol regulates gene transcription via activation of stimulus-responsive transcription factors.

PubMed

Thiel, Gerald; Rössler, Oliver G

2017-03-01

Resveratrol (trans-3,4',5-trihydroxystilbene), a polyphenolic phytoalexin of grapes and other fruits and plants, is a common constituent of our diet and of dietary supplements. Many health-promoting benefits have been connected with resveratrol in the treatment of cardiovascular diseases, cancer, diabetes, inflammation, neurodegeneration, and diseases connected with aging. To explain the pleiotropic effects of resveratrol, the molecular targets of this compound have to be identified on the cellular level. Resveratrol induces intracellular signal transduction pathways which ultimately lead to changes in the gene expression pattern of the cells. Here, we review the effect of resveratrol on the activation of the stimulus-responsive transcription factors CREB, AP-1, Egr-1, Elk-1, and Nrf2. Following activation, these transcription factors induce transcription of delayed response genes. The gene products of these delayed response genes are ultimately responsible for the changes in the biochemistry and physiology of resveratrol-treated cells. The activation of stimulus-responsive transcription factors may explain many of the intracellular activities of resveratrol. However, results obtained in vitro may not easily be transferred to in vivo systems. Copyright © 2016 Elsevier Ltd. All rights reserved.

Ternary Complex Factors and Cofactors Are Essential for Human T-Cell Leukemia Virus Type 1 Tax Transactivation of the Serum Response Element

PubMed Central

Shuh, Maureen; Derse, David

2000-01-01

The human T-cell leukemia virus type 1 Tax protein activates the expression of cellular immediate early genes controlled by the serum response element (SRE), which contains both the serum response factor (SRF) binding element (CArG box) and the ternary complex factor (TCF) binding element (Ets box). We show that TCF binding is necessary for Tax activation of the SRE and that Tax directly interacts with TCFs in vitro. In addition, Tax interactions with CREB binding protein (CBP) and p300- and CBP-associated factor were found to be essential for Tax activation of SRF-mediated transcription. PMID:11070040

Modification of tissue-factor mRNA and protein response to thrombin and interleukin 1 by high glucose in cultured human endothelial cells.

PubMed

Boeri, D; Almus, F E; Maiello, M; Cagliero, E; Rao, L V; Lorenzi, M

1989-02-01

Because diabetic vascular disease is accompanied by a state of hypercoagulability, manifested by increased thrombin activity and foci of intravascular coagulation, we investigated whether a specific procoagulant property of the endothelium--production and surface expression of tissue factor--is modified by elevated glucose concentrations. In unperturbed human vascular endothelial cells, tissue factor mRNA and expression of the functional protein were undetectable and were not induced by 10-12 days of exposure to 30 mM glucose. In thrombin-stimulated cultures, tissue-factor expression was related inversely to cellular density, with confluent cultures producing (per 10(5) cells) half the amount of tissue factor measured in sparse cultures. Cells exposed to high glucose and studied when cell number and thymidine incorporation were identical to control cells manifested increased tissue-factor mRNA level and functional protein production in response to thrombin (P = .002). This effect was not attributable to hypertonicity and was not observed after short exposure to high glucose. In contrast, the tissue-factor response to interleukin 1, a modulator of endothelial function in the context of host defense, was decreased in cells cultured in high glucose (P = .04). These findings indicate that exposure to high glucose can alter tissue-factor gene expression in perturbed vascular endothelium. The reciprocal effects of high glucose on the tissue-factor response to thrombin and interleukin 1 points to different pathways of tissue-factor stimulation by the two agents and suggests functional consequences pertinent to the increased thrombin activity and compromised host-defense mechanisms observed in diabetes.

Differential modulation of degradative and repair responses of interleukin-1-treated chondrocytes by platelet-derived growth factor.

PubMed Central

Harvey, A K; Stack, S T; Chandrasekhar, S

1993-01-01

Interleukin 1 (IL-1) plays a dual role in cartilage matrix degeneration by promoting extracellular proteinase action such as the matrix metalloproteinases (increased degradation) and by suppressing the synthesis of extracellular matrix molecules (inhibition of repair). Platelet-derived growth factor (PDGF) is a wound-healing hormone which is released along with IL-1 during the inflammatory response. Since previous studies have shown that PDGF enhances IL-1 alpha effects on metalloproteinase activity, in this report, we have examined whether PDGF modifies IL-1 beta effects on cartilage proteoglycan synthesis. Initially, we confirmed that rabbit articular chondrocytes treated with IL-1 beta + PDGF induced higher proteinase activity, in comparison with IL-1-treated cells. We further observed that the increased proteinase activity correlated with an increase in the synthesis of collagenase/stromelysin proteins and a corresponding increase in the steady-state mRNA levels for both the enzymes. Studies on IL-1 receptor expression suggested that PDGF caused an increase in IL-1 receptor expression which, by augmenting the IL-1 response, may have led to the increase in proteinase induction. Analysis of proteoglycan synthesis confirmed that IL-1 reduced the incorporation of sulphated proteoglycan, aggrecan, into the extracellular matrix of chondrocytes, whereas PDGF stimulated it. However, cells treated with IL-1 + PDGF synthesized normal levels of aggrecan. This is in contrast with cells treated with IL-1 + fibroblast growth factor, in which case only proteinase activity was potentiated. The results allow us to conclude that (a) the two effector functions that play a role in matrix remodelling, namely matrix lysis (proteinase induction) and matrix repair (proteoglycan synthesis), occur via distinct pathways and (b) PDGF may play a crucial role in cartilage repair by initially causing matrix degradation followed by promoting new matrix synthesis. Images Figure 1 Figure 2

VIP1 is very important/interesting protein 1 regulating touch responses of Arabidopsis.

PubMed

Tsugama, Daisuke; Liu, Shenkui; Takano, Tetsuo

2016-06-02

VIP1 (VIRE2-INTERACTING PROTEIN 1) is a bZIP transcription factor in Arabidopsis thaliana. VIP1 and its close homologs (i.e., Arabidopsis group I bZIP proteins) are present in the cytoplasm under steady conditions, but are transiently localized to the nucleus when cells are exposed to hypo-osmotic conditions, which mimic mechanical stimuli such as touch. Recently we have reported that overexpression of a repression domain-fused form of VIP1 represses the expression of some touch-responsive genes, changes structures and/or local auxin responses of the root cap cells, and enhances the touch-induced root waving. This raises the possibility that VIP1 suppresses touch-induced responses. VIP1 should be useful to further characterize touch responses of plants. Here we discuss 2 seemingly interesting perspectives about VIP1: (1) What factors are involved in regulating the nuclear localization of VIP1?; (2) What can be done to further characterize the physiological functions of VIP1 and other Arabidopsis group I bZIP proteins?

Pacific Northwest Regional and Ecozone-scale Carbon Cycle Responses to 25 Years of Variation in Climate and Disturbance

NASA Astrophysics Data System (ADS)

Turner, D. P.; Ritts, W. D.; Kennedy, R. E.; Gray, A. N.; Yang, Z.

2015-12-01

Spatial variation in climate, soils, disturbance regime, and forest management - as well as temporal variation in weather - all influence terrestrial carbon sources and sinks. Spatially-distributed, process-based, carbon cycle simulation models provide a means to integrate information from these various influences to estimate carbon pools and flux over large domains. Here we apply the Biome-BGC model over the 4 state (OR, WA, ID, Western MT) Northwest U.S. region for the interval from 1986-2010. Landsat data was used to characterize disturbances and revealed that the overall disturbance rate on forest land across the region was 0.8 % yr-1, with 49 % as harvests, 28 % as fire, and 23 % as pest/pathogen. A large proportion of the harvested area was on private forestland (62 %) and a large proportion of total burned area was on public forestland (89 %). Net ecosystem production (NEP) for the 2006-2010 interval on forestland was predominantly positive (a carbon sink) throughout the region, with maximum values in the Coast Range, intermediate values in the Cascade Mountains, and relatively low values in the Inland Rocky Mountain ecoregions. Croplands throughout the region had consistently high NEP. Localized negative NEPs were mostly associated with recent disturbances. There was large interannual variation in regional NEP, with notably low values across the region in 2003. In all ecoregions there was a downward trend in NEP over the 25 year study period. The net ecosystem carbon balance was positive in OR, near neutral in ID and WA, and negative (a carbon source) MT. The Northwest region as a whole was a carbon sink in the 2006-2010 period.

Neprilysin participates in skeletal muscle regeneration and is accumulated in abnormal muscle fibres of inclusion body myositis.

PubMed

Broccolini, Aldobrando; Gidaro, Teresa; Morosetti, Roberta; Gliubizzi, Carla; Servidei, Tiziana; Pescatori, Mario; Tonali, Pietro A; Ricci, Enzo; Mirabella, Massimiliano

2006-02-01

Neprilysin (NEP, EP24.11), a metallopeptidase originally shown to modulate signalling events by degrading small regulatory peptides, is also an amyloid-beta- (Abeta) degrading enzyme. We investigated a possible role of NEP in inclusion body myositis (IBM) and other acquired and hereditary muscle disorders and found that in all myopathies NEP expression was directly associated with the degree of muscle fibre regeneration. In IBM muscle, NEP protein was also strongly accumulated in Abeta-bearing abnormal fibres. In vitro, during the experimental differentiation of myoblasts, NEP protein expression was regulated at the post-transcriptional level with a rapid increase in the early stage of myoblast differentiation followed by a gradual reduction thereafter, coincident with the progression of the myogenic programme. Treatment of differentiating muscle cells with the NEP inhibitor dl-3-mercapto-2-benzylpropanoylglycine resulted in impaired differentiation that was mainly associated with an abnormal regulation of Akt activation. Therefore, NEP may play an important role during muscle cell differentiation, possibly through the regulation, either directly or indirectly, of the insulin-like growth factor I-driven myogenic programme. In IBM muscle increased NEP may be instrumental in (i) reducing the Abeta accumulation in vulnerable fibres and (ii) promoting a repair/regenerative attempt of muscle fibres possibly through the modulation of insulin-like growth factor I-dependent pathways.

TERATOGENIC RESPONSES ARE MODULATED IN MICE LACKING EXPRESSION OF EPIDERMAL GROWTH FACTOR (EGF) AND TRANSFORMING GROWTH FACTOR-ALPHA (TGF)

EPA Science Inventory

TITLE:
TERATOGENIC RESPONSES ARE MODULATED IN MICE LACKING EXPRESSION OF EPIDERMAL GROWTH FACTOR (EGF) AND TRANSFORMING GROWTH FACTOR-ALPHA (TGF). AUTHORS (ALL): Abbott, Barbara D.1; Best, Deborah S.1; Narotsky, Michael G.1. SPONSOR NAME: None INSTITUTIONS (ALL): 1. Repro Tox ...

Pilot Evaluation of Angiogenesis Signaling Factor Response after Transcatheter Arterial Embolization for Hepatocellular Carcinoma.

PubMed

Ronald, James; Nixon, Andrew B; Marin, Daniele; Gupta, Rajan T; Janas, Gemini; Chen, Willa; Suhocki, Paul V; Pabon-Ramos, Waleska; Sopko, David R; Starr, Mark D; Brady, John C; Hurwitz, Herbert I; Kim, Charles Y

2017-10-01

Purpose To identify changes in a broad panel of circulating angiogenesis factors after bland transcatheter arterial embolization (TAE), a purely ischemic treatment for hepatocellular carcinoma (HCC). Materials and Methods This prospective HIPAA-compliant study was approved by the institutional review board. Informed written consent was obtained from all participants prior to entry into the study. Twenty-five patients (21 men; mean age, 61 years; range, 30-81 years) with Liver Imaging Reporting and Data System category 5 or biopsy-proven HCC and who were undergoing TAE were enrolled from October 15, 2014, through December 2, 2015. Nineteen plasma angiogenesis factors (angiopoietin 2; hepatocyte growth factor; platelet-derived growth factor AA and BB; placental growth factor; vascular endothelial growth factor A and D; vascular endothelial growth factor receptor 1, 2, and 3; osteopontin; transforming growth factor β1 and β2; thrombospondin 2; intercellular adhesion molecule 1; interleukin 6 [IL-6]; stromal cell-derived factor 1; tissue inhibitor of metalloproteinases 1; and vascular cell adhesion molecule 1 [VCAM-1]) were measured by using enzyme-linked immunosorbent assays at 1 day, 2 weeks, and 5 weeks after TAE and were compared with baseline levels by using paired Wilcoxon tests. Tumor response was assessed according to modified Response Evaluation Criteria in Solid Tumors (mRECIST). Angiogenesis factor levels were compared between responders and nonresponders by mRECIST criteria by using unpaired Wilcoxon tests. Results All procedures were technically successful with no complications. Fourteen angiogenesis factors showed statistically significant changes following TAE, but most changes were transient. IL-6 was upregulated only 1 day after the procedure, but showed the largest increases of any factor. Osteopontin and VCAM-1 demonstrated sustained upregulation at all time points following TAE. At 3-month follow-up imaging, 11 patients had responses to TAE

Sialorphin, a natural inhibitor of rat membrane-bound neutral endopeptidase that displays analgesic activity

PubMed Central

Rougeot, Catherine; Messaoudi, Michaël; Hermitte, Véronique; Rigault, Anne Gaëlle; Blisnick, Thierry; Dugave, Christophe; Desor, Didier; Rougeon, François

2003-01-01

Sialorphin is an exocrine and endocrine signaling mediator, which has been identified by a genomic approach. It is synthesized predominantly in the submandibular gland and prostate of adult rats in response to androgen steroids and is released locally and systemically in response to stress. We now demonstrate that the cell surface molecule to which sialorphin binds in vivo in the rat kidney is the membrane-anchored neutral endopeptidase (neprilysin; NEP, EC 3.4.24.11). NEP plays an important role in nervous and peripheral tissues, as it turns off several peptide-signaling events at the cell surface. We show that sialorphin prevents spinal and renal NEP from breaking down its two physiologically relevant substrates, substance P and Met-enkephalin in vitro. Sialorphin inhibited the breakdown of substance P with an IC50 of 0.4–1 μM and behaved as a competitive inhibitor. In vivo, i.v. sialorphin elicited potent antinociceptive responses in two behavioral rat models of injury-induced acute and tonic pain, the pin-pain test and formalin test. The analgesia induced by 100–200 μg/kg doses of sialorphin required the activation of μ- and δ-opioid receptors, consistent with the involvement of endogenous opioid receptors in enkephalinergic transmission. We conclude that sialorphin protects endogenous enkephalins released after nociceptive stimuli by inhibiting NEP in vivo. Sialorphin is a natural systemically active regulator of NEP activity. Furthermore, our study provides evidence that it is a physiological modulator of pain perception after injury and might be the progenitor of a new class of therapeutic molecules. PMID:12835417

Sialorphin, a natural inhibitor of rat membrane-bound neutral endopeptidase that displays analgesic activity.

PubMed

Rougeot, Catherine; Messaoudi, Michaël; Hermitte, Véronique; Rigault, Anne Gaëlle; Blisnick, Thierry; Dugave, Christophe; Desor, Didier; Rougeon, François

2003-07-08

Sialorphin is an exocrine and endocrine signaling mediator, which has been identified by a genomic approach. It is synthesized predominantly in the submandibular gland and prostate of adult rats in response to androgen steroids and is released locally and systemically in response to stress. We now demonstrate that the cell surface molecule to which sialorphin binds in vivo in the rat kidney is the membrane-anchored neutral endopeptidase (neprilysin; NEP, EC 3.4.24.11). NEP plays an important role in nervous and peripheral tissues, as it turns off several peptide-signaling events at the cell surface. We show that sialorphin prevents spinal and renal NEP from breaking down its two physiologically relevant substrates, substance P and Met-enkephalin in vitro. Sialorphin inhibited the breakdown of substance P with an IC50 of 0.4-1 microM and behaved as a competitive inhibitor. In vivo, i.v. sialorphin elicited potent antinociceptive responses in two behavioral rat models of injury-induced acute and tonic pain, the pin-pain test and formalin test. The analgesia induced by 100-200 mcicrog/kg doses of sialorphin required the activation of mu- and delta-opioid receptors, consistent with the involvement of endogenous opioid receptors in enkephalinergic transmission. We conclude that sialorphin protects endogenous enkephalins released after nociceptive stimuli by inhibiting NEP in vivo. Sialorphin is a natural systemically active regulator of NEP activity. Furthermore, our study provides evidence that it is a physiological modulator of pain perception after injury and might be the progenitor of a new class of therapeutic molecules.

The tomato mutant ars1 (altered response to salt stress 1) identifies an R1-type MYB transcription factor involved in stomatal closure under salt acclimation.

PubMed

Campos, Juan F; Cara, Beatriz; Pérez-Martín, Fernando; Pineda, Benito; Egea, Isabel; Flores, Francisco B; Fernandez-Garcia, Nieves; Capel, Juan; Moreno, Vicente; Angosto, Trinidad; Lozano, Rafael; Bolarin, Maria C

2016-06-01

A screening under salt stress conditions of a T-DNA mutant collection of tomato (Solanum lycopersicum L.) led to the identification of the altered response to salt stress 1 (ars1) mutant, which showed a salt-sensitive phenotype. Genetic analysis of the ars1 mutation revealed that a single T-DNA insertion in the ARS1 gene was responsible of the mutant phenotype. ARS1 coded for an R1-MYB type transcription factor and its expression was induced by salinity in leaves. The mutant reduced fruit yield under salt acclimation while in the absence of stress the disruption of ARS1 did not affect this agronomic trait. The stomatal behaviour of ars1 mutant leaves induced higher Na(+) accumulation via the transpiration stream, as the decreases of stomatal conductance and transpiration rate induced by salt stress were markedly lower in the mutant plants. Moreover, the mutation affected stomatal closure in a response mediated by abscisic acid (ABA). The characterization of tomato transgenic lines silencing and overexpressing ARS1 corroborates the role of the gene in regulating the water loss via transpiration under salinity. Together, our results show that ARS1 tomato gene contributes to reduce transpirational water loss under salt stress. Finally, this gene could be interesting for tomato molecular breeding, because its manipulation could lead to improved stress tolerance without yield penalty under optimal culture conditions. © 2015 Society for Experimental Biology, Association of Applied Biologists and John Wiley & Sons Ltd.

Glycogen synthase kinase 3 regulates expression of nuclear factor-erythroid-2 related transcription factor-1 (Nrf1) and inhibits pro-survival function of Nrf1

PubMed Central

Biswas, Madhurima; Kwong, Erick K.; Park, Eujean; Nagra, Parminder; Chan, Jefferson Y.

2013-01-01

Nuclear factor E2-related factor-1 (Nrf1) is a basic leucine zipper transcription factor that is known to regulate antioxidant and cytoprotective gene expression. It was recently shown that Nrf1 is regulated by SCF-Fbw7 ubiquitin ligase. However our knowledge of upstream signals that targets Nrf1 for degradation by the UPS is not known. We report here that Nrf1 expression is negatively regulated by glycogen synthase kinase 3 (GSK3) in Fbw7-dependent manner. We show that GSK3 interacts with Nrf1 and phosphorylates the Cdc4 phosphodegron domain (CPD) in Nrf1. Mutation of serine residue in the CPD of Nrf1 to alanine (S350A), blocks Nrf1 from phosphorylation by GSK3, and stabilizes Nrf1. Knockdown of Nrf1 and expression of a constitutively active form of GSK3 results in increased apoptosis in neuronal cells in response to ER stress, while expression of the GSK3 phosphorylation resistant S350A–Nrfl attenuates apoptotic cell death. Together these data suggest that GSK3 regulates Nrf1 expression and cell survival function in response to stress activation. PMID:23623971

Impact of Age and Insulin-Like Growth Factor-1 on DNA Damage Responses in UV-Irradiated Human Skin.

PubMed

Kemp, Michael G; Spandau, Dan F; Travers, Jeffrey B

2017-02-26

The growing incidence of non-melanoma skin cancer (NMSC) necessitates a thorough understanding of its primary risk factors, which include exposure to ultraviolet (UV) wavelengths of sunlight and age. Whereas UV radiation (UVR) has long been known to generate photoproducts in genomic DNA that promote genetic mutations that drive skin carcinogenesis, the mechanism by which age contributes to disease pathogenesis is less understood and has not been sufficiently studied. In this review, we highlight studies that have considered age as a variable in examining DNA damage responses in UV-irradiated skin and then discuss emerging evidence that the reduced production of insulin-like growth factor-1 (IGF-1) by senescent fibroblasts in the dermis of geriatric skin creates an environment that negatively impacts how epidermal keratinocytes respond to UVR-induced DNA damage. In particular, recent data suggest that two principle components of the cellular response to DNA damage, including nucleotide excision repair and DNA damage checkpoint signaling, are both partially defective in keratinocytes with inactive IGF-1 receptors. Overcoming these tumor-promoting conditions in aged skin may therefore provide a way to lower aging-associated skin cancer risk, and thus we will consider how dermal wounding and related clinical interventions may work to rejuvenate the skin, re-activate IGF-1 signaling, and prevent the initiation of NMSC.

Impact of Age and Insulin-Like Growth Factor-1 on DNA Damage Responses in UV-Irradiated Human Skin

PubMed Central

Kemp, Michael G.; Spandau, Dan F; Travers, Jeffrey B.

2017-01-01

The growing incidence of non-melanoma skin cancer (NMSC) necessitates a thorough understanding of its primary risk factors, which include exposure to ultraviolet (UV) wavelengths of sunlight and age. Whereas UV radiation (UVR) has long been known to generate photoproducts in genomic DNA that promote genetic mutations that drive skin carcinogenesis, the mechanism by which age contributes to disease pathogenesis is less understood and has not been sufficiently studied. In this review, we highlight studies that have considered age as a variable in examining DNA damage responses in UV-irradiated skin and then discuss emerging evidence that the reduced production of insulin-like growth factor-1 (IGF-1) by senescent fibroblasts in the dermis of geriatric skin creates an environment that negatively impacts how epidermal keratinocytes respond to UVR-induced DNA damage. In particular, recent data suggest that two principle components of the cellular response to DNA damage, including nucleotide excision repair and DNA damage checkpoint signaling, are both partially defective in keratinocytes with inactive IGF-1 receptors. Overcoming these tumor-promoting conditions in aged skin may therefore provide a way to lower aging-associated skin cancer risk, and thus we will consider how dermal wounding and related clinical interventions may work to rejuvenate the skin, re-activate IGF-1 signaling, and prevent the initiation of NMSC. PMID:28245638

CD10/neutral endopeptidase 24.11 hydrolyzes bombesin-like peptides and regulates the growth of small cell carcinomas of the lung.

PubMed

Shipp, M A; Tarr, G E; Chen, C Y; Switzer, S N; Hersh, L B; Stein, H; Sunday, M E; Reinherz, E L

1991-12-01

Bombesin-like peptides are essential autocrine growth factors for many small cell carcinomas (SCCas) of the lung. Herein, we demonstrate that these malignant pulmonary neuroendocrine cells express low levels of the cell surface metalloendopeptidase CD10/neutral endopeptidase 24.11 (CD10/NEP, common acute lymphoblastic leukemia antigen) and that this enzyme hydrolyzes bombesin-like peptides. The growth of bombesin-like peptide-dependent SCC as is inhibited by CD10/NEP and potentiated by CD10/NEP inhibition. The results provide evidence that CD10/NEP is involved in the regulation of tumor cell proliferation. Since SCCa of the lung occurs almost exclusively in cigarette smokers and cigarette smoke inactivates CD10/NEP, decreased cell surface CD10/NEP enzymatic activity may be causally related to the development of SCCa of the lung.

Proliferation of prostate cancer cells and activity of neutral endopeptidase is regulated by bombesin and IL-1beta with IL-1beta acting as a modulator of cellular differentiation.

PubMed

Albrecht, Martin; Doroszewicz, Jolanta; Gillen, Sonja; Gomes, Iara; Wilhelm, Beate; Stief, Thomas; Aumüller, Gerhard

2004-01-01

Neutral endopeptidase (NEP) is a cell-surface bound enzyme that cleaves and inactivates neuropeptides such as bombesin and substance P and is involved in the transition from hormonally regulated androgen-dependent prostate cancer (PC) to androgen-independent PC. Neuropeptides are implicated in growth regulation of different cell types and function as transmitters between the neuroendocrine and the immune system. NEP-expression, enzymatic activity of the membrane bound protein, cell proliferation, procalcitonin (PCT) production, and secretion as well as changes in cell morphology of prostatic cells were evaluated after treatment with the immunomodulatory cytokine interleukin-1beta (IL-1beta), neuropeptides (bombesin, substance P), and neuropeptide-conditioned media derived from a human neuroendocrine cell line. Incubation of LNCaP tumor cells with IL-1beta resulted in a diminished proliferative activity, induction of neurite-like outgrowth which was accompanied by the formation of tubular-type mitochondria typical for neuronal/neuroendocrine cells, and an increased production and secretion of PCT. Conversely, proliferation of prostatic stromal cells was enhanced by the cytokine coming along with an increased number of Golgi-apparatuses and ER-cisternae. Bombesin had an antimitotic effect on LNCaP, but not on stromal cells. Substance P did not influence the growth of any of the cell types investigated, whereas neuropeptide-conditioned media exerted a slightly mitogenic effect on both cell types. The activity of LNCaP cell-surface bound NEP was enhanced by bombesin, but was diminished by substance P and neuropeptide-conditioned media. Proliferation and activity of neuropeptide degrading NEP is regulated differently by immunomodulatory substances in PC cells and cells derived from the prostatic stroma with IL-1beta being a potent modulator of cellular differentiation and a potential target for anticancer drug design in PC cells. Copyright 2003 Wiley-Liss, Inc.

Neutral endopeptidase promotes phorbol ester-induced apoptosis in prostate cancer cells by inhibiting neuropeptide-induced protein kinase C delta degradation.

