Measurements of Branching Ratios And Search for CP Violation in the Modes B0 to Rho Pi, Rho K (in French)

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

Laplace, Sandrine; /Paris U., VI-VII

2006-09-18

The BABAR experiment, at the PEP-II collider at SLAC, has been studying since 1999 CP violation in the B meson system. After the precise measurement of sin2{beta}, one is now concentrating on measuring the angles {alpha} and {gamma} of the unitarity triangle. The work presented in this thesis concerns the measurement of the angle {alpha} in the B{sup 0} {yields} {rho}{pi} mode.

The Scalar Resonances a0/f0(980) at COSY

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

Buescher, M.

2006-02-11

Fundamental properties of the scalar resonances a0/f0(980), like their masses, widths and couplings to KK-bar, are poorly known. In particular, precise knowledge of the latter quantity would be of great importance since it can be related to the KK-bar content of these resonances.An experimental program is under way at COSY-Juelich aiming at the extraction of the isospin violating a0/f0 mixing amplitude {lambda} which is in leading order proportional to the product of the coupling constants of the a0 and f0 to kaons. a0/f0 production is studied in pp, pn and dd interactions, both for the KK-bar and the {pi}{eta}/{pi}{pi} decays,more » using the ANKE and WASA spectrometers. The latter will be available for measurements at COSY in 2007.As a first step, isovector KK-bar production has been measured in the reaction pp {yields} dK+K-bar0. The data reveal dominance of the a{sub 0}{sup +} channel, thus demonstrating the feasibility of scalar meson studies at COSY. Analyses of KK-bar- and K-bard-FSI effects yield the corresponding scattering lengths, a(KK-bar)I=1 = -(0.02 {+-} 0.03) - i(0.61 {+-} 0.05) fm and vertical bar Re a(K-bard) vertical bar {<=}1.3 fm, Im a(K-bard){<=}1.3 fm.« less

Rho'ing in and out of cells: viral interactions with Rho GTPase signaling.

PubMed

Van den Broeke, Céline; Jacob, Thary; Favoreel, Herman W

2014-01-01

Rho GTPases are key regulators of actin and microtubule dynamics and organization. Increasing evidence shows that many viruses have evolved diverse interactions with Rho GTPase signaling and manipulate them for their own benefit. In this review, we discuss how Rho GTPase signaling interferes with many steps in the viral replication cycle, especially entry, replication, and spread. Seen the diversity between viruses, it is not surprising that there is considerable variability in viral interactions with Rho GTPase signaling. However, several largely common effects on Rho GTPases and actin architecture and microtubule dynamics have been reported. For some of these processes, the molecular signaling and biological consequences are well documented while for others we just begin to understand them. A better knowledge and identification of common threads in the different viral interactions with Rho GTPase signaling and their ultimate consequences for virus and host may pave the way toward the development of new antiviral drugs that may target different viruses.

Measurement of the Branching Fraction, Polarization, and CP Asymmetry for B{sup 0}{yields}{rho}{sup +}{rho}{sup -} Decays, and Determination of the Cabibbo-Kobayashi-Maskawa Phase {phi}{sub 2}

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

Somov, A.; Schwartz, A.J.; Bahinipati, S.

2006-05-05

We have measured the branching fraction B, longitudinal polarization fraction f{sub L}, and CP asymmetry coefficients A and S for B{sup 0}{yields}{rho}{sup +}{rho}{sup -} decays with the Belle detector at the KEKB e{sup +}e{sup -} collider using 253 fb{sup -1} of data. We obtain B=[22.8{+-}3.8(stat){sub -2.6}{sup +2.3}(syst)]x10{sup -6}, f{sub L}=0.941{sub -0.040}{sup +0.034}(stat){+-}0.030(syst), A=0.00{+-}0.30(stat){+-}0.09(syst), and S=0.08{+-}0.41(stat){+-}0.09(syst). These values are used to constrain the Cabibbo-Kobayashi-Maskawa phase {phi}{sub 2}; the solution consistent with the standard model is {phi}{sub 2}=(88{+-}17) deg. or 59 deg. <{phi}{sub 2}<115 deg. at 90% C.L.