PubMed

Sumitomo, M; Shen, R; Goldberg, J S; Dai, J; Navarro, D; Nanus, D M

2000-12-01

Phorbol esters induce apoptosis in androgen-sensitive LNCaP cells, which express neutral endopeptidase (NEP), but not in androgen-independent prostate cancer (PC) cells, which lack NEP expression. We investigated the role of NEP in PC cell susceptibility to 12-O-tetradecanoylphorbol-13-acetate (TPA). Western analysis showed that expression of NEP and protein kinase Cdelta (PKCdelta) correlated with PC cell sensitivity to TPA-induced growth arrest and apoptosis in LNCaP cells and in TSU-Prl cells expressing an inducible wild-type NEP protein. Inhibition of NEP enzyme activity using the specific NEP inhibitor CGS24592, or inhibition of PKCdelta using Rottlerin at concentrations that inhibit PKCdelta but not PKCalpha, significantly inhibited TPA-induced growth inhibition and cell death. Furthermore, pulse-chase experiments showed PKCdelta is stabilized in LNCaP cells and in TSU-Pr1 cells overexpressing wild-type NEP compared with PC cells lacking NEP expression. This results from NEP inactivation of its neuropeptide substrates (bombesin and endothelin-1), which in the absence of NEP stimulate cSrc kinase activity and induce rapid degradation of PKCdelta protein. These results indicate that expression of enzymatically active NEP by PC cells is necessary for TPA-induced apoptosis, and that NEP inhibits neuropeptide-induced, cSrc-mediated PKCdelta degradation.

Suppression of atherosclerotic changes in cholesterol-fed rabbits treated with an oral inhibitor of neutral endopeptidase 24.11 (EC 3.4.24.11).

PubMed

Kugiyama, K; Sugiyama, S; Matsumura, T; Ohta, Y; Doi, H; Yasue, H

1996-08-01

Neutral endopeptidase 24.11 (NEP), widely distributed in the body, hydrolyzes and inactivates a number of endogenous vasoactive peptides, some of which could alter various functions of cells present in the arterial wall. Recently NEP has been found to exist in the vascular endothelium. The aim of this study was to assess the influence of chronic NEP inhibition by daily administration of UK79300 (candoxatril), an orally active NEP inhibitor (NEPI), on the development of atherosclerotic changes in high-cholesterol-fed rabbits. Male New Zealand White rabbits were fed for 8 weeks as follows: normal rabbit diet (Normal, n = 15), 1.5% cholesterol diet (Cholesterol, n = 15), or 1.5% cholesterol diet containing NEPI (20 mg.kg-1.d-1) (Cholesterol+NEPI, n = 15). At the end of the dietary period, NEPI treatment was found to suppress the surface area of the aorta covered by plaques (% surface area: Cholesterol, 59 +/- 6 versus Cholesterol+NEPI, 36 +/- 7, P < .01) and decreased contents of cholesterol and cholesterol esters in the aortas. NEPI also reduced plasma total cholesterol by 27% of Cholesterol rabbits (1781 +/- 130 mg/dL). The endothelial function, estimated by the endothelium-dependent relaxation of the isolated aortas in response to acetylcholine, was preserved in Cholesterol+NEPI rabbits compared with that in Cholesterol rabbits. NEP enzymatic activities in plasma and the particulate fraction of the homogenates from the aortas in Cholesterol rabbits were both increased, 3.1- and 3.9-fold, respectively, above those in Normal rabbits, but the activities in Cholesterol+NEPI rabbits were significantly lower than those in Cholesterol rabbits. UK73967, an active form of UK79300, or phosphoramidon partly reversed the atherosclerotic impairment of relaxation of the isolated thoracic aortic rings from Cholesterol rabbits in response to exogenous additions of C-type natriuretic peptide (CNP) and substance P, which are NEP substrates known to exist endogenously in the vascular

The Role of Neprilysin in Regulating the Hair Cycle

PubMed Central

Morisaki, Naoko; Ohuchi, Atsushi; Moriwaki, Shigeru

2013-01-01

In most mammals, each hair follicle undergoes a cyclic process of growing, regressing and resting phases (anagen, catagen, telogen, respectively) called the hair cycle. Various biological factors have been reported to regulate or to synchronize with the hair cycle. Some factors involved in the extracellular matrix, which is a major component of skin tissue, are also thought to regulate the hair cycle. We have focused on an enzyme that degrades elastin, which is associated with skin elasticity. Since our previous study identified skin fibroblast elastase as neprilysin (NEP), we examined the fluctuation of NEP enzyme activity and its expression during the synchronized hair cycle of rats. NEP activity in the skin was elevated at early anagen, and decreased during catagen to telogen. The expression of NEP mRNA and protein levels was modulated similarly. Immunostaining showed changes in NEP localization throughout the hair cycle, from the follicular epithelium during early anagen to the dermal papilla during catagen. To determine whether NEP plays an important role in regulating the hair cycle, we used a specific inhibitor of NEP (NPLT). NPLT was applied topically daily to the dorsal skin of C3H mice, which had been depilated in advance. Mice treated with NPLT had significantly suppressed hair growth. These data suggest that NEP plays an important role in regulating the hair cycle by its increased expression and activity in the follicular epithelium during early anagen. PMID:23418484

Involvement of interleukin-1 type 1 receptors in lipopolysaccharide-induced sickness responses.

PubMed

Matsuwaki, Takashi; Shionoya, Kiseko; Ihnatko, Robert; Eskilsson, Anna; Kakuta, Shigeru; Dufour, Sylvie; Schwaninger, Markus; Waisman, Ari; Müller, Werner; Pinteaux, Emmanuel; Engblom, David; Blomqvist, Anders

2017-11-01

Sickness responses to lipopolysaccharide (LPS) were examined in mice with deletion of the interleukin (IL)-1 type 1 receptor (IL-1R1). IL-1R1 knockout (KO) mice displayed intact anorexia and HPA-axis activation to intraperitoneally injected LPS (anorexia: 10 or 120µg/kg; HPA-axis: 120µg/kg), but showed attenuated but not extinguished fever (120µg/kg). Brain PGE 2 synthesis was attenuated, but Cox-2 induction remained intact. Neither the tumor necrosis factor-α (TNFα) inhibitor etanercept nor the IL-6 receptor antibody tocilizumab abolished the LPS induced fever in IL-1R1 KO mice. Deletion of IL-1R1 specifically in brain endothelial cells attenuated the LPS induced fever, but only during the late, 3rd phase of fever, whereas deletion of IL-1R1 on neural cells or on peripheral nerves had little or no effect on the febrile response. We conclude that while IL-1 signaling is not critical for LPS induced anorexia or stress hormone release, IL-1R1, expressed on brain endothelial cells, contributes to the febrile response to LPS. However, also in the absence of IL-1R1, LPS evokes a febrile response, although this is attenuated. This remaining fever seems not to be mediated by IL-6 receptors or TNFα, but by some yet unidentified pyrogenic factor. Copyright © 2017 Elsevier Inc. All rights reserved.

High carbon dioxide uptake by subtropical forest ecosystems in the East Asian monsoon region

PubMed Central

Yu, Guirui; Chen, Zhi; Piao, Shilong; Peng, Changhui; Ciais, Philippe; Wang, Qiufeng; Li, Xuanran; Zhu, Xianjin

2014-01-01

Temperate- and high-latitude forests have been shown to contribute a carbon sink in the Northern Hemisphere, but fewer studies have addressed the carbon balance of the subtropical forests. In the present study, we integrated eddy covariance observations established in the 1990s and 2000s to show that East Asian monsoon subtropical forests between 20°N and 40°N represent an average net ecosystem productivity (NEP) of 362 ± 39 g C m−2 yr−1 (mean ± 1 SE). This average forest NEP value is higher than that of Asian tropical and temperate forests and is also higher than that of forests at the same latitudes in Europe–Africa and North America. East Asian monsoon subtropical forests have comparable NEP to that of subtropical forests of the southeastern United States and intensively managed Western European forests. The total NEP of East Asian monsoon subtropical forests was estimated to be 0.72 ± 0.08 Pg C yr−1, which accounts for 8% of the global forest NEP. This result indicates that the role of subtropical forests in the current global carbon cycle cannot be ignored and that the regional distributions of the Northern Hemisphere's terrestrial carbon sinks are needed to be reevaluated. The young stand ages and high nitrogen deposition, coupled with sufficient and synchronous water and heat availability, may be the primary reasons for the high NEP of this region, and further studies are needed to quantify the contribution of each underlying factor. PMID:24639529

A Negative-Feedback Loop between the Detoxification/Antioxidant Response Factor SKN-1 and Its Repressor WDR-23 Matches Organism Needs with Environmental Conditions

PubMed Central

Leung, Chi K.; Wang, Ying; Deonarine, Andrew; Tang, Lanlan; Prasse, Stephanie

2013-01-01

Negative-feedback loops between transcription factors and repressors in responses to xenobiotics, oxidants, heat, hypoxia, DNA damage, and infection have been described. Although common, the function of feedback is largely unstudied. Here, we define a negative-feedback loop between the Caenorhabditis elegans detoxification/antioxidant response factor SKN-1/Nrf and its repressor wdr-23 and investigate its function in vivo. Although SKN-1 promotes stress resistance and longevity, we find that tight regulation by WDR-23 is essential for growth and reproduction. By disabling SKN-1 transactivation of wdr-23, we reveal that feedback is required to set the balance between growth/reproduction and stress resistance/longevity. We also find that feedback is required to set the sensitivity of a core SKN-1 target gene to an electrophile. Interestingly, the effect of feedback on target gene induction is greatly reduced when the stress response is strongly activated, presumably to ensure maximum activation of cytoprotective genes during potentially fatal conditions. Our work provides a framework for understanding the function of negative feedback in inducible stress responses and demonstrates that manipulation of feedback alone can shift the balance of competing animal processes toward cell protection, health, and longevity. PMID:23836880

Thy-1 Expression Regulates the Ability of Rat Lung Fibroblasts to Activate Transforming Growth Factor-β in Response to Fibrogenic Stimuli

PubMed Central

Zhou, Yong; Hagood, James S.; Murphy-Ullrich, Joanne E.

2004-01-01

Distinct subpopulations of fibroblasts contribute to lung fibrosis, although the mechanisms underlying fibrogenesis in these subpopulations are not clear. Differential expression of the glycophosphatidylinositol-linked protein Thy-1 affects proliferation and myofibroblast differentiation. Lung fibroblast populations selected on the basis of Thy-1 expression by cell sorting were examined for responses to fibrogenic stimuli. Thy-1 (−) and Thy-1 (+) fibroblast populations were treated with platelet-derived growth factor-BB, interleukin-1β, interleukin-4, or bleomycin and assessed for activation of transforming growth factor (TGF)-β, Smad3 phosphorylation, and α-smooth muscle actin and fibronectin expression. Thy-1 (−) fibroblasts responded to these stimuli with increased TGF-β activity, Smad3 phosphorylation, and expression of α-smooth muscle actin and fibronectin, whereas Thy-1 (+) fibroblasts resisted stimulation. The unresponsiveness of Thy-1 (+) cells is not because of defective TGF-β signaling because both subsets respond to exogenous active TGF-β. Rather, Thy-1 (−) fibroblasts activate latent TGF-β in response to fibrogenic stimuli, whereas Thy-1 (+) cells fail to do so. Defective activation is common to multiple mechanisms of TGF-β activation, including thrombospondin 1, matrix metalloproteinase, or plasmin. Thy-1 (−) lung fibroblasts transfected with Thy-1 also become resistant to fibrogenic stimulation, indicating that Thy-1 is a critical biological response modifier that protects against fibrotic progression by controlling TGF-β activation. These studies provide a molecular basis for understanding the differential roles of fibroblast subpopulations in fibrotic lung disease through control of latent TGF-β activation. PMID:15277239

Landslides, floods and sinkholes in a karst environment: the 1-6 September 2014 Gargano event, southern Italy

NASA Astrophysics Data System (ADS)

Martinotti, Maria Elena; Pisano, Luca; Marchesini, Ivan; Rossi, Mauro; Peruccacci, Silvia; Brunetti, Maria Teresa; Melillo, Massimo; Amoruso, Giuseppe; Loiacono, Pierluigi; Vennari, Carmela; Vessia, Giovanna; Trabace, Maria; Parise, Mario; Guzzetti, Fausto

2017-03-01

In karst environments, heavy rainfall is known to cause multiple geohydrological hazards, including inundations, flash floods, landslides and sinkholes. We studied a period of intense rainfall from 1 to 6 September 2014 in the Gargano Promontory, a karst area in Puglia, southern Italy. In the period, a sequence of torrential rainfall events caused severe damage and claimed two fatalities. The amount and accuracy of the geographical and temporal information varied for the different hazards. The temporal information was most accurate for the inundation caused by a major river, less accurate for flash floods caused by minor torrents and even less accurate for landslides. For sinkholes, only generic information on the period of occurrence of the failures was available. Our analysis revealed that in the promontory, rainfall-driven hazards occurred in response to extreme meteorological conditions and that the karst landscape responded to the torrential rainfall with a threshold behaviour. We exploited the rainfall and the landslide information to design the new ensemble-non-exceedance probability (E-NEP) algorithm for the quantitative evaluation of the possible occurrence of rainfall-induced landslides and of related geohydrological hazards. The ensemble of the metrics produced by the E-NEP algorithm provided better diagnostics than the single metrics often used for landslide forecasting, including rainfall duration, cumulated rainfall and rainfall intensity. We expect that the E-NEP algorithm will be useful for landslide early warning in karst areas and in other similar environments. We acknowledge that further tests are needed to evaluate the algorithm in different meteorological, geological and physiographical settings.

Characterization of available light for seagrass and patch reef productivity in Sugarloaf Key, Lower Florida Keys

USGS Publications Warehouse

Toro-Farmer, Gerardo; Muller-Karger, Frank E.; Vega-Rodriguez, Maria; Melo, Nelson; Yates, Kimberly K.; Johns, Elizabeth; Cerdeira-Estrada, Sergio; Herwitz, Stan R.

2016-01-01

Light availability is an important factor driving primary productivity in benthic ecosystems, but in situ and remote sensing measurements of light quality are limited for coral reefs and seagrass beds. We evaluated the productivity responses of a patch reef and a seagrass site in the Lower Florida Keys to ambient light availability and spectral quality. In situ optical properties were characterized utilizing moored and water column bio-optical and hydrographic measurements. Net ecosystem productivity (NEP) was also estimated for these study sites using benthic productivity chambers. Our results show higher spectral light attenuation and absorption, and lower irradiance during low tide in the patch reef, tracking the influx of materials from shallower coastal areas. In contrast, the intrusion of clearer surface Atlantic Ocean water caused lower values of spectral attenuation and absorption, and higher irradiance in the patch reef during high tide. Storms during the studied period, with winds >10 m·s−1, caused higher spectral attenuation values. A spatial gradient of NEP was observed, from high productivity in the shallow seagrass area, to lower productivity in deeper patch reefs. The highest daytime NEP was observed in the seagrass, with values of almost 0.4 g·O2·m−2·h−1. Productivity at the patch reef area was lower in May than during October 2012 (mean = 0.137 and 0.177 g·O2·m−2·h−1, respectively). Higher photosynthetic active radiation (PAR) levels measured above water and lower light attenuation in the red region of the visible spectrum (~666 to ~699 nm) had a positive correlation with NEP. Our results indicate that changes in light availability and quality by suspended or resuspended particles limit benthic productivity in the Florida Keys.

Impact of genetic factors (VKORC1, CYP2C9, CYP4F2 and EPHX1) on the anticoagulation response to fluindione

PubMed Central

Lacut, Karine; Ayme-Dietrich, Estelle; Gourhant, Lenaick; Poulhazan, Elise; Andro, Marion; Becquemont, Laurent; Mottier, Dominique; Le Gal, Gregoire; Verstuyft, Celine

2012-01-01

AIM Genetic variants of the enzyme that metabolizes warfarin, cytochrome P-450 2C9 (CYP2C9) and of a key pharmacologic target of vitamin K antagonists, vitamin K epoxide reductase (VKORC1), contribute to differences in patients' responses to coumarin derivatives. The role of these variants in fluindione response is unknown. Our aim was to assess whether genetic factors contribute to the variability in the response to fluindione. METHODS Four hundred sixty-five patients with a venous thromboembolic event treated by fluindione for at least 3 months with a target international normalized ratio (INR) of 2.0 to 3.0 were studied. VKORC1, CYP2C9, CYP4F2 and EPHX1 genotypes were assessed. INR checks, fluindione doses and bleeding events were collected. RESULTS VKORC1 genotype had a significant impact on early anticoagulation (INR value ≥2 after the first two intakes) (P < 0.0001), on the time required to reach a first INR within the therapeutic range (P < 0.0001) and on the time to obtain a first INR value > 4 (P = 0.0002). The average daily dose of fluindione during the first period of stability was significantly associated with the VKORC1 genotype: 19.8 mg (±5.5) for VKORC1 CC, 14.7 mg (±6.2) for VKORC1 CT and 8.2 mg (±2.5) for VKORC1 TT (P < 0.0001). CYP2C9, CYP4F2 and EPHX1 genotypes did not significantly influence the response to fluindione. CONCLUSIONS VKORC1 genotype strongly affected anticoagulation induced by fluindione whereas CYP2C9, CYP4F2 and EPHX1 genotypes seemed less determining. PMID:21883387

The Yeast Forkhead Transcription Factors Fkh1 and Fkh2 Regulate Lifespan and Stress Response Together with the Anaphase-Promoting Complex

PubMed Central

Postnikoff, Spike D. L.; Malo, Mackenzie E.; Wong, Berchman; Harkness, Troy A. A.

2012-01-01

Forkhead box O (FOXO) transcription factors have a conserved function in regulating metazoan lifespan. A key function in this process involves the regulation of the cell cycle and stress responses including free radical scavenging. We employed yeast chronological and replicative lifespan assays, as well as oxidative stress assays, to explore the potential evolutionary conservation of function between the FOXOs and the yeast forkhead box transcription factors FKH1 and FKH2. We report that the deletion of both FKH genes impedes normal lifespan and stress resistance, particularly in stationary phase cells, which are non-responsive to caloric restriction. Conversely, increased expression of the FKHs leads to extended lifespan and improved stress response. Here we show the Anaphase-Promoting Complex (APC) genetically interacts with the Fkh pathway, likely working in a linear pathway under normal conditions, as fkh1Δ fkh2Δ post-mitotic survival is epistatic to that observed in apc5CA mutants. However, under stress conditions, post-mitotic survival is dramatically impaired in apc5CA fkh1Δ fkh2Δ, while increased expression of either FKH rescues APC mutant growth defects. This study establishes the FKHs role as evolutionarily conserved regulators of lifespan in yeast and identifies the APC as a novel component of this mechanism under certain conditions, likely through combined regulation of stress response, genomic stability, and cell cycle regulation. PMID:22438832

Expression of early growth response factor-1 in rats with cerulein-induced acute pancreatitis and its significance

PubMed Central

Gong, Lan-Bo; He, Li; Liu, Yang; Chen, Xue-Qing; Jiang, Bo

2005-01-01

AIM: To observe the expressions of early growth response factor-1 (Egr-1) and tissue factor (TF) in rats with cerulein-induced acute pancreatitis and to explore its significance. METHODS: A large dose of cerulein was used to create the experimental acute pancreatitis model in rats. The changes of Egr-1 mRNA and protein in rats were observed during 30 min to 4 h after the treatment and immunohistochemical method was used to observe the localized expression of Egr-1 in tissues. In addition to the mRNA expression of Egr-1 target gene, TF was also observed. A blank control group, and a bombesin-administered group were used for comparison. RESULTS: After the stimulation of a large dose of cerulein, the rats showed typical inflammatory changes of acute pancreatitis. Thirty minutes after the stimulation, the mRNA expression of Egr-1 in the pancreatic tissue reached its peak and then declined, while the expression of Egr-1 protein reached its peak 2 h after the stimulation. Histologically, 2 h after the stimulation, almost all pancreatic acinar cells had the expression of Egr-1 protein, which was focused in the nuclei. The mRNA expression of TF occurred 1 h after the stimulation and gradually increased within 4 h. However, a large dose of bombesin only stimulated the pancreatic tissue to produce a little mRNA expression of Egr-1 and no mRNA expression of Egr-1 protein and TF. CONCLUSION: Egr-1 as a pro-inflammatory transcription factor may play an important role in the pathogenesis of acute pancreatitis by modulating the expression of TF. PMID:16124058

Hypoxia-inducible factor-1α promotes cell survival during ammonia stress response in ovarian cancer stem-like cells

PubMed Central

Kitajima, Shojiro; Lee, Kian Leong; Hikasa, Hiroki; Sun, Wendi; Huang, Ruby Yun-Ju; Yang, Henry; Matsunaga, Shinji; Yamaguchi, Takehiro; Araki, Marito; Kato, Hiroyuki

2017-01-01

Ammonia is a toxic by-product of metabolism that causes cellular stresses. Although a number of proteins are involved in adaptive stress response, specific factors that counteract ammonia-induced cellular stress and regulate cell metabolism to survive against its toxicity have yet to be identified. We demonstrated that the hypoxia-inducible factor-1α (HIF-1α) is stabilized and activated by ammonia stress. HIF-1α activated by ammonium chloride compromises ammonia-induced apoptosis. Furthermore, we identified glutamine synthetase (GS) as a key driver of cancer cell proliferation under ammonia stress and glutamine-dependent metabolism in ovarian cancer stem-like cells expressing CD90. Interestingly, activated HIF-1α counteracts glutamine synthetase function in glutamine metabolism by facilitating glycolysis and elevating glucose dependency. Our studies reveal the hitherto unknown functions of HIF-1α in a biphasic ammonia stress management in the cancer stem-like cells where GS facilitates cell proliferation and HIF-1α contributes to the metabolic remodeling in energy fuel usage resulting in attenuated proliferation but conversely promoting cell survival. PMID:29383096

CD10/neutral endopeptidase 24.11 hydrolyzes bombesin-like peptides and regulates the growth of small cell carcinomas of the lung.

PubMed Central

Shipp, M A; Tarr, G E; Chen, C Y; Switzer, S N; Hersh, L B; Stein, H; Sunday, M E; Reinherz, E L

1991-01-01

Bombesin-like peptides are essential autocrine growth factors for many small cell carcinomas (SCCas) of the lung. Herein, we demonstrate that these malignant pulmonary neuroendocrine cells express low levels of the cell surface metalloendopeptidase CD10/neutral endopeptidase 24.11 (CD10/NEP, common acute lymphoblastic leukemia antigen) and that this enzyme hydrolyzes bombesin-like peptides. The growth of bombesin-like peptide-dependent SCC as is inhibited by CD10/NEP and potentiated by CD10/NEP inhibition. The results provide evidence that CD10/NEP is involved in the regulation of tumor cell proliferation. Since SCCa of the lung occurs almost exclusively in cigarette smokers and cigarette smoke inactivates CD10/NEP, decreased cell surface CD10/NEP enzymatic activity may be causally related to the development of SCCa of the lung. Images PMID:1660144

Formononetin accelerates wound repair by the regulation of early growth response factor-1 transcription factor through the phosphorylation of the ERK and p38 MAPK pathways.

PubMed

Huh, Jeong-Eun; Nam, Dong-Woo; Baek, Young-Hyun; Kang, Jung Won; Park, Dong-Suk; Choi, Do-Young; Lee, Jae-Dong

2011-01-01

Formononetin, a phytoestrogen from the root of Astragalus membranaceus, is used as a blood enhancer and to improve blood microcirculation in complementary and alternative medicine. The present study investigated the influence of formononetin on the expression of early growth response factor-1 (Egr-1) and growth factors contributing to wound healing. Formononetin significantly increased growth factors such as transforming growth factor-beta 1 (TGF-β1), vascular endothelial growth factor (VEGF), platelet-derived growth factor (PDGF) and basic fibroblast growth factor (bFGF) in human umbilical vein endothelial cells (HUVECs). Formononetin also increased the expression of Egr-1 transcription factor by 3.2- and 10.5-fold, compared with recombinant VEGF(125) in HUVECs. The formononetin-mediated 12%-43% increase induced endothelial cell proliferation and recovered the migration of wounded HUVECs. In an ex vivo angiogenesis assay, formononetin produced a larger capillary sprouting area than produced using recombinant VEGF(125). Cell proliferation and migration of HUVECs were also greater in the presence of formonectin than VEGF(125). Western blot analysis of scratch-wounded confluent HUVECs showed that formononetin induced the phosphorylation of extracellular signal-regulated kinase (ERK) and slightly inhibited the phosphorylation of p38 mitogen-activated protein kinase (MAPK). The formononetin-mediated sustained activation of Egr-1 was suppressed by the ERK inhibitor PD98059 and the p38 inhibitor SB203580. PD98059 inhibited the formononetin-induced endothelial proliferation and repair in scratch-wounded HUVECs, SB203580 increased the cell proliferation and wound healing. Formononetin accelerate wound closure rate as early as day 3 after surgery and consistently observed until day 10 after in wound animal model. These data suggest that formononetin promotes endothelial repair and wound healing in a process involving the over-expression of Egr-1 transcription factor

Chronic intermittent hypoxia induces changes on the expression and activity of neprilysin (EC 3.4.24.11) in the brain of rats.

PubMed

de Oliveira, Renato W; Julian, Guilherme S; Perry, Juliana C; Tufik, Sergio; Chagas, Jair R

2018-06-21

Obstructive sleep apnea (OSA) is a frequent sleeping breathing disorder associated with cognitive impairments. Neprilysin (NEP) is responsible for degrading several substrates related to cognition; however, the effect of chronic intermittent hypoxia (CIH) on NEP is still unknown. This study aimed to evaluate the expression and activity of NEP in cognitive-related brain structures of rats submitted to CIH. Western blot, qRT-PCR and enzyme activity assay, demonstrated that a six-week intermittent hypoxia increased NEP expression and activity, selectively in temporal cortex, but not in the hippocampus and frontal cortex. The increase in NEP activity and expression was reverted followed by two weeks recovery in normoxia. These data show that CIH protocol increases the expression and activity of NEP selectively in the temporal cortex. Additional mechanisms must be investigated to elucidate the effects of CIH in cognition. Copyright © 2018 Elsevier B.V. All rights reserved.

Characterization of StABF1, a stress-responsive bZIP transcription factor from Solanum tuberosum L. that is phosphorylated by StCDPK2 in vitro.

PubMed

Muñiz García, María Noelia; Giammaria, Verónica; Grandellis, Carolina; Téllez-Iñón, María Teresa; Ulloa, Rita María; Capiati, Daniela Andrea

2012-04-01

ABF/AREB bZIP transcription factors mediate plant abiotic stress responses by regulating the expression of stress-related genes. These proteins bind to the abscisic acid (ABA)-responsive element (ABRE), which is the major cis-acting regulatory sequence in ABA-dependent gene expression. In an effort to understand the molecular mechanisms of abiotic stress resistance in cultivated potato (Solanum tuberosum L.), we have cloned and characterized an ABF/AREB-like transcription factor from potato, named StABF1. The predicted protein shares 45-57% identity with A. thaliana ABFs proteins and 96% identity with the S. lycopersicum SlAREB1 and presents all of the distinctive features of ABF/AREB transcription factors. Furthermore, StABF1 is able to bind to the ABRE in vitro. StABF1 gene is induced in response to ABA, drought, salt stress and cold, suggesting that it might be a key regulator of ABA-dependent stress signaling pathways in cultivated potato. StABF1 is phosphorylated in response to ABA and salt stress in a calcium-dependent manner, and we have identified a potato CDPK isoform (StCDPK2) that phosphorylates StABF1 in vitro. Interestingly, StABF1 expression is increased during tuber development and by tuber-inducing conditions (high sucrose/nitrogen ratio) in leaves. We also found that StABF1 calcium-dependent phosphorylation is stimulated by tuber-inducing conditions and inhibited by gibberellic acid, which inhibits tuberization.

Cardiac tissue enriched factors serum response factor and GATA-4 are mutual coregulators

NASA Technical Reports Server (NTRS)

Belaguli, N. S.; Sepulveda, J. L.; Nigam, V.; Charron, F.; Nemer, M.; Schwartz, R. J.

2000-01-01

Combinatorial interaction among cardiac tissue-restricted enriched transcription factors may facilitate the expression of cardiac tissue-restricted genes. Here we show that the MADS box factor serum response factor (SRF) cooperates with the zinc finger protein GATA-4 to synergistically activate numerous myogenic and nonmyogenic serum response element (SRE)-dependent promoters in CV1 fibroblasts. In the absence of GATA binding sites, synergistic activation depends on binding of SRF to the proximal CArG box sequence in the cardiac and skeletal alpha-actin promoter. GATA-4's C-terminal activation domain is obligatory for synergistic coactivation with SRF, and its N-terminal domain and first zinc finger are inhibitory. SRF and GATA-4 physically associate both in vivo and in vitro through their MADS box and the second zinc finger domains as determined by protein A pullout assays and by in vivo one-hybrid transfection assays using Gal4 fusion proteins. Other cardiovascular tissue-restricted GATA factors, such as GATA-5 and GATA-6, were equivalent to GATA-4 in coactivating SRE-dependent targets. Thus, interaction between the MADS box and C4 zinc finger proteins, a novel regulatory paradigm, mediates activation of SRF-dependent gene expression.

The Transcription Factor BcLTF1 Regulates Virulence and Light Responses in the Necrotrophic Plant Pathogen Botrytis cinerea

PubMed Central

Schumacher, Julia; Simon, Adeline; Cohrs, Kim Christopher; Viaud, Muriel; Tudzynski, Paul

2014-01-01

Botrytis cinerea is the causal agent of gray mold diseases in a range of dicotyledonous plant species. The fungus can reproduce asexually by forming macroconidia for dispersal and sclerotia for survival; the latter also participate in sexual reproduction by bearing the apothecia after fertilization by microconidia. Light induces the differentiation of conidia and apothecia, while sclerotia are exclusively formed in the absence of light. The relevance of light for virulence of the fungus is not obvious, but infections are observed under natural illumination as well as in constant darkness. By a random mutagenesis approach, we identified a novel virulence-related gene encoding a GATA transcription factor (BcLTF1 for light-responsive TF1) with characterized homologues in Aspergillus nidulans (NsdD) and Neurospora crassa (SUB-1). By deletion and over-expression of bcltf1, we confirmed the predicted role of the transcription factor in virulence, and discovered furthermore its functions in regulation of light-dependent differentiation, the equilibrium between production and scavenging of reactive oxygen species (ROS), and secondary metabolism. Microarray analyses revealed 293 light-responsive genes, and that the expression levels of the majority of these genes (66%) are modulated by BcLTF1. In addition, the deletion of bcltf1 affects the expression of 1,539 genes irrespective of the light conditions, including the overexpression of known and so far uncharacterized secondary metabolism-related genes. Increased expression of genes encoding alternative respiration enzymes, such as the alternative oxidase (AOX), suggest a mitochondrial dysfunction in the absence of bcltf1. The hypersensitivity of Δbctlf1 mutants to exogenously applied oxidative stress - even in the absence of light - and the restoration of virulence and growth rates in continuous light by antioxidants, indicate that BcLTF1 is required to cope with oxidative stress that is caused either by exposure to light

Hypoxia inducible factor 1 (HIF-1) and cardioprotection

PubMed Central

Tekin, Demet; Dursun, Ali D; Xi, Lei

2010-01-01

Since its discovery in early 1990s, hypoxia inducible factor 1 (HIF-1) has been increasingly recognized for its key role in transcriptional control of more than a hundred genes that regulate a wide-spectrum of cellular functional events, including angiogenesis, vasomotor control, glucose and energy metabolism, erythropoiesis, iron homeostasis, pH regulation, cell proliferation and viability. Evidence accumulated during the past 7 years suggests a critical role for HIF-1α in mediating cardioprotection. The purpose of our present article is to provide an updated overview on this important regulator of gene expression in the cellular stress-responsive and adaptive process. We have particularly emphasized the involvement of HIF-1 in the induction of cardioprotective molecules, such as inducible nitric oxide synthase (iNOS), hemeoxygenase 1 (HO-1), and erythropoietin (EPO), which in turn alleviate myocardial damages caused by harmful events such as ischemia-reperfusion injury. Despite these advances, further in-depth studies are needed to elucidate the possible coordination or interaction between HIF-1α and other key transcription factors in regulating protein expression that leads to cardioprotection. PMID:20711226

Inhibitors of neutral endopeptidase potentiate electrically and capsaicin-induced noncholinergic contraction in guinea pig bronchi.

PubMed

Djokic, T D; Nadel, J A; Dusser, D J; Sekizawa, K; Graf, P D; Borson, D B

1989-01-01

To evaluate the role of airway neutral endopeptidase (NEP) in the regulation of contraction of airway smooth muscle in response to endogenous tachykinins, we studied the effects of the NEP inhibitor phosphoramidon on contractions of guinea pig bronchial smooth muscle strips induced by either electrical field stimulation (EFS) or by capsaicin. In the presence of atropine (10(-6) M), propranolol (10(-6) M), phentolamine (10(-5) M), indomethacin (10(-6) M) and pyrilamine (5 x 10(-6) M) EFS (biphasic; pulse width, 1.0 msec; frequency 0.5-5 Hz for 30 sec; intensity, 20 V) produced noncholinergic, nonadrenergic muscle contraction in a frequency-dependent fashion (P less than .001). Phosphoramidon potentiated the contractile responses to EFS (P less than .01). Leucine-thiorphan (10(-5) M), another NEP inhibitor, potentiated EFS-induced contraction in a similar fashion as phosphoramidon (186 and 182% of control, respectively; each comparison, P less than .025). Captopril, bestatin, leupeptin and physostigmine (each drug, 10(-5) M) were without effect (P greater than .5, N = 5). Capsaicin (1.5 x 10(-8) M) produced long-lasting atropine-resistant smooth muscle contraction, an effect potentiated by phosphoramidon (10(-5) M (P less than .001). Removal of the epithelium slightly but significantly (P less than .05) increased the contractile responses to capsaicin and to EFS at impulse frequencies of 2 and 5 Hz, and phosphoramidon substantially increased contractions in tissues without epithelium. The trachea, bronchi and lungs each contained significant NEP activity.(ABSTRACT TRUNCATED AT 250 WORDS)

Ethylene response factor AtERF72 negatively regulates Arabidopsis thaliana response to iron deficiency.

PubMed

Liu, Wei; Li, Qiwei; Wang, Yi; Wu, Ting; Yang, Yafei; Zhang, Xinzhong; Han, Zhenhai; Xu, Xuefeng

2017-09-23

Ethylene regulates the plant's response to stress caused by iron (Fe) deficiency. However, specific roles of ERF proteins in response to Fe deficiency remain poorly understood. Here, we investigated the role of ERF72 in response to iron deficiency in Arabidopsis thaliana. In this study, the levels of the ethylene response factor AtERF72 increased in leaves and roots induced under the iron deficient conditions. erf72 mutant plants showed increased growth compared to wild type (WT) when grown in iron deficient medium for 5 d. erf72 mutants had increased root H + velocity and the ferric reductase activity, and increase in the expression of the iron deficiency response genes iron-regulated transporter 1 (IRT1) and H + -ATPase (HA2) levels in iron deficient conditions. Compared to WT plants, erf72 mutants retained healthy chloroplast structure with significantly higher Fe and Mg content, and decreased chlorophyll degradation gene pheophorbide a oxygenase (PAO) and chlorophyllase (CLH1) expression when grown in iron deficient media. Yeast one-hybrid analysis showed that ERF72 could directly bind to the promoter regions of iron deficiency responses genes IRT1, HA2 and CLH1. Based on our results, we suggest that ethylene released from plants under iron deficiency stress can activate the expression of ERF72, which responds to iron deficiency in the negative regulation. Copyright © 2017 Elsevier Inc. All rights reserved.

Growth hormone-insulin-like growth factor-1 and inflammatory response to a single exercise bout in children and adolescents.

PubMed

Nemet, Dan; Eliakim, Alon

2010-01-01

Physical activity plays an important role in tissue anabolism, growth and development, but the mechanisms that link patterns of exercise with tissue anabolism are not completely understood. The effectiveness of physical training depends on the training load and on the individual ability to tolerate it, and an imbalance between the two may lead to under or over-training. Therefore, many efforts have been made to find objective parameters to quantify the balance between training load and the athlete's tolerance. One of the unique features of exercise is that it leads to a simultaneous increase of antagonistic mediators. On the one hand, exercise stimulates anabolic components of the growth hormone (GH) → IGF-1 (insulin-like growth factor-1) axis. On the other hand, exercise elevates catabolic pro-inflammatory cytokines such as interleukin-6 (IL-6), IL-1 and tumor necrosis factor-α (TNF-α). This emphasizes probably the importance of optimal adaptation to exercise in particularly during adolescence. The very fine balance between the anabolic and inflammatory/catabolic response to exercise will determine the effectiveness of exercise training and the health consequences of exercise. If the anabolic response is stronger, exercise will probably lead ultimately to increased muscle mass and improved fitness. A greater catabolic response, in particularly if persists for long duration, may lead to overtraining. Therefore, changes in the anabolic-catabolic hormonal balance and in circulating inflammatory cytokines can be used by adolescent athletes and/or their coaches to gauge the training intensity in individual and team sports. Copyright © 2010 S. Karger AG, Basel.

Kruppel-like factor 2 inhibits hypoxia-inducible factor 1alpha expression and function in the endothelium.

PubMed

Kawanami, Daiji; Mahabeleshwar, Ganapati H; Lin, Zhiyong; Atkins, G Brandon; Hamik, Anne; Haldar, Saptarsi M; Maemura, Koji; Lamanna, Joseph C; Jain, Mukesh K

2009-07-31

Hypoxia-inducible factor 1 (HIF-1) is a central regulator of the hypoxic response in many cell types. In endothelial cells, HIF-1 induces the expression of key proangiogenic factors to promote angiogenesis. Recent studies have identified Kruppel-like factor 2 (KLF2) as a potent inhibitor of angiogenesis. However, the role of KLF2 in regulating HIF-1 expression and function has not been evaluated. KLF2 expression was induced acutely by hypoxia in endothelial cells. Adenoviral overexpression of KLF2 inhibited hypoxia-induced expression of HIF-1alpha and its target genes such as interleukin 8, angiopoietin-2, and vascular endothelial growth factor in endothelial cells. Conversely, knockdown of KLF2 increased expression of HIF-1alpha and its targets. Furthermore, KLF2 inhibited hypoxia-induced endothelial tube formation, whereas endothelial cells from mice with haploinsufficiency of KLF2 showed increased tube formation in response to hypoxia. Consistent with this ex vivo observation, KLF2 heterozygous mice showed increased microvessel density in the brain. Mechanistically, KLF2 promoted HIF-1alpha degradation in a von Hippel-Lindau protein-independent but proteasome-dependent manner. Finally, KLF2 disrupted the interaction between HIF-1alpha and its chaperone Hsp90, suggesting that KLF2 promotes degradation of HIF-1alpha by affecting its folding and maturation. These observations identify KLF2 as a novel inhibitor of HIF-1alpha expression and function. Therefore, KLF2 may be a target for modulating the angiogenic response in disease states.

Inhibition of CRM1-mediated nuclear export of influenza A nucleoprotein and nuclear export protein as a novel target for antiviral drug development

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chutiwitoonchai, Nopporn; Mano, Takafumi; Kakisaka

An anti-influenza compound, DP2392-E10 based on inhibition of the nuclear export function of the viral nucleoprotein-nuclear export signal 3 (NP-NES3) domain was successfully identified by our previous high-throughput screening system. Here, we demonstrated that DP2392-E10 exerts its antiviral effect by inhibiting replication of a broad range of influenza A subtypes. In regard to the molecular mechanism, we revealed that DP2392-E10 inhibits nuclear export of both viral NP and nuclear export protein (NEP). More specifically, in vitro pull-down assays revealed that DP2392-E10 directly binds cellular CRM1, which mediates nuclear export of NP and NEP. In silico docking suggested that DP2392-E10 bindsmore » at a region close to the HEAT9 and HEAT10 domains of CRM1. Together, these results indicate that the CRM1-mediated nuclear export function of influenza virus represents a new potential target for antiviral drug development, and also provide a core structure for a novel class of inhibitors that target this function. - Highlights: •DP2392-E10 inhibits replication of a broad range of influenza A subtypes. •DP2392-E10 inhibits nuclear exports of NP and NEP via their NP-NES3 and NEP-NES2 domains, respectively. •DP2392-E10 is predicted to directly bind CRM1 in the region near the HEAT9 and HEAT10 repeats.« less

Responsivity boosting in FIR TiN LEKIDs using phonon recycling: simulations and array design

NASA Astrophysics Data System (ADS)

Fyhrie, Adalyn; McKenney, Christopher; Glenn, Jason; LeDuc, Henry G.; Gao, Jiansong; Day, Peter; Zmuidzinas, Jonas

2016-07-01

To characterize further the cosmic star formation history at high redshifts, a large-area survey by a cryogenic 4-6 meter class telescope with a focal plane populated by tens of thousands of far-infrared (FIR, 30-300 μm) detectors with broadband detector noise equivalent powers (NEPs) on the order of 3×10-9 W/√ Hz is needed. Ideal detectors for such a surveyor do not yet exist. As a demonstration of one technique for approaching the ultra-low NEPs required by this surveyor, we present the design of an array of 96 350 µm KIDs that utilize phonon recycling to boost responsivity. Our KID array is fabricated with TiN deposited on a silicon-on-insulator (SOI) wafer, which is a 2 μm thick layer of silicon bonded to a thicker slab of silicon by a thin oxide layer. The backside thick slab is etched away underneath the absorbers so that the inductors are suspended on just the 2 μm membrane. The intent is that quasiparticle recombination phonons are trapped in the thin membrane, thereby increasing their likelihood of being re-absorbed by the KID to break additional Cooper pairs and boost responsivity. We also present a Monte-Carlo simulation that predicts the amount of signal boost expected from phonon recycling given different detector geometries and illumination strategies. For our current array geometry, the simulation predicts a measurable 50% boost in responsivity.

Isolation and molecular characterization of a novel WIN1/SHN1 ethylene-responsive transcription factor TdSHN1 from durum wheat (Triticum turgidum. L. subsp. durum).

PubMed

Djemal, Rania; Khoudi, Habib

2015-11-01

Over the last decade, APETALA2/Ethylene Responsive Factor (AP2/ERF) proteins have become the subject of intensive research activity due to their involvement in a variety of biological processes. This research led to the identification of AP2/ERF genes in many species; however, little is known about these genes in durum wheat, one of the most important cereal crops in the world. In this study, a new member of the AP2/ERF transcription factor family, designated TdSHN1, was isolated from durum wheat using thermal asymetric interlaced PCR (TAIL-PCR) method. Protein sequence analysis showed that TdSHN1 contained an AP2/ERF domain of 63 amino acids and a putative nuclear localization signal (NLS). Phylogenetic analysis showed that TdSHN1 belongs to a group Va protein in the ERF subfamily which contains the Arabidopsis ERF proteins (SHN1, SHN2, and SHN3). Expression of TdSHN1 was strongly induced by salt, drought, abscisic acid (ABA), and cold. In planta, TdSHN1 protein was able to activate the transcription of GUS reporter gene driven by the GCC box and DRE element sequences. In addition, TdSHN1 was targeted to the nucleus when transiently expressed in tobacco epidermal cells. In transgenic yeast, overexpression of TdSHN1 increased tolerance to multiple abiotic stresses. Taken together, the results showed that TdSHN1 encodes an abiotic stress-inducible, transcription factor which confers abiotic stress tolerance in yeast. TdSHN1 is therefore a promising candidate for improvement of biotic and abiotic stress tolerance in wheat as well as other crops.

Development of Fast, Background-Limited Transition-Edge Sensors for the Background-Limited Infrared/Sub-mm Spectrograph (BLISS) for SPICA

NASA Technical Reports Server (NTRS)

Beyer, Andrew D.; Runyan, M. C.; Kenyon, M.; Echternach, P. M .; Chui, T.; Bumble, B.; Bradford, C. M.; Holmes, W. A.; Bock, J. J.

2012-01-01

We report experimental progress toward demonstrating background-limited arrays of membrane-isolated transition-edge sensors (TESs) for the Background Limited Infrared/Sub-mm Spectrograph (BLISS). BLISS is a space-borne instrument with grating spectrometers for wavelengths lambda=35-435 micron and with R=lambda/delta lambda approximately equals 500. The goals for BLISS TESs are: noise equivalent power (NEP) = 5x10 (sup -20) W/Hz(exp 1/2) and response time tau <30ms. We expect background-limited performance from bilayers TESs with T(sub c) = 65mK and G=15fW/K. However, such TESs cannot be operated at 50mK unless stray power on the devices, or dark power P(sub D), is less than 200aW. We describe criteria for measuring P(sub D) that requires accurate knowledge of TC. Ultimately, we fabricated superconducting thermistors from Ir (T(sub c) >= 135mK) and Mo/Cu proximitized bilayers, where T(sub c) is the thermistor transition temperature. We measured the Ir TES arrays in our 50mK adiabatic demagnetization refrigerator test system, which can measure up to eight 1x32 arrays simultaneously using a time-division multiplexer, as well as our single-pixel test system which can measure down to 15mK. In our previous Ir array measurements our best reported performance was NEP=2.5x10(exp -19) W/Hz(sub 1/2) and Tau approximately equals 5ms for straight-beam TESs. In fact, we expected NEP approximately equals 1.5x10(exp -19)?W/Hz(sup 1/2) for meander beam TESs, but did not achieve this previously due to 1/f noise. Here, we detail improvements toward measuring the expected NEP and demonstrate NEP=(1.3+0.2)x10 (sup -19)W/Hz(exp 1/2) in our single-pixel test system and NEP=(1.6+/-0.3)x10(sup -19)W/Hz(sup 1/2) in our array test system.

FOREVER YOUNG FLOWER Negatively Regulates Ethylene Response DNA-Binding Factors by Activating an Ethylene-Responsive Factor to Control Arabidopsis Floral Organ Senescence and Abscission.

PubMed

Chen, Wei-Han; Li, Pei-Fang; Chen, Ming-Kun; Lee, Yung-I; Yang, Chang-Hsien

2015-08-01

In this study of Arabidopsis (Arabidopsis thaliana), we investigated the relationship between FOREVER YOUNG FLOWER (FYF) and Ethylene Response DNA-binding Factors (EDFs) and functionally analyzed a key FYF target, an Ethylene-Responsive Factor (ERF), that controls flower senescence/abscission. Ectopic expression of EDF1/2/3/4 caused promotion of flower senescence/abscission and the activation of the senescence-associated genes. The presence of a repressor domain in EDFs and the enhancement of the promotion of senescence/abscission in EDF1/2/3/4+SRDX (converting EDFs to strong repressors by fusion with the ERF-associated amphiphilic repression motif repression domain SRDX) transgenic plants suggested that EDFs act as repressors. The significant reduction of β-glucuronidase (GUS) expression by 35S:FYF in EDF1/2/3/4:GUS plants indicates that EDF1/2/3/4 functions downstream of FYF in regulating flower senescence/abscission. In this study, we also characterized an ERF gene, FOREVER YOUNG FLOWER UP-REGULATING FACTOR1 (FUF1), which is up-regulated by FYF during flower development. Ectopic expression of FUF1 caused similar delayed flower senescence/abscission as seen in 35S:FYF plants. This phenotype was correlated with deficient abscission zone formation, ethylene insensitivity, and down-regulation of EDF1/2/3/4 and abscission-associated genes in 35S:FUF1 flowers. In contrast, significant promotion of flower senescence/abscission and up-regulation of EDF1/2/3/4 were observed in 35S:FUF1+SRDX transgenic dominant-negative plants, in which FUF1 is converted to a potent repressor by fusion to an SRDX-suppressing motif. Thus, FUF1 acts as an activator in suppressing EDF1/2/3/4 function and senescence/abscission of the flowers. Our results reveal that FYF regulates flower senescence/abscission by negatively regulating EDF1/2/3/4, which is the downstream gene in the ethylene response, by activating FUF1 in Arabidopsis. © 2015 American Society of Plant Biologists. All Rights

Neutral endopeptidase inhibits prostate cancer cell migration by blocking focal adhesion kinase signaling.

PubMed

Sumitomo, M; Shen, R; Walburg, M; Dai, J; Geng, Y; Navarro, D; Boileau, G; Papandreou, C N; Giancotti, F G; Knudsen, B; Nanus, D M

2000-12-01

Neutral endopeptidase 24.11 (NEP, CD10) is a cell-surface enzyme expressed by prostatic epithelial cells that cleaves and inactivates neuropeptides implicated in the growth of androgen-independent prostate cancer (PC). NEP substrates such as bombesin and endothelin-1 induce cell migration. We investigated the mechanisms of NEP regulation of cell migration in PC cells, including regulation of phosphorylation on tyrosine of focal adhesion kinase (FAK). Western analyses and cell migration assays revealed an inverse correlation between NEP expression and the levels of FAK phosphorylation and cell migration in PC cell lines. Constitutively expressed NEP, recombinant NEP, and induced NEP expression using a tetracycline-repressive expression system inhibited bombesin- and endothelin-1-stimulated FAK phosphorylation and cell migration. This results from NEP-induced inhibition of neuropeptide-stimulated association of FAK with cSrc protein. Expression of a mutated catalytically inactive NEP protein also resulted in partial inhibition of FAK phosphorylation and cell migration. Coimmunoprecipitation experiments show that NEP associates with tyrosine-phosphorylated Lyn kinase, which then binds the p85 subunit of phosphatidylinositol 3-kinase (PI3-K) resulting in an NEP-Lyn-PI3-K protein complex. This complex competitively blocks FAK-PI3-K interaction, suggesting that NEP protein inhibits cell migration via a protein-protein interaction independent of its catalytic function. These experiments demonstrate that NEP can inhibit FAK phosphorylation on tyrosine and PC cell migration through multiple pathways and suggest that cell migration which contributes to invasion and metastases in PC cells can be regulated by NEP.

Neutral endopeptidase inhibits prostate cancer cell migration by blocking focal adhesion kinase signaling

PubMed Central

Sumitomo, Makoto; Shen, Ruoqian; Walburg, Marc; Dai, Jie; Geng, Yiping; Navarro, Daniel; Boileau, Guy; Papandreou, Christos N.; Giancotti, Filippo G.; Knudsen, Beatrice; Nanus, David M.

2000-01-01

Neutral endopeptidase 24.11 (NEP, CD10) is a cell-surface enzyme expressed by prostatic epithelial cells that cleaves and inactivates neuropeptides implicated in the growth of androgen-independent prostate cancer (PC). NEP substrates such as bombesin and endothelin-1 induce cell migration. We investigated the mechanisms of NEP regulation of cell migration in PC cells, including regulation of phosphorylation on tyrosine of focal adhesion kinase (FAK). Western analyses and cell migration assays revealed an inverse correlation between NEP expression and the levels of FAK phosphorylation and cell migration in PC cell lines. Constitutively expressed NEP, recombinant NEP, and induced NEP expression using a tetracycline-repressive expression system inhibited bombesin- and endothelin-1–stimulated FAK phosphorylation and cell migration. This results from NEP-induced inhibition of neuropeptide-stimulated association of FAK with cSrc protein. Expression of a mutated catalytically inactive NEP protein also resulted in partial inhibition of FAK phosphorylation and cell migration. Coimmunoprecipitation experiments show that NEP associates with tyrosine-phosphorylated Lyn kinase, which then binds the p85 subunit of phosphatidylinositol 3-kinase (PI3-K) resulting in an NEP-Lyn-PI3-K protein complex. This complex competitively blocks FAK-PI3-K interaction, suggesting that NEP protein inhibits cell migration via a protein-protein interaction independent of its catalytic function. These experiments demonstrate that NEP can inhibit FAK phosphorylation on tyrosine and PC cell migration through multiple pathways and suggest that cell migration which contributes to invasion and metastases in PC cells can be regulated by NEP. PMID:11104793

Copper Sensing Function of Drosophila Metal-Responsive Transcription Factor-1 Is Mediated By a Tetranuclear Cu(I) Cluster

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chen, X.; Hua, H.; Balamurugan, K.