Rho A and the Rho kinase pathway regulate fibroblast contraction: Enhanced contraction in constitutively active Rho A fibroblast cells

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

Nobe, Koji, E-mail: kojinobe@pharm.showa-u.ac.jp; Nobe, Hiromi; Department of Physical Therapy, Bunkyo-Gakuin University

Research highlights: {yields} Mechanisms of fibroblast cell contraction in collagen matrix. {yields} Assessed an isometric force development using 3D-reconstituted-fibroblast fiber. {yields} Constitutively active Rho A induced the over-contraction of fibroblast cells. {yields} Rho A and Rho kinase pathway has a central role in fibroblast cell contraction. -- Abstract: Fibroblast cells play a central role in the proliferation phase of wound healing processes, contributing to force development. The intracellular signaling pathways regulating this non-muscle contraction are only partially understood. To study the relations between Rho A and contractile responses, constitutively active Rho A (CA-Rho A) fibroblast cells were reconstituted into fibersmore » and the effects of calf serum (CS) on isometric force were studied. CS-induced force in CA-Rho A fibroblast fibers was twice as large as that in wild type (NIH 3T3) fibroblast fibers. During this response, the translocation of Rho A from the cytosol to the membrane was detected by Rho A activity assays and Western blot analysis. Pre-treatment with a Rho specific inhibitor (C3-exoenzyme) suppressed translocation as well as contraction. These results indicate that Rho A activation is essential for fibroblast contraction. The Rho kinase inhibitor ( (Y27632)) inhibited both NIH 3T3 and CA-Rho A fibroblast fiber contractions. Activation of Rho A is thus directly coupled with Rho kinase activity. We conclude that the translocation of Rho A from the cytosol to the membrane and the Rho kinase pathway can regulate wound healing processes mediated by fibroblast contraction.« less

Breath-hold black-blood T1rho mapping improves liver T1rho quantification in healthy volunteers.

PubMed

Wáng, Yì Xiáng J; Deng, Min; Lo, Gladys G; Liang, Dong; Yuan, Jing; Chen, Weitian

2018-03-01

Background Recent researches suggest that T1rho may be a non-invasive and quantitative technique for detecting and grading liver fibrosis. Purpose To compare a multi-breath-hold bright-blood fast gradient echo (GRE) imaging and a single breath-hold single-shot fast spin echo (FSE) imaging with black-blood effect for liver parenchyma T1rho measurement and to study liver physiological T1rho value in healthy volunteers. Material and Methods The institutional Ethics Committee approved this study. 28 healthy participants (18 men, 10 women; age = 29.6 ± 5.1 years) underwent GRE liver T1rho imaging, and 20 healthy participants (10 men, 10 women; age = 36.9 ± 10.3 years) underwent novel black-blood FSE liver T1rho imaging, both at 3T with spin-lock frequency of 500 Hz. The FSE technique allows simultaneous acquisition of four spin lock times (TSLs; 1 ms, 10 ms, 30 ms, 50msec) in 10 s. Results For FSE technique the intra-scan repeatability intraclass correlation coefficient (ICC) was 0.98; while the inter-scan reproducibility ICC was 0.82 which is better than GRE technique's 0.76. Liver T1rho value in women tended to have a higher value than T1rho values in men (FSE: 42.28 ± 4.06 ms for women and 39.13 ± 2.12 ms for men; GRE: 44.44 ± 1.62 ms for women and 42.36 ± 2.00 ms for men) and FSE technique showed liver T1rho value decreased slightly as age increased. Conclusion Single breath-hold black-blood FSE sequence has better scan-rescan reproducibility than multi-breath-hold bright-blood GRE sequence. Gender and age dependence of liver T1rho in healthy participants is observed, with young women tending to have a higher T1rho measurement.

RhoA/Rho-kinase triggers epithelial-mesenchymal transition in mesothelial cells and contributes to the pathogenesis of dialysis-related peritoneal fibrosis

PubMed Central

Wang, Qinglian; Yang, Xiaowei; Xu, Ying; Shen, Zhenwei; Cheng, Hongxia; Cheng, Fajuan; Liu, Xiang; Wang, Rong