2009-05-12

Drosophila melanogaster MTF-1 (dMTF-1) is a copper-responsive transcriptional activator that mediates resistance to Cu, as well as Zn and Cd. Here, we characterize a novel cysteine-rich domain which is crucial for sensing excess intracellular copper by dMTF-1. Transgenic flies expressing mutant dMTF-1 containing alanine substitutions of two, four or six cysteine residues within the sequence {sup 547}CNCTNCKCDQTKSCHGGDC{sup 565} are significantly or completely impaired in their ability to protect flies from copper toxicity and fail to up-regulate MtnA (metallothionein) expression in response to excess Cu. In contrast, these flies exhibit wild-type survival in response to copper deprivation thus revealing that themore » cysteine cluster domain is required only for sensing Cu load by dMTF-1. Parallel studies show that the isolated cysteine cluster domain is required to protect a copper-sensitive S. cerevisiae ace1 strain from copper toxicity. Cu(I) ligation by a Cys-rich domain peptide fragment drives the cooperative assembly of a polydentate [Cu{sub 4}-S{sub 6}] cage structure, characterized by a core of trigonally S{sub 3} coordinated Cu(I) ions bound by bridging thiolate ligands. While reminiscent of Cu{sub 4}-L{sub 6} (L = ligand) tetranuclear clusters in copper regulatory transcription factors of yeast, the absence of significant sequence homology is consistent with convergent evolution of a sensing strategy particularly well suited for Cu(I).« less

Factor X/Xa elicits protective signaling responses in endothelial cells directly via PAR-2 and indirectly via endothelial protein C receptor-dependent recruitment of PAR-1.

PubMed

Bae, Jong-Sup; Yang, Likui; Rezaie, Alireza R

2010-11-05

We recently demonstrated that the Gla domain-dependent interaction of protein C with endothelial protein C receptor (EPCR) leads to dissociation of the receptor from caveolin-1 and recruitment of PAR-1 to a protective signaling pathway. Thus, the activation of PAR-1 by either thrombin or PAR-1 agonist peptide elicited a barrier-protective response if endothelial cells were preincubated with protein C. In this study, we examined whether other vitamin K-dependent coagulation protease zymogens can modulate PAR-dependent signaling responses in endothelial cells. We discovered that the activation of both PAR-1 and PAR-2 in endothelial cells pretreated with factor FX (FX)-S195A, but not other procoagulant protease zymogens, also results in initiation of protective intracellular responses. Interestingly, similar to protein C, FX interaction with endothelial cells leads to dissociation of EPCR from caveolin-1 and recruitment of PAR-1 to a protective pathway. Further studies revealed that, FX activated by factor VIIa on tissue factor bearing endothelial cells also initiates protective signaling responses through the activation of PAR-2 independent of EPCR mobilization. All results could be recapitulated by the receptor agonist peptides to both PAR-1 and PAR-2. These results suggest that a cross-talk between EPCR and an unknown FX/FXa receptor, which does not require interaction with the Gla domain of FX, recruits PAR-1 to protective signaling pathways in endothelial cells.

A ChIP-chip approach reveals a novel role for transcription factor IRF1 in the DNA damage response.

PubMed

Frontini, Mattia; Vijayakumar, Meeraa; Garvin, Alexander; Clarke, Nicole

2009-03-01

IRF1 is a transcription factor that regulates key processes in the immune system and in tumour suppression. To gain further insight into IRF1's role in these processes, we searched for new target genes by performing chromatin immunoprecipitation coupled to a CpG island microarray (ChIP-chip). Using this approach we identified 202 new IRF1-binding sites with high confidence. Functional categorization of the target genes revealed a surprising cadre of new roles that can be linked to IRF1. One of the major functional categories was the DNA damage response pathway. In order to further validate our findings, we show that IRF1 can regulate the mRNA expression of a number of the DNA damage response genes in our list. In particular, we demonstrate that the mRNA and protein levels of the DNA repair protein BRIP1 [Fanconi anemia gene J (FANC J)] are upregulated after IRF1 over-expression. We also demonstrate that knockdown of IRF1 by siRNA results in loss of BRIP1 expression, abrogation of BRIP1 foci after DNA interstrand crosslink (ICL) damage and hypersensitivity to the DNA crosslinking agent, melphalan; a characteristic phenotype of FANC J cells. Taken together, our data provides a more complete understanding of the regulatory networks controlled by IRF1 and reveals a novel role for IRF1 in regulating the ICL DNA damage response.

A ChIP–chip approach reveals a novel role for transcription factor IRF1 in the DNA damage response

PubMed Central

Frontini, Mattia; Vijayakumar, Meeraa; Garvin, Alexander; Clarke, Nicole

2009-01-01

IRF1 is a transcription factor that regulates key processes in the immune system and in tumour suppression. To gain further insight into IRF1's role in these processes, we searched for new target genes by performing chromatin immunoprecipitation coupled to a CpG island microarray (ChIP–chip). Using this approach we identified 202 new IRF1-binding sites with high confidence. Functional categorization of the target genes revealed a surprising cadre of new roles that can be linked to IRF1. One of the major functional categories was the DNA damage response pathway. In order to further validate our findings, we show that IRF1 can regulate the mRNA expression of a number of the DNA damage response genes in our list. In particular, we demonstrate that the mRNA and protein levels of the DNA repair protein BRIP1 [Fanconi anemia gene J (FANC J)] are upregulated after IRF1 over-expression. We also demonstrate that knockdown of IRF1 by siRNA results in loss of BRIP1 expression, abrogation of BRIP1 foci after DNA interstrand crosslink (ICL) damage and hypersensitivity to the DNA crosslinking agent, melphalan; a characteristic phenotype of FANC J cells. Taken together, our data provides a more complete understanding of the regulatory networks controlled by IRF1 and reveals a novel role for IRF1 in regulating the ICL DNA damage response. PMID:19129219

PITX1, a specificity determinant in the HIF-1α-mediated transcriptional response to hypoxia

PubMed Central

Mudie, Sharon; Bandarra, Daniel; Batie, Michael; Biddlestone, John; Moniz, Sonia; Ortmann, Brian; Shmakova, Alena; Rocha, Sonia

2014-01-01

Hypoxia is an important developmental cue for multicellular organisms but it is also a contributing factor for several human pathologies, such as stroke, cardiovascular diseases and cancer. In cells, hypoxia activates a major transcriptional program coordinated by the Hypoxia Inducible Factor (HIF) family. HIF can activate more than one hundred targets but not all of them are activated at the same time, and there is considerable cell type variability. In this report we identified the paired-like homeodomain pituitary transcription factor (PITX1), as a transcription factor that helps promote specificity in HIF-1α dependent target gene activation. Mechanistically, PITX1 associates with HIF-1β and it is important for the induction of certain HIF-1 dependent genes but not all. In particular, PITX1 controls the HIF-1α-dependent expression of the histone demethylases; JMJD2B, JMJD2A, JMJD2C and JMJD1B. Functionally, PITX1 is required for the survival and proliferation responses in hypoxia, as PITX1 depleted cells have higher levels of apoptotic markers and reduced proliferation. Overall, our study identified PITX1 as a key specificity factor in HIF-1α dependent responses, suggesting PITX1 as a protein to target in hypoxic cancers. PMID:25558831

Neutral endopeptidase: variable expression in human lung, inactivation in lung cancer, and modulation of peptide-induced calcium flux.

PubMed

Cohen, A J; Bunn, P A; Franklin, W; Magill-Solc, C; Hartmann, C; Helfrich, B; Gilman, L; Folkvord, J; Helm, K; Miller, Y E

1996-02-15

Neutral endopeptidase (NEP; CALLA, CD10, EC 3.4.24.11) is a cell surface endopeptidase that hydrolyses bioactive peptides, including the bombesin-like peptides, as well as other neuropeptides. Bombesin-like peptides and other neuropeptides are autocrine growth factors for both small cell lung cancer (SCLC) and non-small cell lung cancer (NSCLC). Low expression of NEP has been reported in SCLC and NSCLC cell lines. NEP inhibition has been shown to increase proliferation in one cell line. To date, NEP expression has not been quantitatively evaluated in normal adult lung, SCLC or NSCLC tumors, paired uninvolved lung from the same patient, or in other pulmonary neoplasms such as mesotheliomas and carcinoids. We examined the expression of NEP in these tissues and human cell lines using immunohistochemistry, flow cytometry, enzyme activity, ELISA, Western blot, and reverse transcription (RT)-PCR. Uninvolved lung tissue from different individuals displayed considerable variation in NEP activity and protein. By immunohistochemistry, NEP expression was detectable in alveolar and airway epithelium, fibroblasts of normal lung, and in mesotheliomas, whereas it was undetectable in most SCLC, adenocarcinoma, squamous cell carcinoma, and carcinoid tumors of the lung. NEP activity and protein levels were lower in all SCLC and adenocarcinoma tumors when compared to adjacent uninvolved lung, often at levels consistent with expression derived from contaminating stroma. NEP expression and activity were reduced or undetectable in most SCLC and lung adenocarcinoma cell lines. NEP mRNA by RT-PCR was not expressed or was in low abundance in the majority of lung cancer cell lines. The majority of lung tumors did not express NEP by RT-PCR as compared with normal adjacent lung. In addition, recombinant NEP abolished, whereas an NEP inhibitor potentiated, the calcium flux generated by neuropeptides in some lung cancer cell lines, demonstrating potential physiological significance for low NEP

Glycogen synthase kinase 3 regulates expression of nuclear factor-erythroid-2 related transcription factor-1 (Nrf1) and inhibits pro-survival function of Nrf1

DOE Office of Scientific and Technical Information (OSTI.GOV)

Biswas, Madhurima; Kwong, Erick K.; Park, Eujean

2013-08-01

Nuclear factor E2-related factor-1 (Nrf1) is a basic leucine zipper transcription factor that is known to regulate antioxidant and cytoprotective gene expression. It was recently shown that Nrf1 is regulated by SCF–Fbw7 ubiquitin ligase. However our knowledge of upstream signals that targets Nrf1 for degradation by the UPS is not known. We report here that Nrf1 expression is negatively regulated by glycogen synthase kinase 3 (GSK3) in Fbw7-dependent manner. We show that GSK3 interacts with Nrf1 and phosphorylates the Cdc4 phosphodegron domain (CPD) in Nrf1. Mutation of serine residue in the CPD of Nrf1 to alanine (S350A), blocks Nrf1 frommore » phosphorylation by GSK3, and stabilizes Nrf1. Knockdown of Nrf1 and expression of a constitutively active form of GSK3 results in increased apoptosis in neuronal cells in response to ER stress, while expression of the GSK3 phosphorylation resistant S350A–Nrf1 attenuates apoptotic cell death. Together these data suggest that GSK3 regulates Nrf1 expression and cell survival function in response to stress activation. Highlights: • The effect of GSK3 on Nrf1 expression was examined. • GSK3 destabilizes Nrf1 protein via Fbw7 ubiquitin ligase. • GSK3 binds and phosphorylates Nrf1. • Protection from stress-induced apoptosis by Nrf1 is inhibited by GSK3.« less

The Iron-Dependent Regulation of the Candida albicans Oxidative Stress Response by the CCAAT-Binding Factor

PubMed Central

Chakravarti, Ananya; Camp, Kyle; McNabb, David S.

2017-01-01

Candida albicans is the most frequently encountered fungal pathogen in humans, capable of causing mucocutaneous and systemic infections in immunocompromised individuals. C. albicans virulence is influenced by multiple factors. Importantly, iron acquisition and avoidance of the immune oxidative burst are two critical barriers for survival in the host. Prior studies using whole genome microarray expression data indicated that the CCAAT-binding factor is involved in the regulation of iron uptake/utilization and the oxidative stress response. This study examines directly the role of the CCAAT-binding factor in regulating the expression of oxidative stress genes in response to iron availability. The CCAAT-binding factor is a heterooligomeric transcription factor previously shown to regulate genes involved in respiration and iron uptake/utilization in C. albicans. Since these pathways directly influence the level of free radicals, it seemed plausible the CCAAT-binding factor regulates genes necessary for the oxidative stress response. In this study, we show the CCAAT-binding factor is involved in regulating some oxidative stress genes in response to iron availability, including CAT1, SOD4, GRX5, and TRX1. We also show that CAT1 expression and catalase activity correlate with the survival of C. albicans to oxidative stress, providing a connection between iron obtainability and the oxidative stress response. We further explore the role of the various CCAAT-binding factor subunits in the formation of distinct protein complexes that modulate the transcription of CAT1 in response to iron. We find that Hap31 and Hap32 can compensate for each other in the formation of an active transcriptional complex; however, they play distinct roles in the oxidative stress response during iron limitation. Moreover, Hap43 was found to be solely responsible for the repression observed under iron deprivation. PMID:28122000

Glucocorticoids inhibit sulfur mustard-induced airway muscle hyperresponsiveness to substance P.

PubMed

Calvet, J H; D'Ortho, M P; Jarreau, P H; Levame, M; Harf, A; Macquin-Mavier, I

1994-11-01

To explore the mechanisms of airway hyperreactivity to aerosolized substance P observed in guinea pigs 14 days after intratracheal injection of sulfur mustard (SM), we studied the effects of epithelium removal and inhibition of neutral endopeptidase (NEP) activity on airway muscle responsiveness. Tracheal rings from SM-intoxicated guinea pigs expressed a greater contractile response to substance P than rings from nonintoxicated guinea pigs. After epithelium removal or incubation with the NEP inhibitor phosphoramidon, the contractile responses of tracheal rings to substance P did not differ in guinea pigs injected with SM or ethanol (SM solvent). Treatment of the guinea pigs with betamethasone for 7 days before measurement abolished the airway muscle hyperresponsiveness observed in untreated SM-intoxicated guinea pigs and partially restored tracheal epithelium NEP activity. In addition, the tracheal epithelium height and cell density of SM-intoxicated guinea pigs treated with betamethasone were significantly greater than in those without betamethasone. These results demonstrate that SM intoxication induces airway muscle hyperresponsiveness to substance P by reducing tracheal epithelial NEP activity and that glucocorticoids might inhibit this hyperresponsiveness by increasing this activity.

Influence of Environmental Factors on Biotic Responses to Nutrient Enrichment in Agricultural Streams1

PubMed Central

Maret, Terry R; Konrad, Christopher P; Tranmer, Andrew W

2010-01-01

The influence of environmental factors on biotic responses to nutrients was examined in three diverse agricultural regions of the United States. Seventy wadeable sites were selected along an agricultural land use gradient while minimizing natural variation within each region. Nutrients, habitat, algae, macroinvertebrates, and macrophyte cover were sampled during a single summer low-flow period in 2006 or 2007. Continuous stream stage and water temperature were collected at each site for 30 days prior to sampling. Wide ranges of concentrations were found for total nitrogen (TN) (0.07-9.61 mg/l) and total phosphorus (TP) (<0.004-0.361 mg/l), but biotic responses including periphytic and sestonic chlorophyll a (RCHL and SCHL, respectively), and percent of stream bed with aquatic macrophyte (AQM) growth were not strongly related to concentrations of TN or TP. Pearson’s coefficient of determination (R2) for nutrients and biotic measures across all sites ranged from 0.08 to 0.32 and generally were not higher within each region. The biotic measures (RCHL, SCHL, and AQM) were combined in an index to evaluate eutrophic status across sites that could have different biotic responses to nutrient enrichment. Stepwise multiple regression identified TN, percent canopy, median riffle depth, and daily percent change in stage as significant factors for the eutrophic index (R2 = 0.50, p < 0.001). A TN threshold of 0.48 mg/l was identified where eutrophic index scores became less responsive to increasing TN concentrations, for all sites. Multiple plant growth indicators should be used when evaluating eutrophication, especially when streams contain an abundance of macrophytes. PMID:22457568

Transient α-helices in the disordered RPEL motifs of the serum response factor coactivator MKL1

NASA Astrophysics Data System (ADS)

Mizuguchi, Mineyuki; Fuju, Takahiro; Obita, Takayuki; Ishikawa, Mitsuru; Tsuda, Masaaki; Tabuchi, Akiko

2014-06-01

The megakaryoblastic leukemia 1 (MKL1) protein functions as a transcriptional coactivator of the serum response factor. MKL1 has three RPEL motifs (RPEL1, RPEL2, and RPEL3) in its N-terminal region. MKL1 binds to monomeric G-actin through RPEL motifs, and the dissociation of MKL1 from G-actin promotes the translocation of MKL1 to the nucleus. Although structural data are available for RPEL motifs of MKL1 in complex with G-actin, the structural characteristics of RPEL motifs in the free state have been poorly defined. Here we characterized the structures of free RPEL motifs using NMR and CD spectroscopy. NMR and CD measurements showed that free RPEL motifs are largely unstructured in solution. However, NMR analysis identified transient α-helices in the regions where helices α1 and α2 are induced upon binding to G-actin. Proline mutagenesis showed that the transient α-helices are locally formed without helix-helix interactions. The helix content is higher in the order of RPEL1, RPEL2, and RPEL3. The amount of preformed structure may correlate with the binding affinity between the intrinsically disordered protein and its target molecule.

Comparative analysis of the ternary complex factors Elk-1, SAP-1a and SAP-2 (ERP/NET).

PubMed Central

Price, M A; Rogers, A E; Treisman, R

1995-01-01

A transcription factor ternary complex composed of Serum Response Factor (SRF) and Ternary Complex Factor (TCF) mediates the response of the c-fos Serum Response Element (SRE) to growth factors and mitogens. Three Ets domain proteins, Elk-1, SAP-1 and ERP/NET, have been reported to have the properties of TCF. Here we compare Elk-1 and SAP-1a with the human ERP/NET homologue SAP-2. All three TCF RNAs are ubiquitously expressed at similar relative levels. All three proteins contain conserved regions that interact with SRF and the c-fos SRE with comparable efficiency, but in vitro complex formation by SAP-2 is strongly inhibited by its C-terminal sequences. Similarly, only Elk-1 and SAP-1a efficiently bind the c-fos SRE in vivo; ternary complex formation by SAP-2 is weak and is substantially unaffected by serum stimulation or v-ras co-expression. All three TCFs contain C-terminal transcriptional activation domains that are phosphorylated following growth factor stimulation. Activation requires conserved S/T-P motifs found in all the TCF family members. Each TCF activation domain can be phosphorylated in vitro by partially purified ERK2, and ERK activation in vivo is sufficient to potentiate transcriptional activation. Images PMID:7540136

Comparative analysis of the ternary complex factors Elk-1, SAP-1a and SAP-2 (ERP/NET).

PubMed

Price, M A; Rogers, A E; Treisman, R

1995-06-01

A transcription factor ternary complex composed of Serum Response Factor (SRF) and Ternary Complex Factor (TCF) mediates the response of the c-fos Serum Response Element (SRE) to growth factors and mitogens. Three Ets domain proteins, Elk-1, SAP-1 and ERP/NET, have been reported to have the properties of TCF. Here we compare Elk-1 and SAP-1a with the human ERP/NET homologue SAP-2. All three TCF RNAs are ubiquitously expressed at similar relative levels. All three proteins contain conserved regions that interact with SRF and the c-fos SRE with comparable efficiency, but in vitro complex formation by SAP-2 is strongly inhibited by its C-terminal sequences. Similarly, only Elk-1 and SAP-1a efficiently bind the c-fos SRE in vivo; ternary complex formation by SAP-2 is weak and is substantially unaffected by serum stimulation or v-ras co-expression. All three TCFs contain C-terminal transcriptional activation domains that are phosphorylated following growth factor stimulation. Activation requires conserved S/T-P motifs found in all the TCF family members. Each TCF activation domain can be phosphorylated in vitro by partially purified ERK2, and ERK activation in vivo is sufficient to potentiate transcriptional activation.

Impact of Insulin Degrading Enzyme and Neprilysin in Alzheimer's Disease Biology: Characterization of Putative Cognates for Therapeutic Applications.

PubMed

Jha, Niraj Kumar; Jha, Saurabh Kumar; Kumar, Dhiraj; Kejriwal, Noopur; Sharma, Renu; Ambasta, Rashmi K; Kumar, Pravir

2015-01-01

Alzheimer's disease (AD) is a neurodegenerative process primarily characterized by amyloid-β (Aβ) agglomeration, neuroinflammation, and cognitive dysfunction. The prominent cause for dementia is the deposition of Aβ plaques and tau-neurofibrillary tangles that hamper the neuronal organization and function. Aβ pathology further affects numerous signaling cascades that disturb the neuronal homeostasis. For instance, Aβ deposition is responsible for altered expression of insulin encoding genes that lead to insulin resistance, and thereby affecting insulin signaling pathway and glucose metabolism in the brain. As a result, the common pathology of insulin resistance between Type-2 diabetes mellitus and AD has led AD to be proposed as a form of diabetes and termed 'Type-3 diabetes'. Since accumulation of Aβ is the prominent cause of neuronal toxicity in AD, its clearance is the prime requisite for therapeutic prospects. This purpose is expertly fulfilled by the potential role of Aβ degrading enzymes such as insulin degrading enzyme (IDE) and Neprilysin (NEP). Therefore, their molecular study is important to uncover the proteolytic and regulatory mechanism of Aβ degradation. Herein, (i) In silico sequential and structural analysis of IDE and NEP has been performed to identify the molecular entities for proteolytic degradation of Aβ in the AD brain, (ii) to analyze their catalytic site to demonstrate the enzymatic action played by IDE and NEP, (iii) to identify their structural homologues that could behave as putative partners of IDE and NEP with similar catalytic action and (iv) to illustrate various IDE- and NEP-mediated therapeutic approaches and factors for clearing Aβ in AD.

Neprilysins: an evolutionarily conserved family of metalloproteases that play important roles in reproduction in Drosophila.

PubMed

Sitnik, Jessica L; Francis, Carmen; Hens, Korneel; Huybrechts, Roger; Wolfner, Mariana F; Callaerts, Patrick

2014-03-01

Members of the M13 class of metalloproteases have been implicated in diseases and in reproductive fitness. Nevertheless, their physiological role remains poorly understood. To obtain a tractable model with which to analyze this protein family's function, we characterized the gene family in Drosophila melanogaster and focused on reproductive phenotypes. The D. melanogaster genome contains 24 M13 class protease homologs, some of which are orthologs of human proteases, including neprilysin. Many are expressed in the reproductive tracts of either sex. Using RNAi we individually targeted the five Nep genes most closely related to vertebrate neprilysin, Nep1-5, to investigate their roles in reproduction. A reduction in Nep1, Nep2, or Nep4 expression in females reduced egg laying. Nep1 and Nep2 are required in the CNS and the spermathecae for wild-type fecundity. Females that are null for Nep2 also show defects as hosts of sperm competition as well as an increased rate of depletion for stored sperm. Furthermore, eggs laid by Nep2 mutant females are fertilized normally, but arrest early in embryonic development. In the male, only Nep1 was required to induce normal patterns of female egg laying. Reduction in the expression of Nep2-5 in the male did not cause any dramatic effects on reproductive fitness, which suggests that these genes are either nonessential for male fertility or perform redundant functions. Our results suggest that, consistent with the functions of neprilysins in mammals, these proteins are also required for reproduction in Drosophila, opening up this model system for further functional analysis of this protein class and their substrates.

Neprilysins: An Evolutionarily Conserved Family of Metalloproteases That Play Important Roles in Reproduction in Drosophila

PubMed Central

Sitnik, Jessica L.; Francis, Carmen; Hens, Korneel; Huybrechts, Roger; Wolfner, Mariana F.; Callaerts, Patrick

2014-01-01

Members of the M13 class of metalloproteases have been implicated in diseases and in reproductive fitness. Nevertheless, their physiological role remains poorly understood. To obtain a tractable model with which to analyze this protein family’s function, we characterized the gene family in Drosophila melanogaster and focused on reproductive phenotypes. The D. melanogaster genome contains 24 M13 class protease homologs, some of which are orthologs of human proteases, including neprilysin. Many are expressed in the reproductive tracts of either sex. Using RNAi we individually targeted the five Nep genes most closely related to vertebrate neprilysin, Nep1-5, to investigate their roles in reproduction. A reduction in Nep1, Nep2, or Nep4 expression in females reduced egg laying. Nep1 and Nep2 are required in the CNS and the spermathecae for wild-type fecundity. Females that are null for Nep2 also show defects as hosts of sperm competition as well as an increased rate of depletion for stored sperm. Furthermore, eggs laid by Nep2 mutant females are fertilized normally, but arrest early in embryonic development. In the male, only Nep1 was required to induce normal patterns of female egg laying. Reduction in the expression of Nep2-5 in the male did not cause any dramatic effects on reproductive fitness, which suggests that these genes are either nonessential for male fertility or perform redundant functions. Our results suggest that, consistent with the functions of neprilysins in mammals, these proteins are also required for reproduction in Drosophila, opening up this model system for further functional analysis of this protein class and their substrates. PMID:24395329

Elucidating Pathogenic Mechanisms of Early-onset Alzheimer's Disease in Down Syndrome Patients.

PubMed

Asai, Masashi; Kawakubo, Takashi; Mori, Ryotaro; Iwata, Nobuhisa

2017-01-01

Down syndrome (DS) patients demonstrate the neuropathology of Alzheimer's disease (AD) characterized by the formation of senile plaques and neurofibrillary tangles by age 40-50 years. It has been considered for a number of years that 1.5-fold expression of the gene for the amyloid precursor protein (APP) located on chromosome 21 leading to overproduction of amyloid-β peptide (Aβ) results in the early onset of AD in adults with DS. However, the mean age of onset of familial AD with the Swedish mutation on APP which has high affinity for β-secretase associated with a dramatic increase in Aβ production is about 55 years. This paradox indicates that there is a poor correlation between average ages of AD onset and the theoretical amount of Aβ production and that there are factors exacerbating AD on chromosome 21. We therefore focused on dual-specificity tyrosine phosphorylation-regulated kinase 1A (DYRK1A), since overexpressing transgenic mice show AD-like brain pathology. The overexpression of DYRK1A caused suppression of the activity of neprilysin (NEP), which is a major Aβ-degrading enzyme in the brain, and phosphorylation at the NEP cytoplasmic domain. NEP activity was markedly reduced in fibroblasts derived from DS patients compared with that in fibroblasts derived from healthy controls. This impaired activity of NEP was rescued by DYRK1A inhibition. These results show that DYRK1A overexpression causes suppression of NEP activity through its phosphorylation in DS patients. Our results suggest that DYRK1A inhibitors could be effective against AD not only in adults with DS but also in sporadic AD patients.

Neutral endopeptidase determines the severity of pancreatitis-associated lung injury.

PubMed

Day, Amy Lightner; Wick, Elizabeth; Jordan, Thomas H; Jaffray, Colleen E; Bunnett, Nigel W; Grady, Eileen F; Kirkwood, Kimberly S

2005-09-01

Neutral endopeptidase (NEP) is a cell-surface metalloprotease that degrades proinflammatory peptides such as substance P, neurokinin A, and bradykinin. Inhibition of NEP exacerbates both experimental pancreatitis and the associated lung injury. It is unclear if worsened lung injury is the indirect result of more severe pancreatitis or if it is a direct effect of NEP inhibition in the lung. We used a model of pancreatitis-associated lung injury (PALI) to test the hypothesis that antagonism or genetic deletion of NEP augments PALI inflammation and pulmonary damage irregardless of the degree of pancreatitic inflammation. In NEP(+/+) mice, intraperitoneal injection of porcine pancreatic elastase (elastase, 0.085 U/g at t = 0 h and t = 1 h) caused a 7-fold increase in lung myeloperoxidase (MPO) activity and marked pulmonary edema, neutrophil infiltration, and hemorrhage at 4 h as compared to control animals. The pattern of lung injury induced by elastase mimicked that observed among a separate group of animals with PALI induced by cerulein but was not associated with pancreatitis. Both NEP(-/-) mice and NEP(+/+) mice pretreated with the NEP antagonist phosphoramidon (10 mg/kg s.c.) had significant elevations of lung MPO and worsened lung histology compared to NEP(+/+) mice given elastase alone. Antagonism of either the vanilloid receptor transient receptor vanilloid 1 or the substance P receptor NK1-R had no effect on elastase-mediated lung injury in NEP-deficient mice. NEP is an inhibitor of pancreatic elastase-induced lung injury, presumably via degradation of proinflammatory mediators.

The impact of growing-season length variability on carbon assimilation and evapotranspiration over 88 years in the eastern US deciduous forest

PubMed

White; Running; Thornton

1999-02-01

Recent research suggests that increases in growing-season length (GSL) in mid-northern latitudes may be partially responsible for increased forest growth and carbon sequestration. We used the BIOME-BGC ecosystem model to investigate the impacts of including a dynamically regulated GSL on simulated carbon and water balance over a historical 88-year record (1900-1987) for 12 sites in the eastern USA deciduous broadleaf forest. For individual sites, the predicted GSL regularly varied by more than 15 days. When grouped into three climatic zones, GSL variability was still large and rapid. There is a recent trend in colder, northern sites toward a longer GSL, but not in moderate and warm climates. The results show that, for all sites, prediction of a long GSL versus using the mean GSL increased net ecosystem production (NEP), gross primary production (GPP), and evapotranspiration (ET); conversely a short GSL is predicted to decrease these parameters. On an absolute basis, differences in GPP between the dynamic and mean GSL simulations were larger than the differences in NEP. As a percentage difference, though, NEP was much more sensitive to changes in GSL than were either GPP or ET. On average, a 1-day change in GSL changed NEP by 1.6%, GPP by 0.5%, and ET by 0.2%. Predictions of NEP and GPP in cold climates were more sensitive to changes in GSL than were predictions in warm climates. ET was not similarly sensitive. First, our results strongly agree with field measurements showing a high correlation between NEP and dates of spring growth, and second they suggest that persistent increases in GSL may lead to long-term increases in carbon storage.

Adrenomedullin (ADM) in the human forearm vascular bed: effect of neutral endopeptidase inhibition and comparison with proadrenomedullin NH2-terminal 20 peptide (PAMP)

PubMed Central

Wilkinson, Ian B; McEniery, Carmel M; Bongaerts, Katherine H; MacCallum, Helen; Webb, David J; Cockcroft, John R

2001-01-01

Aims To compare the haemodynamic responses of proadrenomedullin N-terminal 20 peptide (PAMP) and adrenomedullin (ADM) in the forearm vascular bed of healthy male volunteers, and to investigate the role of neutral endopeptidase (NEP) in the metabolism of ADM. Methods On two separate occasions, ADM (1–30 pmol min−1) and PAMP (100–3000 pmol min−1) were infused into the brachial artery of eight male subjects, and forearm blood flow (FBF) assessed using venous occlusion plethysmography. In a second study, eight male subjects received the same doses of ADM, co-infused with either the NEP inhibitor thiorphan (30 nmol min−1) or the control vasoconstrictor noradrenaline (120 pmol min−1), on separate occasions. Both studies were conducted in a double-blind, randomized manner. Results ADM and PAMP produced a dose-dependent increase in FBF (P ≤ 0.002). Based on the dose producing a 50% increase in FBF, ADM was ∼60 times more potent than PAMP. Thiorphan and noradrenaline produced similar reductions in FBF of 14 ± 4% (mean ± s.e. mean) and 22 ± 6%, respectively (P = 0.4). However, the area under the dose–response curve was significantly greater during co-infusion of ADM with thiorphan than with noradrenaline (P = 0.028), as was the maximum increase in FBF ratio (2.1 ± 1.0 vs 1.2 ± 0.2; P = 0.030). Conclusions ADM and PAMP both produce a local dose-related vasodilatation in the human forearm, but PAMP is ∼60 times less potent than ADM. In addition, NEP inhibition potentiates the haemodynamic effects of ADM. These findings suggest that PAMP may not play a role in the physiological regulation of blood flow. However, in pathophysiological conditions such as hypertension and heart failure, NEP inhibition may exert a beneficial effect by increasing the biological activity of ADM. PMID:11488772

Development of Ultra-Low-Noise TES Bolometer Arrays

NASA Astrophysics Data System (ADS)

Suzuki, T.; Khosropanah, P.; Ridder, M. L.; Hijmering, R. A.; Gao, J. R.; Akamatsu, H.; Gottardi, L.; van der Kuur, J.; Jackson, B. D.

2016-07-01

SRON is developing ultra-low-noise transition edge sensors (TESs) based on a superconducting Ti/Au bilayer on a suspended SiN island with SiN legs for SAFARI aboard SPICA. We have two major concerns about realizing TESs with an ultra-low NEP of 2× 10^{-19} hbox {W}/√{{ {Hz}}}: achieving lower thermal conductance and no excess noise with respect to the phonon noise. To realize TESs with phonon-noise-limited NEPs, we need to make thinner ({<}0.25 \\upmu hbox {m}) and narrower ({<}1 \\upmu hbox {m}) SiN legs. With deep reactive-ion etching, three types of TESs were fabricated in combination with different SiN island sizes and the presence or absence of an optical absorber. Those TESs have a thin (0.20 \\upmu hbox {m}), narrow (0.5-0.7 \\upmu hbox {m}), and long (340-460 \\upmu hbox {m}) SiN legs and show Tc of {˜ }93 hbox {mK} and Rn of {˜ }158 hbox {m}{Ω }. These TESs were characterized under AC bias using our frequency-division multiplexing readout (1-3 MHz) system. TESs without the absorber show NEPs as low as 1.1 × 10^{-19} hbox {W}/√{{ {Hz}}} with a reasonable response speed ({<}1 hbox {ms}), which achieved the phonon noise limit. For TESs with the absorber, we confirmed a higher hbox {NEP}_{el} ({˜ }5 × 10^{-19} hbox {W}/√{{ {Hz}}}) than that of TESs without the absorber likely due to stray light. The lowest NEP can make the new version of SAFARI with a grating spectrometer feasible.

Early Growth Response-1 Induces and Enhances Vascular Endothelial Growth Factor-A Expression in Lung Cancer Cells

PubMed Central

Shimoyamada, Hiroaki; Yazawa, Takuya; Sato, Hanako; Okudela, Koji; Ishii, Jun; Sakaeda, Masashi; Kashiwagi, Korehito; Suzuki, Takehisa; Mitsui, Hideaki; Woo, Tetsukan; Tajiri, Michihiko; Ohmori, Takahiro; Ogura, Takashi; Masuda, Munetaka; Oshiro, Hisashi; Kitamura, Hitoshi

2010-01-01

Vascular endothelial growth factor-A (VEGF-A) is crucial for angiogenesis, vascular permeability, and metastasis during tumor development. We demonstrate here that early growth response-1 (EGR-1), which is induced by the extracellular signal–regulated kinase (ERK) pathway activation, activates VEGF-A in lung cancer cells. Increased EGR-1 expression was found in adenocarcinoma cells carrying mutant K-RAS or EGFR genes. Hypoxic culture, siRNA experiment, luciferase assays, chromatin immunoprecipitation, electrophoretic mobility shift assays, and quantitative RT-PCR using EGR-1–inducible lung cancer cells demonstrated that EGR-1 binds to the proximal region of the VEGF-A promoter, activates VEGF-A expression, and enhances hypoxia inducible factor 1α (HIF-1α)-mediated VEGF-A expression. The EGR-1 modulator, NAB-2, was rapidly induced by increased levels of EGR-1. Pathology samples of human lung adenocarcinomas revealed correlations between EGR-1/HIF-1α and VEGF-A expressions and relative elevation of EGR-1 and VEGF-A expression in mutant K-RAS- or EGFR-carrying adenocarcinomas. Both EGR-1 and VEGF-A expression increased as tumors dedifferentiated, whereas HIF-1α expression did not. Although weak correlation was found between EGR-1 and NAB-2 expressions on the whole, NAB-2 expression decreased as tumors dedifferentiated, and inhibition of DNA methyltransferase/histone deacetylase increased NAB-2 expression in lung cancer cells despite no epigenetic alteration in the NAB-2 promoter. These findings suggest that EGR-1 plays important roles on VEGF-A expression in lung cancer cells, and epigenetic silencing of transactivator(s) associated with NAB-2 expression might also contribute to upregulate VEGF-A expression. PMID:20489156

Neutral endopeptidase inhibitor potentiates the tachykinin-induced increase in ciliary beat frequency in rabbit trachea.

PubMed

Kondo, M; Tamaoki, J; Takizawa, T

1990-08-01

We used cultured rabbit tracheal epithelium to determine the effect of mammalian-derived tachykinin on airway ciliary activity and its modulation by neutral endopeptidase EC 3.4.24.11 (NEP). Neurokinin A (NKA) caused dose-dependent increases in ciliary beat frequency (CBF), as measured by a photoelectric method, with the maximal increase from the baseline 15.7 +/- 1.7% (mean +/- SEM, p less than 0.01), whereas substance P (SP) had no effect. The NKA-induced increase in CBF was not inhibited by phentolamine, propranolol, or atropine, but it was abolished by the tachykinin antagonist [D-Pro2, D-Trp7,9]SP. Pretreatment of tissue with thiorphan (10(-5) M), a NEP inhibitor, had little effect on CBF responses to NKA; however, it significantly potentiated the responses to SP (14.9 +/- 3.0%, p less than 0.01). Other peptidase inhibitors, including captopril, bestatin, and leupeptin, did not alter the tachykinin-induced CBF response, suggesting that angiotensin converting enzyme, aminopeptidases, and serine proteinases do not modulate ciliary activity in response to tachykinins. These results suggest that NKA increases CBF by acting directly on tachykinin receptors and that NEP may play a role in modulating the tachykinin-induced stimulatory effects on CBF.

Soybean DREB1/CBF-type transcription factors function in heat and drought as well as cold stress-responsive gene expression.

PubMed

Kidokoro, Satoshi; Watanabe, Keitaro; Ohori, Teppei; Moriwaki, Takashi; Maruyama, Kyonoshin; Mizoi, Junya; Myint Phyu Sin Htwe, Nang; Fujita, Yasunari; Sekita, Sachiko; Shinozaki, Kazuo; Yamaguchi-Shinozaki, Kazuko

2015-02-01

Soybean (Glycine max) is a globally important crop, and its growth and yield are severely reduced by abiotic stresses, such as drought, heat, and cold. The cis-acting element DRE (dehydration-responsive element)/CRT plays an important role in activating gene expression in response to these stresses. The Arabidopsis DREB1/CBF genes that encode DRE-binding proteins function as transcriptional activators in the cold stress responsive gene expression. In this study, we identified 14 DREB1-type transcription factors (GmDREB1s) from a soybean genome database. The expression of most GmDREB1 genes in soybean was strongly induced by a variety of abiotic stresses, such as cold, drought, high salt, and heat. The GmDREB1 proteins activated transcription via DREs (dehydration-responsive element) in Arabidopsis and soybean protoplasts. Transcriptome analyses using transgenic Arabidopsis plants overexpressing GmDREB1s indicated that many of the downstream genes are cold-inducible and overlap with those of Arabidopsis DREB1A. We then comprehensively analyzed the downstream genes of GmDREB1B;1, which is closely related to DREB1A, using a transient expression system in soybean protoplasts. The expression of numerous genes induced by various abiotic stresses were increased by overexpressing GmDREB1B;1 in soybean, and DREs were the most conserved element in the promoters of these genes. The downstream genes of GmDREB1B;1 included numerous soybean-specific stress-inducible genes that encode an ABA receptor family protein, GmPYL21, and translation-related genes, such as ribosomal proteins. We confirmed that GmDREB1B;1 directly activates GmPYL21 expression and enhances ABRE-mediated gene expression in an ABA-independent manner. These results suggest that GmDREB1 proteins activate the expression of numerous soybean-specific stress-responsive genes under diverse abiotic stress conditions. © 2014 The Authors The Plant Journal © 2014 John Wiley & Sons Ltd.

Basic Fibroblast Growth Factor Activates Serum Response Factor Gene Expression by Multiple Distinct Signaling Mechanisms

PubMed Central

Spencer, Jeffrey A.; Major, Michael L.; Misra, Ravi P.

1999-01-01

Serum response factor (SRF) plays a central role in the transcriptional response of mammalian cells to a variety of extracellular signals. It is a key regulator of many cellular early response genes which are believed to be involved in cell growth and differentiation. The mechanism by which SRF activates transcription in response to mitogenic agents has been extensively studied; however, significantly less is known about regulation of the SRF gene itself. Previously, we identified distinct regulatory elements in the SRF promoter that play a role in activation, including a consensus ETS domain binding site, a consensus overlapping Sp/Egr-1 binding site, and two SRF binding sites. We further showed that serum induces SRF by a mechanism that requires an intact SRF binding site, also termed a CArG box. In the present study we demonstrate that in response to stimulation of cells by a purified growth factor, basic fibroblast growth factor (bFGF), the SRF promoter is upregulated by a complex pathway that involves at least two independent mechanisms: a CArG box-independent mechanism that is mediated by an ETS binding site, and a novel CArG box-dependent mechanism that requires both an Sp factor binding site and the CArG motifs for maximal stimulation. Our analysis indicates that the CArG/Sp element activation mechanism is mediated by distinct signaling pathways. The CArG box-dependent component is targeted by a Rho-mediated pathway, and the Sp binding site-dependent component is targeted by a Ras-mediated pathway. Both SRF and bFGF have been implicated in playing an important role in mediating cardiogenesis during development. The implications of our findings for SRF expression during development are discussed. PMID:10330138

Neutral endopeptidase modulates substance P-induced vasodilation in vivo.

PubMed

Gao, X P; Rubinstein, I

1995-02-01

The purpose of this study was to investigate whether neutral endopeptidase (NEP; EC 3.4.24.11) modulates substance P-induced vasodilation in the oral mucosa in vivo. Using intravital microscopy, we measured the diameter of second-order arterioles (44-70 microns) in the hamster cheek pouch during suffusion of capsaicin and substance P. We found that capsaicin (0.1 and 10.0 nM) induced significant concentration-dependent vasodilations (13 +/- 4 and 39 +/- 7% increase from baseline, respectively; P < 0.05) that were significantly potentiated by phosphoramidon (10.0 nM), a selective NEP inhibitor (35 +/- 15 and 61 +/- 12% increase from baseline, respectively; P < 0.05). Substance P (0.1 and 10.0 nM) also induced significant concentration-dependent vasodilations (7 +/- 3 and 25 +/- 8% increase from baseline, respectively; P < 0.05) that were mediated by the COOH-terminal of the molecule. Substance P-induced responses were significantly potentiated by phosphoramidon (34 +/- 9 and 53 +/- 10% increase from baseline, respectively; P < 0.05) and thiorphan (10.0 microM), a selective NEP inhibitor (44 +/- 11 and 53 +/- 10% increase from baseline, respectively; P < 0.05). Substance P-(1-9) had no significant effects on arteriolar diameter. Suffusion of captopril, leupeptin, Bestatin, and DL-2-mercaptomethyl-3-guanidinoethylthiopropanoic acid together had no significant effects on substance P-induced vasodilation. Phosphoramidon did not potentiate nitroglycerin-induced vasodilation. These data indicate that NEP modulates substance P-induced vasodilation in the hamster cheek pouch in vivo. We suggest that any decrease in tissue NEP activity may amplify neurogenic vasodilation in the oral mucosa.

Aerosolized neutral endopeptidase reverses ozone-induced airway hyperreactivity to substance P.

PubMed

Murlas, C G; Lang, Z; Williams, G J; Chodimella, V

1992-03-01

We investigated the effects of ozone exposure (3.0 ppm, 2 h) on airway neutral endopeptidase (NEP) activity and bronchial reactivity to substance P in guinea pigs. Reactivity after ozone or air exposure was determined by measuring specific airway resistance in intact unanesthetized spontaneously breathing animals in response to increasing doses of intravenous substance P boluses. The effective dose of substance P (in micrograms) that produced a doubling of baseline specific airway resistance (ED200SP) was determined by interpolation of cumulative substance P dose-response curves. NEP activity was measured in tracheal homogenates made from each animal of other groups exposed to either ozone or room air. By reverse-phase high-pressure liquid chromatography, this activity was characterized by the phosphoramidon-inhibitable cleavage of alanine-p-nitroaniline from succinyl-(Ala)3-p-nitroaniline in the presence of 100 microM amastatin. Mean values of the changes in log ED200SP were 0.27 +/- 0.07 (SE) for the ozone-exposed group and 0.08 +/- 0.04 for the air-exposed group. We found that phosphoramidon significantly increased substance P reactivity in the air-exposed animals (P less than 0.01), but it had no effect in the ozone-exposed group. This finding was associated with a significant reduction in tracheal homogenate NEP activity of ozone-exposed animals compared with controls: mean values were 18.1 +/- 1.9 nmol.min-1.mg protein-1 for the ozone-exposed group and 25.1 +/- 2.4 nmol.min-1.mg protein-1 for air-exposed animals (P less than 0.05). Inhalation of an aerosolized NEP preparation, partially purified from guinea pig kidney, reversed the substance P hyperreactivity produced by ozone exposure.(ABSTRACT TRUNCATED AT 250 WORDS)

Aerosolized neutral endopeptidase reverses ozone-induced airway hyperreactivity to substance P

DOE Office of Scientific and Technical Information (OSTI.GOV)

Murlas, C.G.; Lang, Z.; Williams, G.J.

1992-03-01

The authors investigated the effects of ozone exposure (3.0 ppm, 2 h) on airway neutral endopeptidase (NEP) activity and bronchial reactivity to substance P in guinea pigs. Reactivity after ozone or air exposure was determined by measuring specific airway resistance in intact unanesthetized spontaneously breathing animals in response to increasing doses of intravenous substance P boluses. The effective dose of substance P (in micrograms) that produced a doubling of baseline specific airway resistance (ED200SP) was determined by interpolation of cumulative substance P dose-response curves. NEP activity was measured in tracheal homogenates made from each animal of other groups exposed tomore » either ozone or room air. By reverse-phase high-pressure liquid chromatography, this activity was characterized by the phosphoramidon-inhibitable cleavage of alanine-p-nitroaniline from succinyl-(Ala)3-p-nitroaniline in the presence of 100 microM amastatin. Mean values of the changes in log ED200SP were 0.27 +/- 0.07 (SE) for the ozone-exposed group and 0.08 +/- 0.04 for the air-exposed group. We found that phosphoramidon significantly increased substance P reactivity in the air-exposed animals (P less than 0.01), but it had no effect in the ozone-exposed group. This finding was associated with a significant reduction in tracheal homogenate NEP activity of ozone-exposed animals compared with controls: mean values were 18.1 +/- 1.9 nmol.min-1.mg protein-1 for the ozone-exposed group and 25.1 +/- 2.4 nmol.min-1.mg protein-1 for air-exposed animals (P less than 0.05). Inhalation of an aerosolized NEP preparation, partially purified from guinea pig kidney, reversed the substance P hyperreactivity produced by ozone exposure.(ABSTRACT TRUNCATED AT 250 WORDS)« less

Estimation of net ecosystem production in Asia using the diagnostic-type ecosystem model with a 10 km grid-scale resolution

NASA Astrophysics Data System (ADS)

Sasai, Takahiro; Obikawa, Hiroki; Murakami, Kazutaka; Kato, Soushi; Matsunaga, Tsuneo; Nemani, Ramakrishna R.

2016-06-01

The terrestrial carbon cycle in Asia is highly uncertain, and it affects our understanding of global warming. One of the important issues is the need for an enhancement of spatial resolution, since local regions in Asia are heterogeneous with regard to meteorology, land form, and land cover type, which greatly impacts the detailed spatial patterns in its ecosystem. Thus, an important goal of this study is to reasonably reproduce the heterogeneous biogeochemical patterns in Asia by enhancing the spatial resolution of the ecosystem model biosphere model integrating eco-physiological and mechanistic approaches using satellite data (BEAMS). We estimated net ecosystem production (NEP) over eastern Asia and examined the spatial differences in the factors controlling NEP by using a 10 km grid-scale approach over two different decades (2001-2010 and 2091-2100). The present and future meteorological inputs were derived from satellite observations and the downscaled Coupled Model Intercomparison Project Phase 5 (CMIP5) data set, respectively. The results showed that the present NEP in whole eastern Asia was carbon source (-214.9 TgC yr-1) and in future scenarios, the greatest positive (76.4 TgC yr-1) and least negative (-95.9 TgC yr-1) NEPs were estimated from the Representative Concentration Pathways (RCP) 6.0 and RCP8.5 scenarios, respectively. Calculated annual NEP in RCP8.5 was mostly positive in the southern part of East Asia and Southeast Asia and negative in northern and central parts of East Asia. Under the RCP scenario with higher greenhouse gases emission (RCP8.5), deciduous needleleaf and mixed forests distributed in the middle and high latitudes served as carbon source. In contrast, evergreen broadleaf forests distributed in low latitudes served as carbon sink. The sensitivity study demonstrated that the spatial tendency of NEP was largely influenced by atmospheric CO2 and temperature.

Zero-bias microwave detectors based on array of nanorectifiers coupled with a dipole antenna

NASA Astrophysics Data System (ADS)

Kasjoo, Shahrir R.; Singh, Arun K.; Mat Isa, Siti S.; Ramli, Muhammad M.; Mohamad Isa, Muammar; Ahmad, Norhawati; Mohd Nor, Nurul I.; Khalid, Nazuhusna; Song, Ai Min

2016-04-01

We report on zero-bias microwave detection using a large array of unipolar nanodevices, known as the self-switching diodes (SSDs). The large array was realized in a single lithography step without the need of interconnection layers, hence allowing for a simple and low-cost fabrication process. The SSD array was coupled with a narrowband dipole antenna with a resonant frequency of 890 MHz, to form a simple rectenna (rectifying antenna). The extrinsic voltage responsivity and noise-equivalent-power (NEP) of the rectenna were ∼70 V/W and ∼0.18 nW/Hz1/2, respectively, measured in the far-field region at unbiased condition. Nevertheless, the estimated intrinsic voltage responsivity can achieve up to ∼5 kV/W with NEP of ∼2.6 pW/Hz1/2.

Identification of combinatorial host-specific signatures with a potential to affect host adaptation in influenza A H1N1 and H3N2 subtypes.