2018-01-01

Peritoneal fibrosis (PF) with associated peritoneal dysfunction is almost invariably observed in long-term peritoneal dialysis (PD) patients. Advanced glycation end products (AGEs) are pro-oxidant compounds produced in excess during the metabolism of glucose and are present in high levels in standard PD solutions. The GTPase RhoA has been implicated in PF, but its specific role remains poorly understood. Here, we studied the effects of RhoA/Rho-kinase signaling in AGEs-induced epithelial-mesenchymal transition (EMT) in human peritoneal mesothelial cells (HPMCs), and evaluated morphological and molecular changes in a rat model of PD-related PF. Activation of RhoA/Rho-kinase and activating protein-1 (AP-1) was assessed in HPMCs using pull-down and electrophoretic mobility shift assays, respectively, while expression of transforming growth factor-β, fibronectin, α-smooth muscle actin, vimentin, N-cadherin, and E-cadherin expression was assessed using immunohistochemistry and western blot. AGEs exposure activated Rho/Rho-kinase in HPMCs and upregulated EMT-related genes via AP-1. These changes were prevented by the Rho-kinase inhibitors fasudil and Y-27632, and by the AP-1 inhibitor curcumin. Importantly, fasudil normalized histopathological and molecular alterations and preserved peritoneal function in rats. These data support the therapeutic potential of Rho-kinase inhibitors in PD-related PF. PMID:29581852

Different experimental results for the influence of immersion angle on the resonant frequency of a quartz crystal microbalance in a liquid phase: with a comment.

PubMed

Shen, Dazhong; Kang, Qi; Li, Xiaoyu; Cai, Hongmei; Wang, Yuandong

2007-06-19

This paper presents different experimental results of the influence of an immersion angle (theta, the angle between the surface of a quartz crystal resonator and the horizon) on the resonant frequency of a quartz crystal microbalance (QCM) sensor exposed one side of its sensing surfaces to liquid. The experimental results show that the immersion angle is an added factor that may influence the frequency of the QCM sensor. This type of influence is caused by variation of the reflection conditions of the longitudinal wave between the QCM sensor and the walls of the detection cell. The frequency shifts, measured by varying theta, are related to the QCM sensor used. When a QCM sensor with a weak longitudinal wave is used, its resonant frequency is nearly independent of theta. But, if a QCM sensor with a strong longitudinal wave is employed, the immersion angle is a potential error source for the measurements performed on the QCM sensor. When the reflection conditions of the longitudinal wave are reduced, the influence of theta on the resonant frequency of the QCM sensor is negligible. The slope of the plot of frequency shifts (deltaF) versus (rho eta)(1/2), the square root of the product of solution density (rho) and viscosity (eta), may be influenced by theta in a single experiment for the QCM sensor with a strong longitudinal wave in low viscous liquids, which can however, be effectively weakened by using the averaged values of reduplicated experiments. In solutions with a large (rho eta)(1/2) region (0-55 wt% sucrose solution as an example, with rho value from 1.00 to 1.26 g cm(-3) and eta value from 0.01 to 0.22 g cm(-1) s(-1), respectively), the slope of the plot of deltaF versus (rho eta)(1/2) is independent of theta even for the QCM sensor with a strong longitudinal wave in a single experiment. The influence of theta on the resonant frequency of the QCM sensor should be taken into consideration in its applications in liquid phase.

Involvement of Rho-kinase in cold ischemia-reperfusion injury after liver transplantation in rats.

PubMed

Shiotani, Satoko; Shimada, Mitsuo; Suehiro, Taketoshi; Soejima, Yuji; Yosizumi, Tomoharu; Shimokawa, Hiroaki; Maehara, Yoshihiko

2004-08-15

Reperfusion of ischemic tissues is known to cause the generation of reactive oxygen species (ROS) with resultant tissue damage. However, the sources of ROS in reperfused tissues are not fully characterized. We hypothesized that the small GTPase Rho and its target effector Rho-kinase/ROK/ROCK are involved in the oxidative burst in reperfused tissue with resultant reperfusion injury. In an in vivo rat model of liver transplantation using cold ischemia for 12 hr followed by reperfusion, a specific Rho-kinase inhibitor, fasudil (30 mg/kg), was administered orally 1 hr before the transplantation. Fasudil suppressed the ischemia-reperfusion (I/R)-induced generation of ROS after reperfusion (P<0.01) and also suppressed the release of inflammatory cytokines (tumor necrosis factor-alpha, interleukin-1beta) 3 hr after reperfusion, resulting in a significant reduction of I/R-induced hepatocellular injury (P<0.05), necrosis, apoptosis (P<0.01), and neutrophil infiltration (P<0.0001) 12 hr after reperfusion. All animals receiving a graft without fasudil died within 3 days, whereas 40% of those receiving fasudil survived (P<0.001). The present study demonstrates that Rho-kinase-mediated production of ROS and inflammatory cytokines are substantially involved in the pathogenesis of hepatocellular necrosis and apoptosis induced by cold I/R in vivo and that Rho-kinase may be regarded as a novel therapeutic target for the disorder.