PubMed

Khaliq, Zeeshan; Leijon, Mikael; Belák, Sándor; Komorowski, Jan

2016-07-29

The underlying strategies used by influenza A viruses (IAVs) to adapt to new hosts while crossing the species barrier are complex and yet to be understood completely. Several studies have been published identifying singular genomic signatures that indicate such a host switch. The complexity of the problem suggested that in addition to the singular signatures, there might be a combinatorial use of such genomic features, in nature, defining adaptation to hosts. We used computational rule-based modeling to identify combinatorial sets of interacting amino acid (aa) residues in 12 proteins of IAVs of H1N1 and H3N2 subtypes. We built highly accurate rule-based models for each protein that could differentiate between viral aa sequences coming from avian and human hosts. We found 68 host-specific combinations of aa residues, potentially associated to host adaptation on HA, M1, M2, NP, NS1, NEP, PA, PA-X, PB1 and PB2 proteins of the H1N1 subtype and 24 on M1, M2, NEP, PB1 and PB2 proteins of the H3N2 subtypes. In addition to these combinations, we found 132 novel singular aa signatures distributed among all proteins, including the newly discovered PA-X protein, of both subtypes. We showed that HA, NA, NP, NS1, NEP, PA-X and PA proteins of the H1N1 subtype carry H1N1-specific and HA, NA, PA-X, PA, PB1-F2 and PB1 of the H3N2 subtype carry H3N2-specific signatures. M1, M2, PB1-F2, PB1 and PB2 of H1N1 subtype, in addition to H1N1 signatures, also carry H3N2 signatures. Similarly M1, M2, NP, NS1, NEP and PB2 of H3N2 subtype were shown to carry both H3N2 and H1N1 host-specific signatures (HSSs). To sum it up, we computationally constructed simple IF-THEN rule-based models that could distinguish between aa sequences of avian and human IAVs. From the rules we identified HSSs having a potential to affect the adaptation to specific hosts. The identification of combinatorial HSSs suggests that the process of adaptation of IAVs to a new host is more complex than previously suggested

Absolute Measurements of Macrophage Migration Inhibitory Factor and Interleukin-1-β mRNA Levels Accurately Predict Treatment Response in Depressed Patients.

PubMed

Cattaneo, Annamaria; Ferrari, Clarissa; Uher, Rudolf; Bocchio-Chiavetto, Luisella; Riva, Marco Andrea; Pariante, Carmine M

2016-10-01

Increased levels of inflammation have been associated with a poorer response to antidepressants in several clinical samples, but these findings have had been limited by low reproducibility of biomarker assays across laboratories, difficulty in predicting response probability on an individual basis, and unclear molecular mechanisms. Here we measured absolute mRNA values (a reliable quantitation of number of molecules) of Macrophage Migration Inhibitory Factor and interleukin-1β in a previously published sample from a randomized controlled trial comparing escitalopram vs nortriptyline (GENDEP) as well as in an independent, naturalistic replication sample. We then used linear discriminant analysis to calculate mRNA values cutoffs that best discriminated between responders and nonresponders after 12 weeks of antidepressants. As Macrophage Migration Inhibitory Factor and interleukin-1β might be involved in different pathways, we constructed a protein-protein interaction network by the Search Tool for the Retrieval of Interacting Genes/Proteins. We identified cutoff values for the absolute mRNA measures that accurately predicted response probability on an individual basis, with positive predictive values and specificity for nonresponders of 100% in both samples (negative predictive value=82% to 85%, sensitivity=52% to 61%). Using network analysis, we identified different clusters of targets for these 2 cytokines, with Macrophage Migration Inhibitory Factor interacting predominantly with pathways involved in neurogenesis, neuroplasticity, and cell proliferation, and interleukin-1β interacting predominantly with pathways involved in the inflammasome complex, oxidative stress, and neurodegeneration. We believe that these data provide a clinically suitable approach to the personalization of antidepressant therapy: patients who have absolute mRNA values above the suggested cutoffs could be directed toward earlier access to more assertive antidepressant strategies

Neutral endopeptidase (EC 3.4.24.11) downregulates the onset of intestinal inflammation in the nematode infected mouse

PubMed Central

Barbara, G; De Giorgio, R; Stanghellini, V; Corinaldesi, R; Cremon, C; Gerard, N; Gerard, C; Grady, E F; Bunnett, N W; Blennerhassett, P A; Collins, S M

2003-01-01

Background and aims: Substance P (SP) release from sensory nerves induces neurogenic inflammation. Neutral endopeptidase (NEP) degrades SP, thereby limiting its proinflammatory effects. Intestinal inflammation following Trichinella spiralis infection markedly downregulates NEP, resulting in diminished SP degradation, with unknown functional consequences. We hypothesised that diminished expression of NEP would exacerbate T spiralis induced enteritis. Methods: NEP knockout (NEP−/−) and wild-type (NEP+/+) mice were infected with T spiralis and studied at 6, 12, 24, and 48 hours post infection (PI). Tissue inflammation was quantified by computerised cell counting and myeloperoxidase activity (MPO). The leucocyte adhesion molecule, intercellular adhesion molecule 1 (ICAM-1), and SP were assessed by immunohistochemistry. Results: Before infection, the lack of NEP was not associated with changes in mucosal cellularity or MPO activity. Twelve hours PI, NEP−/− mice showed a 2.5-fold increase in MPO activity at a time when values in NEP+/+ mice were still within normal limits. MPO activity and cellularity peaked at 24 hours PI. This was accompanied by increased staining for both ICAM-1 and SP in NEP−/− mice. Infusion of rhNEP to NEP−/− mice significantly reduced MPO activity 24 hours PI. Conclusions: These findings demonstrate that NEP downregulates the early onset of nematode intestinal inflammation and that increased bioavailability of SP and overexpression of ICAM-1 in NEP−/− mice likely play a role in the earlier onset of intestinal inflammation. PMID:12970139

Casein kinase 2 and the cell response to growth factors.

PubMed

Filhol-Cochet, O; Loue-Mackenbach, P; Cochet, C; Chambaz, E M

1994-01-01

Different approaches have been followed with the aim of delineating a possible role of casein kinase 2 (CK2) in the mitogenic signalling in response to cell growth factors. (a) Immunocytochemical detection of CK2 showed that while the kinase is evenly distributed throughout cycle arrested cells, it becomes preferentially associated with the nuclear compartment in activity growing cells; (b) CK2 biosynthesis is activated as an early response of quiescent cells to growth factors. The newly synthesized CK2 steadily accumulates as the cells progress through the G1 phase. This growth factor-induced CK2 biosynthesis involves in parallel the two alpha and beta subunits of the kinase, with no detectable preferential subcellular localization of the newly synthesized enzyme; and (c) In addition to substrate phosphorylation, CK2 may form molecular complexes with cell components of functional significance. Such is the case with the protein p53, a major negative regulator of the cell cycle. CK2 forms a high affinity association (Kd 70 nM) with p53, through its beta subunit. The complex dissociates in the presence of adenosine triphosphate (ATP). These observations suggest that CK2 and p53 may play a coordinated regulatory role in the cell response to growth factors.

Bayes Factor Covariance Testing in Item Response Models.

PubMed

Fox, Jean-Paul; Mulder, Joris; Sinharay, Sandip

2017-12-01

Two marginal one-parameter item response theory models are introduced, by integrating out the latent variable or random item parameter. It is shown that both marginal response models are multivariate (probit) models with a compound symmetry covariance structure. Several common hypotheses concerning the underlying covariance structure are evaluated using (fractional) Bayes factor tests. The support for a unidimensional factor (i.e., assumption of local independence) and differential item functioning are evaluated by testing the covariance components. The posterior distribution of common covariance components is obtained in closed form by transforming latent responses with an orthogonal (Helmert) matrix. This posterior distribution is defined as a shifted-inverse-gamma, thereby introducing a default prior and a balanced prior distribution. Based on that, an MCMC algorithm is described to estimate all model parameters and to compute (fractional) Bayes factor tests. Simulation studies are used to show that the (fractional) Bayes factor tests have good properties for testing the underlying covariance structure of binary response data. The method is illustrated with two real data studies.

Familial factors responsible for persistent crying-induced asthma: a case report.

PubMed

Weinstein, A G

1987-10-01

Crying behavior of the asthmatic child may induce wheezing symptoms. This may be a clinical problem for families with asthmatic children who exhibit frequent and persistent crying behavior. This case report identifies behaviors by the child and parents that may be responsible for continual crying. Child factors include (1) "spoiled" personality, (2) poor self-image, (3) biologic sensitivity to foods, medication, and environmental allergens producing irritability. Parental factors include poor disciplinary practices secondary to (1) disrupted home life, (2) guilt, and (3) overprotective behavior. Identification of these factors may be helpful in establishing clinical management strategies to reduce crying-induced asthma.

Effects of Nuclear Factor-E2-related factor 2/Heme Oxygenase 1 on splanchnic hemodynamics in experimental cirrhosis with portal hypertension.

PubMed

Qin, Jun; He, Yue; Duan, Ming; Luo, Meng

2017-05-01

We explored the effects of Nuclear Factor-E2-related factor 2 (Nrf2) and Heme Oxygenase 1 (HO-1) on splanchnic hemodynamics in portal hypertensive rats. Experimental cirrhosis with portal hypertension was induced by intraperitoneal injection of carbon tetrachloride. The expression of proteins was examined by immunoblotting. Hemodynamic studies were performed by radioactive microspheres. The vascular perfusion system was used to measure the contractile response of mesentery arterioles in rats. Nrf2 expression in the nucleus and HO-1 expression in cytoplasm was significantly enhanced in portal hypertensive rats. Portal pressure, as well as regional blood flow, increased significantly in portal hypertension and can be blocked by tin protoporphyrin IX. The expression of endogenous nitric oxide synthase and vascular endothelial growth factors increased significantly compared to normal rats, while HO-1 inhibition decreased the expression of these proteins significantly. The contractile response of mesenteric arteries decreased in portal hypertension, but can be partially recovered through tin protoporphyrin IX treatment. The expression of Nrf2/HO-1 increased in mesenteric arteries of portal hypertensive rats, which was related to oxidative stress. HO-1was involved in increased portal pressure and anomaly splanchnic hemodynamics in portal hypertensive rats. Copyright © 2016 Elsevier Inc. All rights reserved.

Profound loss of neprilysin accompanied by decreased levels of neuropeptides and increased CRP in ulcerative colitis.

PubMed

Sargın, Zeynep Gök; Erin, Nuray; Tazegul, Gokhan; Elpek, Gülsüm Özlem; Yıldırım, Bülent

2017-01-01

Neprilysin (NEP, CD10) acts to limit excessive inflammation partly by hydrolyzing neuropeptides. Although deletion of NEP exacerbates intestinal inflammation in animal models, its role in ulcerative colitis (UC) is not well explored. Herein, we aimed to demonstrate changes in NEP and associated neuropeptides at the same time in colonic tissue. 72 patients with UC and 27 control patients were included. Patients' demographic data and laboratory findings, five biopsy samples from active colitis sites and five samples from uninvolved mucosa were collected. Substance P (SP), calcitonin gene related peptide (CGRP) and vasoactive intestinal peptide (VIP) were extracted from freshly frozen tissues and measured using ELISA. Levels of NEP expression were determined using immunohistochemistry and immunoreactivity scores were calculated. GEBOES grading system was also used. We demonstrated a profound loss (69.4%) of NEP expression in UC, whereas all healthy controls had NEP expression. Patients with UC had lower neuronal SP; however non-neuronal SP remained similar. UC patients had also lower neuronal and non-neuronal VIP levels. CGRP were low in general and no significant changes were observed. Additionally, CRP positive patients with UC had higher rates of NEP loss (80% vs 51.9%) and lower SP levels when compared with CRP negative patients with UC. Concurrent decreases in SP and VIP with profound loss of NEP expression observed in UC is likely to be one of the factors in pathogenesis. Further studies are required to define the role of neuropeptides and NEP in UC.

Profound loss of neprilysin accompanied by decreased levels of neuropeptides and increased CRP in ulcerative colitis

PubMed Central

Sargın, Zeynep Gök; Tazegul, Gokhan; Elpek, Gülsüm Özlem; Yıldırım, Bülent

2017-01-01

Neprilysin (NEP, CD10) acts to limit excessive inflammation partly by hydrolyzing neuropeptides. Although deletion of NEP exacerbates intestinal inflammation in animal models, its role in ulcerative colitis (UC) is not well explored. Herein, we aimed to demonstrate changes in NEP and associated neuropeptides at the same time in colonic tissue. 72 patients with UC and 27 control patients were included. Patients’ demographic data and laboratory findings, five biopsy samples from active colitis sites and five samples from uninvolved mucosa were collected. Substance P (SP), calcitonin gene related peptide (CGRP) and vasoactive intestinal peptide (VIP) were extracted from freshly frozen tissues and measured using ELISA. Levels of NEP expression were determined using immunohistochemistry and immunoreactivity scores were calculated. GEBOES grading system was also used. We demonstrated a profound loss (69.4%) of NEP expression in UC, whereas all healthy controls had NEP expression. Patients with UC had lower neuronal SP; however non-neuronal SP remained similar. UC patients had also lower neuronal and non-neuronal VIP levels. CGRP were low in general and no significant changes were observed. Additionally, CRP positive patients with UC had higher rates of NEP loss (80% vs 51.9%) and lower SP levels when compared with CRP negative patients with UC. Concurrent decreases in SP and VIP with profound loss of NEP expression observed in UC is likely to be one of the factors in pathogenesis. Further studies are required to define the role of neuropeptides and NEP in UC. PMID:29232715

The bZIP Transcription Factor Fgap1 Mediates Oxidative Stress Response and Trichothecene Biosynthesis But Not Virulence in Fusarium graminearum

PubMed Central

Montibus, Mathilde; Ducos, Christine; Bonnin-Verdal, Marie-Noelle; Bormann, Jorg; Ponts, Nadia; Richard-Forget, Florence; Barreau, Christian

2013-01-01

Redox sensing is of primary importance for fungi to cope with oxidant compounds found in their environment. Plant pathogens are particularly subject to the oxidative burst during the primary steps of infection. In the budding yeast Saccharomyces cerevisiae, it is the transcription factor Yap1 that mediates the response to oxidative stress via activation of genes coding for detoxification enzymes. In the cereal pathogen Fusarium graminearum, Fgap1 a homologue of Yap1 was identified and its role was investigated. During infection, this pathogen produces mycotoxins belonging to the trichothecenes family that accumulate in the grains. The global regulation of toxin biosynthesis is not completely understood. However, it is now clearly established that an oxidative stress activates the production of toxins by F. graminearum. The involvement of Fgap1 in this activation was investigated. A deleted mutant and a strain expressing a truncated constitutive form of Fgap1 were constructed. None of the mutants was affected in pathogenicity. The deleted mutant showed higher level of trichothecenes production associated with overexpression of Tri genes. Moreover activation of toxin accumulation in response to oxidative stress was no longer observed. Regarding the mutant with the truncated constitutive form of Fgap1, toxin production was strongly reduced. Expression of oxidative stress response genes was not activated in the deleted mutant and expression of the gene encoding the mitochondrial superoxide dismutase MnSOD1 was up-regulated in the mutant with the truncated constitutive form of Fgap1. Our results demonstrate that Fgap1 plays a key role in the link between oxidative stress response and F. graminearum secondary metabolism. PMID:24349499

Relationship among circulating anti-Müllerian hormone, insulin like growth factor 1, cadmium and superovulatory response in dairy cows.

PubMed

Abdel Aziz, R L; Khalil, A A Y; Abdel-Wahab, A; Hassan, N Y; Abdel-Hamied, E; Kasimanickam, R K

2017-09-15

The objectives of this study were 1. to determine the associations among circulating anti-Mullerian hormone (AMH), insulin like growth factor 1 (IGF1) and cadmium (Cd) concentrations of lactating Holstein cows at the time of superovulation and 2. to determine the effect of circulating AMH, IGF1 and Cd concentrations on the superovulatory response in Holstein dairy cows. Holstein cows (n = 30) were milked thrice daily and housed and fed in free stall barn as a separate group. All animals were synchronized for superovulation and flushed. Three blood samples for AMH, IGF1 and Cd analysis were collected prior to superovulation, at estrus and at the time of embryo collection. The concentrations of blood makers prior to superovulation were highly correlated to superovulatory response. Circulating concentrations of AMH, IGF1 prior to superovulation were negatively correlated to Cd concentrations (P < 0.05). There was no correlation between circulating concentrations of AMH and IGF1. The number of corpus luteum (r = 0.71), total embryo (r = 0.67), total transferable embryo (r = 0.51) and total grade 1 embryo (r = 0.5) were positively correlated to AMH concentrations (P < 0.05). There was a trend for negative correlation found between circulating cadmium concentrations and total grade 1 embryo yield (P < 0.1). When cows were classified into quartiles (Q) of circulating AMH concentration, number of corpus luteum, and total embryos, total transferable embryos and total grade 1 embryos yield was significantly different for AMH quartiles. The superovulatory response parameters evaluated were increased with increased AMH concentrations; particularly we observed a >2-fold difference between first and fourth AMH quartiles in total transferable embryo yield and total grade 1 embryo yield. In conclusion, circulating AMH concentration was strongly associated with superovulatory response. Measuring AMH before enrolling cows in superovulation programs will likely allow

Drought-responsive WRKY transcription factor genes TaWRKY1 and TaWRKY33 from wheat confer drought and/or heat resistance in Arabidopsis.

PubMed

He, Guan-Hua; Xu, Ji-Yuan; Wang, Yan-Xia; Liu, Jia-Ming; Li, Pan-Song; Chen, Ming; Ma, You-Zhi; Xu, Zhao-Shi

2016-05-23

Drought stress is one of the major causes of crop loss. WRKY transcription factors, as one of the largest transcription factor families, play important roles in regulation of many plant processes, including drought stress response. However, far less information is available on drought-responsive WRKY genes in wheat (Triticum aestivum L.), one of the three staple food crops. Forty eight putative drought-induced WRKY genes were identified from a comparison between de novo transcriptome sequencing data of wheat without or with drought treatment. TaWRKY1 and TaWRKY33 from WRKY Groups III and II, respectively, were selected for further investigation. Subcellular localization assays revealed that TaWRKY1 and TaWRKY33 were localized in the nuclei in wheat mesophyll protoplasts. Various abiotic stress-related cis-acting elements were observed in the promoters of TaWRKY1 and TaWRKY33. Quantitative real-time PCR (qRT-PCR) analysis showed that TaWRKY1 was slightly up-regulated by high-temperature and abscisic acid (ABA), and down-regulated by low-temperature. TaWRKY33 was involved in high responses to high-temperature, low-temperature, ABA and jasmonic acid methylester (MeJA). Overexpression of TaWRKY1 and TaWRKY33 activated several stress-related downstream genes, increased germination rates, and promoted root growth in Arabidopsis under various stresses. TaWRKY33 transgenic Arabidopsis lines showed lower rates of water loss than TaWRKY1 transgenic Arabidopsis lines and wild type plants during dehydration. Most importantly, TaWRKY33 transgenic lines exhibited enhanced tolerance to heat stress. The functional roles highlight the importance of WRKYs in stress response.

ABFs, a family of ABA-responsive element binding factors.

PubMed

Choi, H; Hong, J; Ha, J; Kang, J; Kim, S Y

2000-01-21

Abscisic acid (ABA) plays an important role in environmental stress responses of higher plants during vegetative growth. One of the ABA-mediated responses is the induced expression of a large number of genes, which is mediated by cis-regulatory elements known as abscisic acid-responsive elements (ABREs). Although a number of ABRE binding transcription factors have been known, they are not specifically from vegetative tissues under induced conditions. Considering the tissue specificity of ABA signaling pathways, factors mediating ABA-dependent stress responses during vegetative growth phase may thus have been unidentified so far. Here, we report a family of ABRE binding factors isolated from young Arabidopsis plants under stress conditions. The factors, isolated by a yeast one-hybrid system using a prototypical ABRE and named as ABFs (ABRE binding factors) belong to a distinct subfamily of bZIP proteins. Binding site selection assay performed with one ABF showed that its preferred binding site is the strong ABRE, CACGTGGC. ABFs can transactivate an ABRE-containing reporter gene in yeast. Expression of ABFs is induced by ABA and various stress treatments, whereas their induction patterns are different from one another. Thus, a new family of ABRE binding factors indeed exists that have the potential to activate a large number of ABA/stress-responsive genes in Arabidopsis.

The Role of Factor Inhibiting HIF (FIH-1) in Inhibiting HIF-1 Transcriptional Activity in Glioblastoma Multiforme

PubMed Central

Liu, Fengming; Wu, Gang; Schroeder, Mark A.; Lau, Julie S.; Mukhopadhyay, Debabrata; Jiang, Shi-Wen; O'Neill, Brian Patrick; Datta, Kaustubh; Li, Jinping

2014-01-01

Glioblastoma multiforme (GBM) accounts for about 38% of primary brain tumors in the United States. GBM is characterized by extensive angiogenesis induced by vascular growth factors and cytokines. The transcription of these growth factors and cytokines is regulated by the Hypoxia-Inducible-Factor-1(HIF-1), which is a key regulator mediating the cellular response to hypoxia. It is known that Factor Inhibiting HIF-1, or FIH-1, is also involved in the cellular response to hypoxia and has the capability to physically interact with HIF-1 and block its transcriptional activity under normoxic conditions. Delineation of the regulatory role of FIH-1 will help us to better understand the molecular mechanism responsible for tumor growth and progression and may lead to the design of new therapies targeting cellular pathways in response to hypoxia. Previous studies have shown that the chromosomal region of 10q24 containing the FIH-1 gene is often deleted in GBM, suggesting a role for the FIH-1 in GBM tumorigenesis and progression. In the current study, we found that FIH-1 is able to inhibit HIF-mediated transcription of GLUT1 and VEGF-A, even under hypoxic conditions in human glioblastoma cells. FIH-1 has been found to be more potent in inhibiting HIF function than PTEN. This observation points to the possibility that deletion of 10q23-24 and loss or decreased expression of FIH-1 gene may lead to a constitutive activation of HIF-1 activity, an alteration of HIF-1 targets such as GLUT-1 and VEGF-A, and may contribute to the survival of cancer cells in hypoxia and the development of hypervascularization observed in GBM. Therefore FIH-1 can be potential therapeutic target for the treatment of GBM patients with poor prognosis. PMID:24465898

Competition of nuclear factor-erythroid 2 factors related transcription factor isoforms, Nrf1 and Nrf2, in antioxidant enzyme induction☆

PubMed Central

Chepelev, Nikolai L.; Zhang, Hongqiao; Liu, Honglei; McBride, Skye; Seal, Andrew J.; Morgan, Todd E.; Finch, Caleb E.; Willmore, William G.; Davies, Kelvin J.A.; Forman, Henry Jay

2013-01-01

Although the Nrf2 (nuclear factor-erythroid 2 p45 subunit-related factor 2) regulated expression of multiple antioxidant and cytoprotective genes through the electrophile responsive element (EpRE) is well established, interaction of Nrf2/EpRE with Nrf1, a closely-related transcription factor, is less well understood. Due to either proteolysis or alternative translation, Nrf1 has been found as proteins of varying size, p120, p95, and p65, which have been described as either activators of EpRE or competitive inhibitors of Nrf2. We investigated the effect of Nrf1 on EpRE-regulated gene expression using the catalytic and modifier subunits of glutamate cysteine ligase (GCLC and GCLM) as models and explored the potential role of Nrf1 in altering their expression in aging and upon chronic exposure to airborne nano-sized particulate matter (nPM). Nrf1 knockout resulted in the increased expression of GCLC and GCLM in human bronchial epithelial (HBE1) cells. Overexpression Nrf2 in combination with either p120 or p65 diminished or failed to further increase the GCLC- and GLCM-EpRE luciferase activity. All known forms of Nrf1 protein, remained unchanged in the lungs of mice with age or in response to nPM. Our study shows that Nrf1 could inhibit EpRE activity in vitro, whereas the precise role of Nrf1 in vivo requires further investigations. We conclude that Nrf1 may not be directly responsible for the loss of Nrf2-dependent inducibility of antioxidant and cytoprotective genes observed in aged animals. PMID:24024152

Induction of Sirt1 by Mechanical Stretch of Skeletal Muscle through the Early Response Factor EGR1 Triggers an Antioxidative Response*

PubMed Central

Pardo, Patricia S.; Mohamed, Junaith S.; Lopez, Michael A.; Boriek, Aladin M.

2011-01-01

Mechanical loading of muscles by intrinsic muscle activity or passive stretch leads to an increase in the production of reactive oxygen species (1, 2). The NAD-dependent protein deacetylase SIRT1 is involved in the protection against oxidative stress by enhancing FOXO-driven Sod2 transcription (3–5). In this report, we unravel a mechanism triggered by mechanical stretch of skeletal muscle cells that leads to an EGR1-dependent transcriptional activation of the Sirt1 gene. The resulting transient increase in SIRT1 expression generates an antioxidative response that contributes to reactive oxygen species scavenging. PMID:20971845

Identification of a DNA-binding site for the transcription factor Haa1, required for Saccharomyces cerevisiae response to acetic acid stress

PubMed Central

Mira, Nuno P.; Henriques, Sílvia F.; Keller, Greg; Teixeira, Miguel C.; Matos, Rute G.; Arraiano, Cecília M.; Winge, Dennis R.; Sá-Correia, Isabel

2011-01-01

The transcription factor Haa1 is the main player in reprogramming yeast genomic expression in response to acetic acid stress. Mapping of the promoter region of one of the Haa1-activated genes, TPO3, allowed the identification of an acetic acid responsive element (ACRE) to which Haa1 binds in vivo. The in silico analysis of the promoter regions of the genes of the Haa1-regulon led to the identification of an Haa1-responsive element (HRE) 5′-GNN(G/C)(A/C)(A/G)G(A/G/C)G-3′. Using surface plasmon resonance experiments and electrophoretic mobility shift assays it is demonstrated that Haa1 interacts with high affinity (KD of 2 nM) with the HRE motif present in the ACRE region of TPO3 promoter. No significant interaction was found between Haa1 and HRE motifs having adenine nucleotides at positions 6 and 8 (KD of 396 and 6780 nM, respectively) suggesting that Haa1p does not recognize these motifs in vivo. A lower affinity of Haa1 toward HRE motifs having mutations in the guanine nucleotides at position 7 and 9 (KD of 21 and 119 nM, respectively) was also observed. Altogether, the results obtained indicate that the minimal functional binding site of Haa1 is 5′-(G/C)(A/C)GG(G/C)G-3′. The Haa1-dependent transcriptional regulatory network active in yeast response to acetic acid stress is proposed. PMID:21586585

The parkin Mutant Phenotype in the Fly Is Largely Rescued by Metal-Responsive Transcription Factor (MTF-1) ▿ †

PubMed Central

Saini, Nidhi; Georgiev, Oleg; Schaffner, Walter

2011-01-01

The gene for Parkin, an E3 ubiquitin ligase, is mutated in some familial forms of Parkinson's disease, a severe neurodegenerative disorder. A homozygous mutant of the Drosophila ortholog of human parkin is viable but results in severe motoric impairment including an inability to fly, female and male sterility, and a decreased life span. We show here that a double mutant of the genes for Parkin and the metal-responsive transcription factor 1 (MTF-1) is not viable. MTF-1, which is conserved from insects to mammals, is a key regulator of heavy metal homeostasis and detoxification and plays additional roles in other stress conditions, notably oxidative stress. In contrast to the synthetic lethality of the double mutant, elevated expression of MTF-1 dramatically ameliorates the parkin mutant phenotype, as evidenced by a prolonged life span, motoric improvement including short flight episodes, and female fertility. At the cellular level, muscle and mitochondrial structures are substantially improved. A beneficial effect is also seen with a transgene encoding human MTF-1. We propose that Parkin and MTF-1 provide complementary functions in metal homeostasis, oxidative stress and other cellular stress responses. Our findings also raise the possibility that MTF-1 gene polymorphisms in humans could affect the severity of Parkinson's disease. PMID:21383066

Effect of National Football League games on small animal emergency room caseload.

PubMed

Rozanski, Elizabeth A; Rondeau, Mark P; Shaw, Scott P; Rush, John E

2009-07-01

To evaluate whether games of popular professional football teams have an effect on small animal emergency room caseload and percentage of dogs and cats that subsequently are hospitalized, are euthanatized, or die following admission to veterinary emergency rooms located within a dedicated fan base. Prospective study. 818 dogs and cats admitted to the emergency room. During the 2007 New England Patriots (NEP) football season, small animal emergency room caseload was recorded for Sunday (4-hour blocks, 8:00 AM until 12:00 midnight) and Monday night (7:00 PM to 11:00 PM). Number of dogs and cats that subsequently were hospitalized, died, or were euthanatized was recorded. Mean game importance rating (GIR) was determined for NEP games (scale, 1 [mild] to 3 [great]). Percentage of dogs and cats admitted from 12:00 noon to 4:00 PM on Sundays during NEP games (mean GIR, 1.7) versus non-NEP games was not different. Mean +/- SD percentage of dogs and cats admitted from 4:00 PM to 8:00 PM on Sundays during NEP games (mean GIR, 2.4) versus non-NEP games was significantly different (18 +/- 5% and 25 +/- 7% of daily caseload, respectively). Percentage of dogs and cats admitted from 8:00 PM to 12:00 midnight on Sundays during NEP games (mean GIR, 2.1) versus non-NEP games was not different. Game type (NEP vs non-NEP) during emergency room admission did not influence whether dogs and cats subsequently were hospitalized, died, or were euthanatized. Professional sporting events may influence veterinary emergency room caseloads.

Specific memory B cell response and participation of CD4+ central and effector memory T cells in mice immunized with liposome encapsulated recombinant NE protein based Hepatitis E vaccine candidate.

PubMed

Kulkarni, Shruti P; Thanapati, Subrat; Arankalle, Vidya A; Tripathy, Anuradha S

2016-11-21

Liposome encapsulated neutralizing epitope protein of Hepatitis E virus (HEV), rNEp, our Hepatitis E vaccine candidate, was shown to be immunogenic and safe in pregnant and non-pregnant mice and yielded sterilizing immunity in rhesus monkeys. The current study in Balb/c mice assessed the levels and persistence of anti-HEV IgG antibodies by ELISA, frequencies of B, memory B, T and memory T cells by flow cytometry and HEV-specific IgG secreting memory B cells by ELISPOT till 420days post immunization (PI) with 5?g rNEp encapsulated in liposome based adjuvant (2 doses, 4weeks apart). Mice immunized with a lower dose (1?g) were assessed only for anamnestic response post booster dose. Vaccine candidate immunized mice (5?g dose) elicited strong anti-HEV IgG response that was estimated to persist for lifetime. At day 120 PI, frequency of memory B cells was higher in immunized mice than those receiving adjuvant alone. Anti-HEV IgG titers were lower in mice immunized with 1?g dose. A booster dose yielded a heightened antibody response in mice with both high (>800GMT, 5?g) and low (?100GMT, 1?g) anti-HEV IgG titers. At day 6th post booster dose, HEV-specific antibody secreting plasma cells (ASCs) were detected in 100% and 50% of mice with high and low anti-HEV IgG titers, respectively, whereas the frequencies of CD4 + central and effector memory T cells were high in mice with high anti-HEV IgG titers only. Taken together, the vaccine candidate effectively generates persistent and anamnestic antibody response, elicits participation of CD4 + memory T cells and triggers memory B cells to differentiate into ASCs upon boosting. This approach of assessing the immunogenicity of vaccine candidate could be useful to explore the longevity of HEV-specific memory response in future HEV vaccine trials in human. Copyright © 2016. Published by Elsevier Ltd.

Submergence tolerance conferred by Sub1A is mediated by SLR1 and SLRL1 restriction of gibberellin responses in rice

PubMed Central

Fukao, Takeshi; Bailey-Serres, Julia

2008-01-01

Submergence-tolerant rice maintains viability during complete submergence by limiting underwater elongation until floodwaters recede. Acclimation responses to submergence are coordinated by the submergence-inducible Sub1A, which encodes an ethylene-responsive factor-type transcription factor (ERF). Sub1A is limited to tolerant genotypes and sufficient to confer submergence tolerance to intolerant accessions. Here we evaluated the role of Sub1A in the integration of ethylene, abscisic acid (ABA), and gibberellin (GA) signaling during submergence. The submergence-stimulated decrease in ABA content was Sub1A-independent, whereas GA-mediated underwater elongation was significantly restricted by Sub1A. Transgenics that ectopically express Sub1A displayed classical GA-insensitive phenotypes, leading to the hypothesis that Sub1A limits the response to GA. Notably Sub1A increased the accumulation of the GA signaling repressors Slender Rice-1 (SLR1) and SLR1 Like-1 (SLRL1) and concomitantly diminished GA-inducible gene expression under submerged conditions. In the Sub1A overexpression line, SLR1 protein levels declined under prolonged submergence but were accompanied by an increase in accumulation of SLRL1, which lacks the DELLA domain. In the presence of Sub1A, the increase in these GA signaling repressors and decrease in GA responsiveness were stimulated by ethylene, which promotes Sub1A expression. Conversely, ethylene promoted GA responsiveness and shoot elongation in submergence-intolerant lines. Together, these results demonstrate that Sub1A limits ethylene-promoted GA responsiveness during submergence by augmenting accumulation of the GA signaling repressors SLR1 and SLRL1. PMID:18936491

Soluble vascular endothelial growth factor (VEGF) receptor-1 inhibits migration of human monocytic THP-1 cells in response to VEGF.

PubMed

Zhu, Cansheng; Xiong, Zhaojun; Chen, Xiaohong; Lu, Zhengqi; Zhou, Guoyu; Wang, Dunjing; Bao, Jian; Hu, Xueqiang

2011-08-01

We aimed to investigate the regulation and contribution of vascular endothelial growth factor (VEGF) and sFlt-1(1-3) to human monocytic THP-1 migration. Ad-sFlt-1/FLAG, a recombinant adenovirus carrying the human sFlt-1(1-3) (the first three extracellular domains of FLT-1, the hVEGF receptor-1) gene, was constructed. L929 cells were infected with Ad-sFlt-1/FLAG and the expression of sFlt-1 was detected by immunofluorescent assay and ELISA. Corning(®) Transwell(®) Filter Inserts containing polyethylene terephthalate (PET) membranes with pore sizes of 3 μm were used as an experimental model to simulate THP-1 migration. Five VEGF concentrations (0, 0.1, 1, 10 and 100 ng/ml), four concentrations of sFlt-1(1-3)/FLAG expression supernatants (0.1, 1, 10 and 100 ng/ml), and monocyte chemoattractant protein-1 (MCP-1, 10 ng/ml) were used to test the ability of THP-1 cells to migrate through PET membranes. The sFlt-1(1-3) gene was successfully recombined into Ad-sFlt-1/FLAG. sFlt-1(1-3) was expressed in L929 cells transfected with Ad-sFlt-1/FLAG. THP-1 cell migration increased with increasing concentrations of VEGF, while cell migration decreased with increasing concentrations of sFlt1(1-3)/FLAG. sFlt1(1-3)/FLAG had no effect on MCP-1-induced cell migration. This study demonstrated that VEGF is able to elicit a migratory response in THP-1 cells, and that sFlt-1(1-3) is an effective inhibitor of THP-1 migration towards VEGF.

Optimization of narrow width effect on titanium thermistor in uncooled antenna-coupled terahertz microbolometer

NASA Astrophysics Data System (ADS)

Banerjee, Amit; Satoh, Hiroaki; Elamaran, Durgadevi; Sharma, Yash; Hiromoto, Norihisa; Inokawa, Hiroshi

2018-04-01

Uncooled antenna-coupled terahertz microbolometer arrays are fabricated with a meander-type Ti thermistor, and design widths (DW) = 0.1 and 0.2 µm, considering the design requirement to miniaturize detectors. Each unit device with DW = 0.1 µm of the thermistor has about 4.7 time higher electrical responsivity (132 V/W) than that with DW = 0.2 µm (28.2 V/W) at 10 µA bias current. For DW = 0.2 µm, the calculated noise equivalent power (NEP) was 2.29 × 10‑9 W/\\sqrt{\\text{Hz}} , whereas the minimum NEP of 4.43 × 10‑10 W/\\sqrt{\\text{Hz}} was obtained for DW = 0.1 µm devices, both at 10 µA bias current. The bulk value of temperature coefficient of resistance (TCR) of the Ti thermistor is markedly compromised in low dimensional devices, still in terms of responsivity and NEP, unit devices with Ti thermistor with the lower DW shows better performance. This is because the narrow width effect is minimized owing to higher resistivity for DW = 0.1 than that for DW = 0.2 µm. In this current report, we highlights the optimization of the narrow width effect on TCR of metal interconnects in nanometer dimensions, which to the best of our knowledge is not available at present.

Effects of aerosolised substance P on lung resistance in guinea-pigs: a comparison between inhibition of neutral endopeptidase and angiotensin-converting enzyme.

PubMed

Lötvall, J O; Skoogh, B E; Barnes, P J; Chung, K F

1990-05-01

1. We have examined in guinea-pigs, in vivo, the effects of inhibition of neutral endopeptidase (NEP) and angiotensin-converting enzyme (ACE) on the airway response to aerosolised substance P (SP). We aerosolised captopril (4.6 mM, 60 breaths; 210 nmol) to inhibit ACE and acetorphan (0.3, 1 and 3 mM, 60 breaths; 9 nmol, 33 nmol and 110 nmol respectively) to inhibit NEP. We also examined the effect of the highest dose of acetorphan (110 nmol) on the response to aerosolised acetylcholine (ACh). 2. Responsiveness to SP (or ACh) was measured as the change in lung resistance (RL) induced by nebulisation of increasing concentrations of SP (or ACh) before and after treatment with the inhibitor. PC200, defined as the provocative concentration inducing an increase in RL of 200% above baseline was calculated for each challenge. 3. Administration of acetorphan before the second SP-challenge induced a dose-dependent decrease in PC200 for SP amounting to 1.8 (+/- 0.3) log units after treatment with 11 nmol acetorphan. Treatment with vehicle before the second SP-challenge or with 3 mM acetorphan before the second ACh-challenge had no significant effect on PC200. 4. Treatment with captopril (21 nmol) induced only a small, nonsignificant leftward shift of PC200 to SP (0.3 +/- 0.2 log units). 5. We conclude that a NEP-like enzyme, but not ACE, regulates the response to aerosolised SP. We suggest that the same is true for SP released endogenously from sensory nerve endings in the airway epithelial layer.

Effects of aerosolised substance P on lung resistance in guinea-pigs: a comparison between inhibition of neutral endopeptidase and angiotensin-converting enzyme.

PubMed Central

Lötvall, J. O.; Skoogh, B. E.; Barnes, P. J.; Chung, K. F.

1990-01-01

1. We have examined in guinea-pigs, in vivo, the effects of inhibition of neutral endopeptidase (NEP) and angiotensin-converting enzyme (ACE) on the airway response to aerosolised substance P (SP). We aerosolised captopril (4.6 mM, 60 breaths; 210 nmol) to inhibit ACE and acetorphan (0.3, 1 and 3 mM, 60 breaths; 9 nmol, 33 nmol and 110 nmol respectively) to inhibit NEP. We also examined the effect of the highest dose of acetorphan (110 nmol) on the response to aerosolised acetylcholine (ACh). 2. Responsiveness to SP (or ACh) was measured as the change in lung resistance (RL) induced by nebulisation of increasing concentrations of SP (or ACh) before and after treatment with the inhibitor. PC200, defined as the provocative concentration inducing an increase in RL of 200% above baseline was calculated for each challenge. 3. Administration of acetorphan before the second SP-challenge induced a dose-dependent decrease in PC200 for SP amounting to 1.8 (+/- 0.3) log units after treatment with 11 nmol acetorphan. Treatment with vehicle before the second SP-challenge or with 3 mM acetorphan before the second ACh-challenge had no significant effect on PC200. 4. Treatment with captopril (21 nmol) induced only a small, nonsignificant leftward shift of PC200 to SP (0.3 +/- 0.2 log units). 5. We conclude that a NEP-like enzyme, but not ACE, regulates the response to aerosolised SP. We suggest that the same is true for SP released endogenously from sensory nerve endings in the airway epithelial layer. PMID:1695534

Anoxia-responsive regulation of the FoxO transcription factors in freshwater turtles, Trachemys scripta elegans.

PubMed

Krivoruchko, Anastasia; Storey, Kenneth B

2013-11-01

The forkhead class O (FoxO) transcription factors are important regulators of multiple aspects of cellular metabolism. We hypothesized that activation of these transcription factors could play crucial roles in low oxygen survival in the anoxia-tolerant turtle, Trachemys scripta elegans. Two FoxOs, FoxO1 and FoxO3, were examined in turtle tissues in response to 5 and 20h of anoxic submergence using techniques of RT-PCR, western immunoblotting and DNA-binding assays to assess activation. Transcript levels of FoxO-responsive genes were also quantified using RT-PCR. FoxO1 was anoxia-responsive in the liver, with increases in transcript levels, protein levels, nuclear levels and DNA-binding of 1.7-4.8fold in response to anoxia. Levels of phosphorylated FoxO1 also decreased to 57% of control values in response to 5h of anoxia, indicating activation. FoxO3 was activated in the heart, kidney and liver in response to anoxia, with nuclear levels increasing by 1.5-3.7fold and DNA-binding activity increasing by 1.3-2.9fold. Transcript levels of two FoxO-target genes, p27kip1 and catalase, also rose by 2.4-2.5fold in the turtle liver under anoxia. The results suggest that the FoxO transcription factors are activated in response to anoxia in T. scripta elegans, potentially contributing to the regulation of stress resistance and metabolic depression. This study provides the first demonstration of activation of FoxOs in a natural model for vertebrate anoxia tolerance, further improving understanding of how tissues can survive without oxygen. © 2013.

Factors responsible for performance on the day-night task: response set or semantics?

PubMed

Simpson, Andrew; Riggs, Kevin J

2005-07-01

In a recent study Diamond, Kirkham and Amso (2002) obtained evidence consistent with the claim that the day-night task requires inhibition because the picture and its corresponding conflicting response are semantically related. In their study children responded more accurately in a dog-pig condition (see /day picture/ say "dog"; see /night picture/ say "pig") than the standard day-night condition (see /day picture/ say "night"; see /night picture/ say "day"). However, there is another effect that may have made the day-night condition harder than the dog-pig condition: the response set effect. In the day-night condition the names of the two stimuli ("day" and "night") and the two corresponding conflicting responses ("night" and "day") are from the same response set: both "day" and "night". In the dog-pig condition the names of the stimuli ("day", "night") and the corresponding responses ("dog", "pig") are from a different response set. In two experiments (Experiment 1 with 4-year-olds (n = 25); Experiment 2 with , 4-, 5-, 7- and 11-year-olds (n = 81)) children were tested on four experimental conditions that enabled the effects of semantics and response set to be separated. Overall, our data suggest that response set is a major factor in creating the inhibitory demands of the day-night task in children of all ages. Results are discussed in relation to other inhibitory tasks.

The control of microvascular permeability and blood pressure by neutral endopeptidase.

PubMed

Lu, B; Figini, M; Emanueli, C; Geppetti, P; Grady, E F; Gerard, N P; Ansell, J; Payan, D G; Gerard, C; Bunnett, N

1997-08-01

Plasma extravasation from postcapillary venules is one of the earliest steps of inflammation. Substance P (SP) and bradykinin (BK) mediate extravasation and cause hypotension. The cell-surface enzyme neutral endopeptidase (NEP) inactivates both peptides. Thus, absence of NEP may predispose development of inflammation and hypotension. We examined these possibilities in mice in which the NEP gene was deleted by homologous recombination. There was widespread basal plasma extravasation in postcapillary venular endothelia in NEP-/- mice, which was reversed by recombinant NEP and antagonists of SP (NK1) and BK (B2) receptors. Mean arterial blood pressure was 20% lower in NEP-/- animals, but this was unaffected by reintroduction of recombinant NEP and the kinin receptor antagonists. The hypotension was also independent of nitric oxide (NO), because NEP-/- mice treated with a NO synthase inhibitor remained hypotensive relative to the wild type. Thus, NEP has important roles in regulating basal microvascular permeability by degrading SP and BK, and may regulate blood pressure set point through a mechanism that is independent of SP, BK and NO. The use of NEP antagonists as candidate drugs in cardiovascular disease is suggested by the blood pressure data reported herein.

Reactive oxygen species (ROS) and the heat stress response of Daphnia pulex: ROS-mediated activation of hypoxia-inducible factor 1 (HIF-1) and heat shock factor 1 (HSF-1) and the clustered expression of stress genes.

PubMed

Klumpen, Eva; Hoffschröer, Nadine; Zeis, Bettina; Gigengack, Ulrike; Dohmen, Elias; Paul, Rüdiger J

2017-01-01

Heat stress in ectotherms involves direct (e.g. protein damage) and/or indirect effects (temperature-induced hypoxia and ROS formation), which cause activation of the transcription factors (TF) heat shock factor 1 (HSF-1) and/or hypoxia-inducible factor 1 (HIF-1). The present study focused on the links between stress (ROS) signals, nuclear (n) and cytoplasmic (c) HSF-1/HIF-1 levels, and stress gene expression on mRNA and protein levels (e.g. heat-shock protein 90, HSP90) upon acute heat and ROS (H 2 O 2 ) stress. Acute heat stress (30°C) evoked fluctuations in ROS level. Different feeding regimens, which affected the glutathione (GSH) level, allowed altering the frequency of ROS fluctuations. Other data showed fluctuation frequency to depend also on ROS production rate. The heat-induced slow or fast ROS fluctuations (at high or low GSH levels) evoked slow or fast fluctuations in the levels of nHIF-1α, nHSF-1 and gene products (mRNAs and protein), albeit after different time delays. Time delays to ROS fluctuations were, for example,shorter for nHIF-1α than for nHSF-1 fluctuations, and nHIF-1α fluctuations preceded and nHSF-1 fluctuations followed fluctuations in HSP90 mRNA level. Cytoplasmic TF levels either changed little (cHIF-1α) or showed a steady increase (cHSF-1). Applying acute H 2 O 2 stress (at 20°C) revealed effects on nHIF-1α and mRNA levels, but no significant effects on nHSF-1 level. Transcriptome data additionally showed coordinated fluctuations of mRNA levels upon acute heat stress, involving mRNAs for HSPs and other stress proteins, with all corresponding genes carrying DNA binding motifs for HIF-1 and HSF-1. This study provided evidence for promoting effects of ROS and HIF-1 on early haemoglobin, HIF-1α and HSP90 mRNA expressions upon heat or ROS stress. The increasing cHSF-1 level likely affected nHSF-1 level and later HSP90 mRNA expression. Heat stress evoked ROS fluctuations, with this stress signal forwarded via nHIF-1 and nHSF-1

Interannual Variation in Carbon Sequestration Depends Mainly on the Carbon Uptake Period in Two Croplands on the North China Plain

PubMed Central

Bao, Xueyan; Wen, Xuefa; Sun, Xiaomin; Zhao, Fenghua; Wang, Yuying

2014-01-01

Interannual variation in plant phenology can lead to major modifications in the interannual variation of net ecosystem production (NEP) and net biome production (NBP) as a result of recent climate change in croplands. Continuous measurements of carbon flux using the eddy covariance technique were conducted in two winter wheat and summer maize double-cropped croplands during 2003–2012 in Yucheng and during 2007–2012 in Luancheng on the North China Plain. Our results showed that the difference between the NEP and the NBP, i.e., the crop economic yield, was conservative even though the NEP and the NBP for both sites exhibited marked fluctuations during the years of observation. A significant and positive relationship was found between the annual carbon uptake period (CUP) and the NEP as well as the NBP. The NEP and the NBP would increase by 14.8±5.2 and 14.7±6.6 g C m−2 yr−1, respectively, if one CUP-day was extended. A positive relationship also existed between the CUP and the NEP as well as the NBP for winter wheat and summer maize, respectively. The annual air temperature, through its negative effect on the start date of the CUP, determined the length of the CUP. The spring temperature was the main indirect factor controlling the annual carbon sequestration when a one-season crop (winter wheat) was considered. Thus, global warming can be expected to extend the length of the CUP and thus increase carbon sequestration in croplands. PMID:25313713

The redox protein thioredoxin-1 (Trx-1) increases hypoxia-inducible factor 1alpha protein expression: Trx-1 overexpression results in increased vascular endothelial growth factor production and enhanced tumor angiogenesis.

PubMed

Welsh, Sarah J; Bellamy, William T; Briehl, Margaret M; Powis, Garth

2002-09-01

Hypoxia-inducible factor 1 (HIF-1), a heterodimer of HIF-1alpha and HIF-1beta subunits, is a transcriptional activator central to the cellular response to low oxygen that includes metabolic adaptation, angiogenesis, metastasis, and inhibited apoptosis. Thioredoxin-1 (Trx-1) is a small redox protein overexpressed in a number of human primary tumors. We have examined the effects of Trx-1 on HIF activity and the activation of downstream genes. Stable transfection of human breast carcinoma MCF-7 cells with human Trx-1 caused a significant increase in HIF-1alpha protein levels under both normoxic (20% oxygen) and hypoxic (1% oxygen) conditions. Trx-1 increased hypoxia-induced HIF-1 transactivation activity measured using a luciferase reporter under the control of the hypoxia response element. Changes in HIF-1alpha mRNA levels did not account for the changes observed at the protein level, and HIF-1beta protein levels did not change. Trx-1 transfection also caused a significant increase in the protein products of hypoxia-responsive genes, including vascular endothelial growth factor (VEGF) and nitric oxide synthase 2 in a number of different cell lines (MCF-7 human breast and HT29 human colon carcinomas and WEHI7.2 mouse lymphoma cells) under both normoxic and hypoxic conditions. The pattern of expression of the different isoforms of VEGF was not changed by Trx-1. Transfection of a redox-inactive Trx-1 (C32S/C35S) markedly decreased levels of HIF-1alpha protein, HIF-1 transactivating activity, and VEGF protein in MCF-7 cells compared with empty vector controls. In vivo studies using WEHI7.2 cells transfected with Trx-1 showed significantly increased tumor VEGF and angiogenesis. The results suggest that Trx-1 increases HIF-1alpha protein levels in cancer cells and increases VEGF production and tumor angiogenesis.

Increased pain and neurogenic inflammation in mice deficient of neutral endopeptidase.

PubMed

Krämer, Heidrun H; He, Lan; Lu, Bao; Birklein, Frank; Sommer, Claudia

2009-08-01

The complex regional pain syndrome (CRPS) is characterized by enhanced neurogenic inflammation, mediated by neuropeptides. Neutral endopeptidase (NEP) is a key enzyme in neuropeptide catabolism. We used NEP knock out (ko) mice to investigate whether NEP deficiency leads to increased pain behavior and signs of neurogenic inflammation after soft tissue trauma with and without nerve injury. After chronic constriction injury (CCI) of the right sciatic nerve, NEP ko mice were more sensitive to heat, to mechanical stimuli, and to cold than wild type mice. Tissue injury without nerve injury produced no differences between genotypes. After CCI, NEP ko mice showed increased hind paw edema but lower skin temperatures than wild type mice. Substance P (SP) and endothelin 1 (ET 1) determined by enzyme immuno assay (EIA) were increased in sciatic nerves from NEP ko mice after CCI. Tissue CGRP content did not differ between the genotypes. The results provide evidence that pain behavior and neurogenic inflammation are enhanced in NEP ko mice after nerve injury. These findings resemble human 'cold' CRPS and suggest that ET 1 plays an important role in the pathogenesis of CRPS with nerve injury.