Three-dimensional T1rho-weighted MRI at 1.5 Tesla.

PubMed

Borthakur, Arijitt; Wheaton, Andrew; Charagundla, Sridhar R; Shapiro, Erik M; Regatte, Ravinder R; Akella, Sarma V S; Kneeland, J Bruce; Reddy, Ravinder

2003-06-01

To design and implement a magnetic resonance imaging (MRI) pulse sequence capable of performing three-dimensional T(1rho)-weighted MRI on a 1.5-T clinical scanner, and determine the optimal sequence parameters, both theoretically and experimentally, so that the energy deposition by the radiofrequency pulses in the sequence, measured as the specific absorption rate (SAR), does not exceed safety guidelines for imaging human subjects. A three-pulse cluster was pre-encoded to a three-dimensional gradient-echo imaging sequence to create a three-dimensional, T(1rho)-weighted MRI pulse sequence. Imaging experiments were performed on a GE clinical scanner with a custom-built knee-coil. We validated the performance of this sequence by imaging articular cartilage of a bovine patella and comparing T(1rho) values measured by this sequence to those obtained with a previously tested two-dimensional imaging sequence. Using a previously developed model for SAR calculation, the imaging parameters were adjusted such that the energy deposition by the radiofrequency pulses in the sequence did not exceed safety guidelines for imaging human subjects. The actual temperature increase due to the sequence was measured in a phantom by a MRI-based temperature mapping technique. Following these experiments, the performance of this sequence was demonstrated in vivo by obtaining T(1rho)-weighted images of the knee joint of a healthy individual. Calculated T(1rho) of articular cartilage in the specimen was similar for both and three-dimensional and two-dimensional methods (84 +/- 2 msec and 80 +/- 3 msec, respectively). The temperature increase in the phantom resulting from the sequence was 0.015 degrees C, which is well below the established safety guidelines. Images of the human knee joint in vivo demonstrate a clear delineation of cartilage from surrounding tissues. We developed and implemented a three-dimensional T(1rho)-weighted pulse sequence on a 1.5-T clinical scanner. Copyright 2003

Measurement of meson resonance production in $$\\pi ^- + C$$ interactions at SPS energies: The NA61/SHINE Collaboration

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

Aduszkiewicz, A.; Ali, Y.; Andronov, E. V.

Here, we present measurements ofmore » $$\\rho^0$$, $$\\omega$$ and K$$^{*0}$$ spectra in $$\\pi^{-} + $$C production interactions at 158 GeV/c and $$\\rho^0$$ spectra at 350 GeV/c using the NA61/SHINE spectrometer at the CERN SPS. Spectra are presented as a function of the Feynman's variable $$x_\\text{F}$$ in the range $$0 < x_\\text{F} < 1$$ and $$0 < x_\\text{F} < 0.5$$ for 158 GeV/c and 350 GeV/c respectively. Furthermore, we show comparisons with previous measurements and predictions of several hadronic interaction models. Our measurements are essential for a better understanding of hadronic shower development and for improving the modeling of cosmic ray air showers.« less

Measurement of meson resonance production in $$\\pi ^- + C$$ interactions at SPS energies: The NA61/SHINE Collaboration

DOE PAGES

Aduszkiewicz, A.; Ali, Y.; Andronov, E. V.; ...

2017-09-20

Here, we present measurements ofmore » $$\\rho^0$$, $$\\omega$$ and K$$^{*0}$$ spectra in $$\\pi^{-} + $$C production interactions at 158 GeV/c and $$\\rho^0$$ spectra at 350 GeV/c using the NA61/SHINE spectrometer at the CERN SPS. Spectra are presented as a function of the Feynman's variable $$x_\\text{F}$$ in the range $$0 < x_\\text{F} < 1$$ and $$0 < x_\\text{F} < 0.5$$ for 158 GeV/c and 350 GeV/c respectively. Furthermore, we show comparisons with previous measurements and predictions of several hadronic interaction models. Our measurements are essential for a better understanding of hadronic shower development and for improving the modeling of cosmic ray air showers.« less

Differential binding of RhoA, RhoB, and RhoC to protein kinase C-related kinase (PRK) isoforms PRK1, PRK2, and PRK3: PRKs have the highest affinity for RhoB.