Co-administration of plasmid-encoded granulocyte-macrophage colony-stimulating factor increases human immunodeficiency virus-1 DNA vaccine-induced polyfunctional CD4+ T-cell responses

PubMed Central

Santana, Vinicius Canato; Almeida, Rafael Ribeiro; Ribeiro, Susan Pereira; Ferreira, Luís Carlos de Souza; Kalil, Jorge; Rosa, Daniela Santoro; Cunha-Neto, Edecio

2015-01-01

T-cell based vaccines against human immunodeficiency virus (HIV) generate specific responses that may limit both transmission and disease progression by controlling viral load. Broad, polyfunctional, and cytotoxic CD4+T-cell responses have been associated with control of simian immunodeficiency virus/HIV-1 replication, supporting the inclusion of CD4+ T-cell epitopes in vaccine formulations. Plasmid-encoded granulocyte-macrophage colony-stimulating factor (pGM-CSF) co-administration has been shown to induce potent CD4+ T-cell responses and to promote accelerated priming and increased migration of antigen-specific CD4+ T-cells. However, no study has shown whether co-immunisation with pGM-CSF enhances the number of vaccine-induced polyfunctional CD4+ T-cells. Our group has previously developed a DNA vaccine encoding conserved, multiple human leukocyte antigen (HLA)-DR binding HIV-1 subtype B peptides, which elicited broad, polyfunctional and long-lived CD4+ T-cell responses. Here, we show that pGM-CSF co-immunisation improved both magnitude and quality of vaccine-induced T-cell responses, particularly by increasing proliferating CD4+ T-cells that produce simultaneously interferon-γ, tumour necrosis factor-α and interleukin-2. Thus, we believe that the use of pGM-CSF may be helpful for vaccine strategies focused on the activation of anti-HIV CD4+ T-cell immunity. PMID:26602876

Allelic variants of OsSUB1A cause differential expression of transcription factor genes in response to submergence in rice.

PubMed

Sharma, Niharika; Dang, Trang Minh; Singh, Namrata; Ruzicic, Slobodan; Mueller-Roeber, Bernd; Baumann, Ute; Heuer, Sigrid

2018-01-08

Flooding during seasonal monsoons affects millions of hectares of rice-cultivated areas across Asia. Submerged rice plants die within a week due to lack of oxygen, light and excessive elongation growth to escape the water. Submergence tolerance was first reported in an aus-type rice landrace, FR13A, and the ethylene-responsive transcription factor (TF) gene SUB1A-1 was identified as the major tolerance gene. Intolerant rice varieties generally lack the SUB1A gene but some intermediate tolerant varieties, such as IR64, carry the allelic variant SUB1A-2. Differential effects of the two alleles have so far not been addressed. As a first step, we have therefore quantified and compared the expression of nearly 2500 rice TF genes between IR64 and its derived tolerant near isogenic line IR64-Sub1, which carries the SUB1A-1 allele. Gene expression was studied in internodes, where the main difference in expression between the two alleles was previously shown. Nineteen and twenty-six TF genes were identified that responded to submergence in IR64 and IR64-Sub1, respectively. Only one gene was found to be submergence-responsive in both, suggesting different regulatory pathways under submergence in the two genotypes. These differentially expressed genes (DEGs) mainly included MYB, NAC, TIFY and Zn-finger TFs, and most genes were downregulated upon submergence. In IR64, but not in IR64-Sub1, SUB1B and SUB1C, which are also present in the Sub1 locus, were identified as submergence responsive. Four TFs were not submergence responsive but exhibited constitutive, genotype-specific differential expression. Most of the identified submergence responsive DEGs are associated with regulatory hormonal pathways, i.e. gibberellins (GA), abscisic acid (ABA), and jasmonic acid (JA), apart from ethylene. An in-silico promoter analysis of the two genotypes revealed the presence of allele-specific single nucleotide polymorphisms, giving rise to ABRE, DRE/CRT, CARE and Site II cis-elements, which

Neutral endopeptidase activity and airway hyperresponsiveness to neurokinin A in asthmatic subjects in vivo.

PubMed

Cheung, D; Timmers, M C; Zwinderman, A H; den Hartigh, J; Dijkman, J H; Sterk, P J

1993-12-01

In a previous study we have shown that inhibition of the endogenous neuropeptide-degrading enzyme, neutral endopeptidase (NEP), potentiates airway narrowing to neurokinin A (NKA) in normal humans in vivo. In the present study, we tested the hypothesis that hyperresponsiveness to NKA in asthma is caused by a reduction in endogenous NEP activity. To that end, we used the NEP inhibitor, thiorphan, or placebo as inhaled pretreatment to NKA challenge in eight atopic asthmatic men, who were controlled by on-demand usage of beta 2-agonists alone. The dose of thiorphan pretreatment was obtained from pilot experiments in which 0.5 ml of a 2.5-mg/ml concentration appeared to be the maximally effective nebulized dose. Dose-response curves to inhaled NKA (1 to 125 micrograms/ml, 0.5 ml/dose) were recorded on 2 randomized days 1 wk apart, in a cross-over study. To detect any effects of thiorphan on bronchoconstriction per se, we also investigated the effect of thiorphan or placebo on the dose-response curve to inhaled methacholine in a separate set of experiments. The response was measured by FEV1 and by partial expiratory flow-volume curves (V40p). The position of the dose-response curves was expressed as the concentration causing a 20% fall in FEV1 (PC20FEV1) or a 40% fall in V40p (PC40V40p). Baseline FEV1 and V40p were not affected by either pretreatment (p > 0.06). PC20FEV1 and PC40V40p to NKA were significantly lower after thiorphan pretreatment as compared with placebo (mean difference +/- SEM: 2.3 +/- 0.6 and 1.6 +/- 0.5 doubling dose, respectively; p < 0.015).(ABSTRACT TRUNCATED AT 250 WORDS)

Production of soluble Neprilysin by endothelial cells.

PubMed

Kuruppu, Sanjaya; Rajapakse, Niwanthi W; Minond, Dmitriy; Smith, A Ian

2014-04-04

A non-membrane bound form of Neprilysin (NEP) with catalytic activity has the potential to cleave substrates throughout the circulation, thus leading to systemic effects of NEP. We used the endothelial cell line Ea.hy926 to identify the possible role of exosomes and A Disintegrin and Metalloprotease 17 (ADAM-17) in the production of non-membrane bound NEP. Using a bradykinin based quenched fluorescent substrate (40 μM) assay, we determined the activity of recombinant human NEP (rhNEP; 12 ng), and NEP in the media of endothelial cells (10% v/v; after 24 h incubation with cells) to be 9.35±0.70 and 6.54±0.41 μmols of substrate cleaved over 3h, respectively. The presence of NEP in the media was also confirmed by Western blotting. At present there are no commercially available inhibitors specific for ADAM-17. We therefore synthesised two inhibitors TPI2155-14 and TPI2155-17, specific for ADAM-17 with IC50 values of 5.36 and 4.32 μM, respectively. Treatment of cells with TPI2155-14 (15 μM) and TPI2155-17 (4.3 μM) resulted in a significant decrease in NEP activity in media (62.37±1.43 and 38.30±4.70, respectively as a % of control; P<0.0001), implicating a possible role for ADAM-17 in NEP release. However, centrifuging media (100,000g for 1 h at 4 °C) removed all NEP activity from the supernatant indicating the likely role of exosomes in the release of NEP. Our data therefore indicated for the first time that NEP is released from endothelial cells via exosomes, and that this process is dependent on ADAM-17. Copyright © 2014 Elsevier Inc. All rights reserved.

Persisting mild hypothermia suppresses hypoxia-inducible factor-1alpha protein synthesis and hypoxia-inducible factor-1-mediated gene expression.

PubMed

Tanaka, Tomoharu; Wakamatsu, Takuhiko; Daijo, Hiroki; Oda, Seiko; Kai, Shinichi; Adachi, Takehiko; Kizaka-Kondoh, Shinae; Fukuda, Kazuhiko; Hirota, Kiichi

2010-03-01

The transcription factor hypoxia-inducible factor-1 (HIF-1) plays an essential role in regulating gene expression in response to hypoxia-ischemia. Ischemia causes the tissue not only to be hypoxic but also to be hypothermic because of the hypoperfusion under certain circumstances. On the other hand, the induced hypothermia is one of the most common therapeutic modalities to extend tolerance to hypoxia. Although hypoxia elicits a variety of cellular and systemic responses at different organizational levels in the body, little is known about how hypoxia-induced responses are affected by low temperature. We examined the influence of mild hypothermic conditions (28-32 degrees C) on HIF-1 in both in vitro and in vivo settings. In vitro experiments adopting cultured cells elucidated that hypoxia-induced HIF-1 activation was resistant to 4-h exposure to the low temperature. In contrast, exposure to the low temperature as long as 24 h suppressed HIF-1 activation and the subsequent upregulation of HIF-1 target genes such as VEGF or GLUT-1. HIF-1alpha protein stability in the cell was not affected by hypothermic treatment. Furthermore, intracellular ATP content was reduced under 1% O(2) conditions but was not largely affected by hypothermic treatment. The evidence indicates that reduction of oxygen consumption is not largely involved in suppression of HIF-1. In addition, we demonstrated that HIF-1 DNA-binding activity and HIF-1-dependent gene expressions induced under 10% O(2) atmosphere in mouse brain were not influenced by treatment under 3-h hypothermic temperature but were inhibited under 5-h treatment. On the other hand, we indicated that warming ischemic legs of mice for 24 h preserved HIF-1 activity. In this report we describe for the first time that persisting low temperature significantly reduced HIF-1alpha neosynthesis under hypoxic conditions, leading to a decrease in gene expression for adaptation to hypoxia in both in vitro and in vivo settings.

GmSBH1, a homeobox transcription factor gene, relates to growth and development and involves in response to high temperature and humidity stress in soybean.

PubMed

Shu, Yingjie; Tao, Yuan; Wang, Shuang; Huang, Liyan; Yu, Xingwang; Wang, Zhankui; Chen, Ming; Gu, Weihong; Ma, Hao

2015-11-01

GmSBH1 involves in response to high temperature and humidity stress. Homeobox transcription factors are key switches that control plant development processes. Glycine max H1 Sbh1 (GmSBH1) was the first homeobox gene isolated from soybean. In the present study, the full ORF of GmSBH1 was isolated, and the encoded protein was found to be a typical class I KNOX homeobox transcription factor. Subcellular localization and transcriptional activation assays showed that GmSBH1 is a nuclear protein and possesses transcriptional activation activity in the homeodomain. The KNOX1 domain was found to play a clear role in suppressing the transcriptional activation activity of GmSBH1. GmSBH1 showed different expression levels among different soybean tissues and was involved in response to high temperature and humidity (HTH) stress in developing soybean seeds. The overexpression of GmSBH1 in Arabidopsis altered leaf and stoma phenotypes and enhanced seed tolerance to HTH stress. Overall, our results indicated that GmSBH1 is involved in growth, development, and enhances tolerance to pre-harvest seed deterioration caused by HTH stress in soybean.

The integrated endoplasmic reticulum stress response in Leishmania amazonensis macrophage infection: the role of X-box binding protein 1 transcription factor.

PubMed

Dias-Teixeira, Karina Luiza; Calegari-Silva, Teresa Cristina; dos Santos, Guilherme R R M; Vitorino Dos Santos, José; Lima, Carolina; Medina, Jorge Mansur; Aktas, Bertal Huseyin; Lopes, Ulisses G

2016-04-01

Endoplasmic reticulum (ER) stress triggers the integrated ER-stress response (IERSR) that ensures cellular survival of ER stress and represents a primordial form of innate immunity. We investigated the role of IERSR duringLeishmania amazonensisinfection. Treatment of RAW 264.7 infected macrophages with the ER stress-inducing agent thapsigargin (TG; 1 μM) increasedL. amazonensisinfectivity in an IFN1-α receptor (IFNAR)-dependent manner. In Western blot assays, we showed thatL. amazonensisactivates the inositol-requiring enzyme (IRE1)/ X-box binding protein (XBP)-1-splicing arms of the IERSR in host cells. In chromatin immunoprecipitation (ChIP) assays, we showed an increased occupancy of enhancer and promoter sequences for theIfnbgene by XBP1 in infected RAW 264.7 cells. Knocking down XBP1 expression by transducing RAW 264.7 cells with the short hairpin XBP1 lentiviral vector significantly reduced the parasite proliferation associated with impaired translocation of phosphorylated IFN regulatory transcription factor (IRF)-3 to the nucleus and a decrease in IFN1-β expression. Knocking down XBP1 expression also increased NO concentration, as determined by Griess reaction and reduced the expression of antioxidant genes, such as heme oxygenase (HO)-1, that protect parasites from oxidative stress. We conclude thatL. amazonensisactivation of XBP1 plays a critical role in infection by protecting the parasites from oxidative stress and increasing IFN1-β expression.-Dias-Teixeira, K. L., Calegari-Silva, T. C., Dos Santos, G. R. R. M., Vitorino dos Santos, J., Lima, C., Medina, J. M., Aktas, B. H., Lopes, U. G. The integrated endoplasmic reticulum stress response inLeishmania amazonensismacrophage infection: the role of X-box binding protein 1 transcription factor. © FASEB.

Superconducting Hot-Electron Submillimeter-Wave Detector

NASA Technical Reports Server (NTRS)

Karasik, Boris; McGrath, William; Leduc, Henry

2009-01-01

A superconducting hot-electron bolometer has been built and tested as a prototype of high-sensitivity, rapid-response detectors of submillimeter-wavelength radiation. There are diverse potential applications for such detectors, a few examples being submillimeter spectroscopy for scientific research; detection of leaking gases; detection of explosive, chemical, and biological weapons; and medical imaging. This detector is a superconducting-transition- edge device. Like other such devices, it includes a superconducting bridge that has a low heat capacity and is maintained at a critical temperature (T(sub c)) at the lower end of its superconducting-transition temperature range. Incident photons cause transient increases in electron temperature through the superconducting-transition range, thereby yielding measurable increases in electrical resistance. In this case, T(sub c) = 6 K, which is approximately the upper limit of the operating-temperature range of silicon-based bolometers heretofore used routinely in many laboratories. However, whereas the response speed of a typical silicon- based laboratory bolometer is characterized by a frequency of the order of a kilohertz, the response speed of the present device is much higher characterized by a frequency of the order of 100 MHz. For this or any bolometer, a useful figure of merit that one seeks to minimize is (NEP)(tau exp 1/2), where NEP denotes the noise-equivalent power (NEP) and the response time. This figure of merit depends primarily on the heat capacity and, for a given heat capacity, is approximately invariant. As a consequence of this approximate invariance, in designing a device having a given heat capacity to be more sensitive (to have lower NEP), one must accept longer response time (slower response) or, conversely, in designing it to respond faster, one must accept lower sensitivity. Hence, further, in order to increase both the speed of response and the sensitivity, one must make the device very small in

Transforming growth factor β-mediated suppression of antitumor T cells requires FoxP1 transcription factor expression.

PubMed

Stephen, Tom L; Rutkowski, Melanie R; Allegrezza, Michael J; Perales-Puchalt, Alfredo; Tesone, Amelia J; Svoronos, Nikolaos; Nguyen, Jenny M; Sarmin, Fahmida; Borowsky, Mark E; Tchou, Julia; Conejo-Garcia, Jose R

2014-09-18

Tumor-reactive T cells become unresponsive in advanced tumors. Here we have characterized a common mechanism of T cell unresponsiveness in cancer driven by the upregulation of the transcription factor Forkhead box protein P1 (Foxp1), which prevents CD8⁺ T cells from proliferating and upregulating Granzyme-B and interferon-γ in response to tumor antigens. Accordingly, Foxp1-deficient lymphocytes induced rejection of incurable tumors and promoted protection against tumor rechallenge. Mechanistically, Foxp1 interacted with the transcription factors Smad2 and Smad3 in preactivated CD8⁺ T cells in response to microenvironmental transforming growth factor-β (TGF-β), and was essential for its suppressive activity. Therefore, Smad2 and Smad3-mediated c-Myc repression requires Foxp1 expression in T cells. Furthermore, Foxp1 directly mediated TGF-β-induced c-Jun transcriptional repression, which abrogated T cell activity. Our results unveil a fundamental mechanism of T cell unresponsiveness different from anergy or exhaustion, driven by TGF-β signaling on tumor-associated lymphocytes undergoing Foxp1-dependent transcriptional regulation. Copyright © 2014 Elsevier Inc. All rights reserved.

Identification of the functional domain in the transcription factor RTEF-1 that mediates alpha 1-adrenergic signaling in hypertrophied cardiac myocytes.

PubMed

Ueyama, T; Zhu, C; Valenzuela, Y M; Suzow, J G; Stewart, A F

2000-06-09

Cardiac myocytes respond to alpha(1)-adrenergic receptor stimulation by a progressive hypertrophy accompanied by the activation of many fetal genes, including skeletal muscle alpha-actin. The skeletal muscle alpha-actin gene is activated by signaling through an MCAT element, the binding site of the transcription enhancer factor-1 (TEF-1) family of transcription factors. Previously, we showed that overexpression of the TEF-1-related factor (RTEF-1) increased the alpha(1)-adrenergic response of the skeletal muscle alpha-actin promoter, whereas TEF-1 overexpression did not. Here, we identified the functional domains and specific sequences in RTEF-1 that mediate the alpha(1)-adrenergic response. Chimeric TEF-1 and RTEF-1 expression constructs localized the region responsible for the alpha(1)-adrenergic response to the carboxyl-terminal domain of RTEF-1. Site-directed mutagenesis was used to inactivate eight serine residues of RTEF-1, not present in TEF-1, that are putative targets of alpha(1)-adrenergic-dependent kinases. Mutation of a single serine residue, Ser-322, reduced the alpha(1)-adrenergic activation of RTEF-1 by 70% without affecting protein stability, suggesting that phosphorylation at this serine residue accounts for most of the alpha(1)-adrenergic response. Thus, these results demonstrate that RTEF-1 is a direct target of alpha(1)-adrenergic signaling in hypertrophied cardiac myocytes.

Dexamethasone impairs hypoxia-inducible factor-1 function

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wagner, A.E.; Huck, G.; Stiehl, D.P.

2008-07-25

Hypoxia-inducible factor-1 (HIF-1) is a heterodimeric transcription-factor composed of {alpha}- and {beta}-subunits. HIF-1 is not only necessary for the cellular adaptation to hypoxia, but it is also involved in inflammatory processes and wound healing. Glucocorticoids (GC) are therapeutically used to suppress inflammatory responses. Herein, we investigated whether GC modulate HIF-1 function using GC receptor (GR) possessing (HepG2) and GR deficient (Hep3B) human hepatoma cell cultures as model systems. Dexamethasone (DEX) treatment increased HIF-1{alpha} levels in the cytosol of HepG2 cells, while nuclear HIF-1{alpha} levels and HIF-1 DNA-binding was reduced. In addition, DEX dose-dependently lowered the hypoxia-induced luciferase activity in amore » reporter gene system. DEX suppressed the hypoxic stimulation of the expression of the HIF-1 target gene VEGF (vascular endothelial growth factor) in HepG2 cultures. DEX did not reduce hypoxically induced luciferase activity in HRB5 cells, a Hep3B derivative lacking GR. Transient expression of the GR in HRB5 cells restored the susceptibility to DEX. Our study discloses the inhibitory action of GC on HIF-1 dependent gene expression, which may be important with respect to the impaired wound healing in DEX-treated patients.« less

Climate controls over ecosystem metabolism: insights from a fifteen-year inductive artificial neural network synthesis for a subalpine forest.

PubMed

Albert, Loren P; Keenan, Trevor F; Burns, Sean P; Huxman, Travis E; Monson, Russell K

2017-05-01

Eddy covariance (EC) datasets have provided insight into climate determinants of net ecosystem productivity (NEP) and evapotranspiration (ET) in natural ecosystems for decades, but most EC studies were published in serial fashion such that one study's result became the following study's hypothesis. This approach reflects the hypothetico-deductive process by focusing on previously derived hypotheses. A synthesis of this type of sequential inference reiterates subjective biases and may amplify past assumptions about the role, and relative importance, of controls over ecosystem metabolism. Long-term EC datasets facilitate an alternative approach to synthesis: the use of inductive data-based analyses to re-examine past deductive studies of the same ecosystem. Here we examined the seasonal climate determinants of NEP and ET by analyzing a 15-year EC time-series from a subalpine forest using an ensemble of Artificial Neural Networks (ANNs) at the half-day (daytime/nighttime) time-step. We extracted relative rankings of climate drivers and driver-response relationships directly from the dataset with minimal a priori assumptions. The ANN analysis revealed temperature variables as primary climate drivers of NEP and daytime ET, when all seasons are considered, consistent with the assembly of past studies. New relations uncovered by the ANN approach include the role of soil moisture in driving daytime NEP during the snowmelt period, the nonlinear response of NEP to temperature across seasons, and the low relevance of summer rainfall for NEP or ET at the same daytime/nighttime time step. These new results offer a more complete perspective of climate-ecosystem interactions at this site than traditional deductive analyses alone.

Emotional Responses to Suicidal Patients: Factor Structure, Construct, and Predictive Validity of the Therapist Response Questionnaire-Suicide Form.

PubMed

Barzilay, Shira; Yaseen, Zimri S; Hawes, Mariah; Gorman, Bernard; Altman, Rachel; Foster, Adriana; Apter, Alan; Rosenfield, Paul; Galynker, Igor

2018-01-01

Mental health professionals have a pivotal role in suicide prevention. However, they also often have intense emotional responses, or countertransference, during encounters with suicidal patients. Previous studies of the Therapist Response Questionnaire-Suicide Form (TRQ-SF), a brief novel measure aimed at probing a distinct set of suicide-related emotional responses to patients found it to be predictive of near-term suicidal behavior among high suicide-risk inpatients. The purpose of this study was to validate the TRQ-SF in a general outpatient clinic setting. Adult psychiatric outpatients ( N  = 346) and their treating mental health professionals ( N  = 48) completed self-report assessments following their first clinic meeting. Clinician measures included the TRQ-SF, general emotional states and traits, therapeutic alliance, and assessment of patient suicide risk. Patient suicidal outcomes and symptom severity were assessed at intake and one-month follow-up. Following confirmatory factor analysis of the TRQ-SF, factor scores were examined for relationships with clinician and patient measures and suicidal outcomes. Factor analysis of the TRQ-SF confirmed three dimensions: (1) affiliation, (2) distress, and (3) hope. The three factors also loaded onto a single general factor of negative emotional response toward the patient that demonstrated good internal reliability. The TRQ-SF scores were associated with measures of clinician state anger and anxiety and therapeutic alliance, independently of clinician personality traits after controlling for the state- and patient-specific measures. The total score and three subscales were associated in both concurrent and predictive ways with patient suicidal outcomes, depression severity, and clinicians' judgment of patient suicide risk, but not with global symptom severity, thus indicating specifically suicide-related responses. The TRQ-SF is a brief and reliable measure with a 3-factor structure. It demonstrates

Cytokine Response of Cultured Skeletal Muscle Cells Stimulated with Proinflammatory Factors Depends on Differentiation Stage

PubMed Central

Podbregar, Matej; Lainscak, Mitja; Prelovsek, Oja; Mars, Tomaz

2013-01-01

Myoblast proliferation and myotube formation are critical early events in skeletal muscle regeneration. The attending inflammation and cytokine signaling are involved in regulation of skeletal muscle cell proliferation and differentiation. Secretion of muscle-derived cytokines upon exposure to inflammatory factors may depend on the differentiation stage of regenerating muscle cells. Cultured human myoblasts and myotubes were exposed to 24-hour treatment with tumor necrosis factor (TNF)-α or lipopolysaccharide (LPS). Secretion of interleukin 6 (IL-6), a major muscle-derived cytokine, and interleukin 1 (IL-1), an important regulator of inflammatory response, was measured 24 hours after termination of TNF-α or LPS treatment. Myoblasts pretreated with TNF-α or LPS displayed robustly increased IL-6 secretion during the 24-hour period after removal of treatments, while IL-1 secretion remained unaltered. IL-6 secretion was also increased in myotubes, but the response was less pronounced compared with myoblasts. In contrast to myoblasts, IL-1 secretion was markedly stimulated in LPS-pretreated myotubes. We demonstrate that preceding exposure to inflammatory factors stimulates a prolonged upregulation of muscle-derived IL-6 and/or IL-1 in cultured skeletal muscle cells. Our findings also indicate that cytokine response to inflammatory factors in regenerating skeletal muscle partially depends on the differentiation stage of myogenic cells. PMID:23509435

End-boundary sheath potential, electron and ion energy distribution in the low-pressure non-ambipolar electron plasma

NASA Astrophysics Data System (ADS)

Chen, Lee; Chen, Zhiying; Funk, Merritt

2013-12-01

The end-boundary floating-surface sheath potential, electron and ion energy distribution functions (EEDf, IEDf) in the low-pressure non-ambipolar electron plasma (NEP) are investigated. The NEP is heated by an electron beam extracted from an inductively coupled electron-source plasma (ICP) through a dielectric injector by an accelerator located inside the NEP. This plasma's EEDf has a Maxwellian bulk followed by a broad energy continuum connecting to the most energetic group with energies around the beam energy. The NEP pressure is 1-3 mTorr of N2 and the ICP pressure is 5-15 mTorr of Ar. The accelerator is biased positively from 80 to 600 V and the ICP power range is 200-300 W. The NEP EEDf and IEDf are determined using a retarding field energy analyser. The EEDf and IEDf are measured at various NEP pressures, ICP pressures and powers as a function of accelerator voltage. The accelerator current and sheath potential are also measured. The IEDf reveals mono-energetic ions with adjustable energy and it is proportionally controlled by the sheath potential. The NEP end-boundary floating surface is bombarded by a mono-energetic, space-charge-neutral plasma beam. When the injected energetic electron beam is adequately damped by the NEP, the sheath potential is linearly controlled at almost a 1 : 1 ratio by the accelerator voltage. If the NEP parameters cannot damp the electron beam sufficiently, leaving an excess amount of electron-beam power deposited on the floating surface, the sheath potential will collapse and become unresponsive to the accelerator voltage.