PubMed

Hutchinson, Catherine L; Lowe, Peter N; McLaughlin, Stephen H; Mott, Helen R; Owen, Darerca

2013-11-12

Protein kinase C-related kinases (PRKs) are members of the protein kinase C superfamily of serine-threonine kinases and can be activated by binding to members of the Rho family of GTPases via a Rho-binding motif known as an HR1 domain. Three tandem HR1 domains reside at the N-terminus of the PRKs. We have assessed the ability of the HR1a and HR1b domains from the three PRK isoforms (PRK1, PRK2, and PRK3) to interact with the three Rho isoforms (RhoA, RhoB, and RhoC). The affinities of RhoA and RhoC for a construct encompassing both PRK1 HR1 domains were similar to those for the HR1a domain alone, suggesting that these interactions are mediated solely by the HR1a domain. The affinities of RhoB for both the PRK1 HR1a domain and the HR1ab didomain were higher than those of RhoA or RhoC. RhoB also bound more tightly to the didomain than to the HR1a domain alone, implicating the HR1b domain in the interaction. As compared with PRK1 HR1 domains, PRK2 and PRK3 domains bind less well to all Rho isoforms. Uniquely, however, the PRK3 domains display a specificity for RhoB that requires both the C-terminus of RhoB and the PRK3 HR1b domain. The thermal stability of the HR1a and HR1b domains was also investigated. The PRK2 HR1a domain was found to be the most thermally stable, while PRK2 HR1b, PRK3 HR1a, and PRK3 HR1b domains all exhibited lower melting temperatures, similar to that of the PRK1 HR1a domain. The lower thermal stability of the PRK2 and PRK3 HR1b domains may impart greater flexibility, driving their ability to interact with Rho isoforms.

Pathophysiological effects of RhoA and Rho-associated kinase on cardiovascular system.

PubMed

Cai, Anping; Li, Liwen; Zhou, Yingling

2016-01-01

In past decades, growing evidence from basic and clinical researches reveal that small guanosine triphosphate binding protein ras homolog gene family, member A (RhoA) and its main effector Rho-associated kinase (ROCK) play central and complex roles in cardiovascular systems, and increasing RhoA and ROCK activity is associated with a broad range of cardiovascular diseases such as congestive heart failure, atherosclerosis, and hypertension. Favorable outcomes have been observed with ROCK inhibitors treatment. In this review, we briefly summarize the pathophysiological roles of RhoA/ROCK signaling pathway on cardiovascular system, displaying the potential benefits in the cardiovascular system with controlling RhoA/ROCK signaling pathway.

Role of the strange quark in the rho(770) meson

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

Molina Peralta, Raquel; Guo, Dehua; Hu, B.

2017-03-01

Recently, the GWU lattice group has evaluated high-precision phase-shift data formore » $$\\pi\\pi$$ scattering in the $I = 1$, $J = 1$ channel. Unitary Chiral Perturbation Theory describes these data well around the resonance region and for different pion masses. Moreover, it allows to extrapolate to the physical point and estimate the effect of the missing $$K\\bar{K}$$ channel in the two-flavor lattice calculation. The absence of the strange quark in the lattice data leads to a lower $$\\rho$$ mass, and the analysis with U$$\\chi$$PT shows that the $$K \\bar{K}$$ channel indeed pushes the $$\\pi\\pi$$-scattering phase shift upward, having a surprisingly large effect on the $$\\rho$$-mass. The inelasticity is shown to be compatible with the experimental data. The analysis is then extended to all available two-flavor lattice simulations and similar mass shifts are observed. Chiral extrapolations of $$N_f = 2 + 1$$ lattice simulations for the $$\\rho(770)$$ are also reported.« less

Rho GTPases and their downstream effectors in megakaryocyte biology.

PubMed

Pleines, Irina; Cherpokova, Deya; Bender, Markus

2018-06-18

Megakaryocytes differentiate from hematopoietic stem cells in the bone marrow. The transition of megakaryocytes to platelets is a complex process. Thereby, megakaryocytes extend proplatelets into sinusoidal blood vessels, where the proplatelets undergo fission to release platelets. Defects in platelet production can lead to a low platelet count (thrombocytopenia) with increased bleeding risk. Rho GTPases comprise a family of small signaling G proteins that have been shown to be master regulators of the cytoskeleton controlling many aspects of intracellular processes. The generation of Pf4-Cre transgenic mice was a major breakthrough that enabled studies in megakaryocyte-/platelet-specific knockout mouse lines and provided new insights into the central regulatory role of Rho GTPases in megakaryocyte maturation and platelet production. In this review, we will summarize major findings on the role of Rho GTPases in megakaryocyte biology with a focus on mouse lines in which knockout strategies have been applied to study the function of the best-characterized members Rac1, Cdc42 and RhoA and their downstream effector proteins.

Targeting RhoA/Rho kinase and p21-activated kinase signaling to prevent cancer development and progression.

PubMed

Chang, Yu-Wen E; Bean, Ronald R; Jakobi, Rolf

2009-06-01

Elevated RhoA/Rho kinase and p21-activated kinase signaling have been shown to promote cancer development and metastasis and have drawn much attention as potential targets of anti-cancer therapy. Elevated RhoA and Rho kinase activity promote cancer cell invasion and eventually lead to metastasis by disrupting E-cadherin-mediated adherens junctions and degradation of the extracellular matrix. Elevated p21-activated kinase activity promotes invasion by stimulating cell motility but also promotes cancer cell survival and growth. In this review we describe normal functions of RhoA/Rho kinase and p21-activated kinase signaling, mechanisms that lead to constitutive activation of RhoA/Rho kinase and p21-activated kinase pathways, and processes by which constitutive RhoA/Rho kinase and p21-activated kinase activity promote cancer development and progression to more aggressive and metastatic phenotypes. In addition, we summarize relevant patents on RhoA/Rho kinase and p21-activated kinase as targets of anti-cancer therapy and discuss the clinical potential of different approaches to modulate RhoA/Rho kinase and p21-activated kinase signaling.

Substrate rigidity regulates Ca2+ oscillation via RhoA pathway in stem cells

PubMed Central

Kim, Tae-Jin; Seong, Jihye; Ouyang, Mingxing; Sun, Jie; Lu, Shaoying; Hong, Jun Pyu; Wang, Ning; Wang, Yingxiao

2008-01-01

Substrate rigidity plays crucial roles in regulating cellular functions, such as cell spreading, traction forces, and stem cell differentiation. However, it is not clear how substrate rigidity influences early cell signaling events such as calcium in living cells. Using highly-sensitive Ca2+ biosensors based on fluorescence resonance energy transfer (FRET), we investigated the molecular mechanism by which substrate rigidity affects calcium signaling in human mesenchymal stem cells (HMSCs). Spontaneous Ca2+ oscillations were observed inside the cytoplasm and the endoplasmic reticulum (ER) using the FRET biosensors targeted at subcellular locations in cells plated on rigid dishes. Lowering the substrate stiffness to 1 kPa significantly inhibited both the magnitudes and frequencies of the cytoplasmic Ca2+ oscillation in comparison to stiffer or rigid substrate. This Ca2+ oscillation was shown to be dependent on ROCK, a downstream effector molecule of RhoA, but independent of actin filaments, microtubules, myosin light chain kinase, or myosin activity. Lysophosphatidic acid, which activates RhoA, also inhibited the frequency of the Ca2+ oscillation. Consistently, either a constitutive active mutant of RhoA (RhoA-V14) or a dominant negative mutant of RhoA (RhoA-N19) inhibited the Ca2+ oscillation. Further experiments revealed that HMSCs cultured on gels with low elastic moduli displayed low RhoA activities. Therefore, our results demonstrate that RhoA and its downstream molecule ROCK may mediate the substrate rigidity-regulated Ca2+ oscillation, which determines the physiological functions of HMSCs. PMID:18844232

Measurements of Hadron Resonance Production with ALICE

NASA Astrophysics Data System (ADS)

Fragiacomo, Enrico

Short-lived resonances have long been recognized as good probes to investigate the late-stage evolution of ultra-relativistic heavy-ion collisions. More recently, resonances with different masses and quark composition have provided valuable contributions to the understanding of strangeness production, in particular for the observed multiplicity-dependent enhancement in small systems. In this light, a comprehensive review is presented of the most recent ALICE results on ρ(770)0, K∗(892)0, ϕ(1020), Σ(1385)±, Λ(1520) and Ξ(1530)0 production in pp, p-Pb and Pb-Pb collisions at various collision energies at the LHC, including results from the latest Pb-Pb run at sNN = 5.02 TeV.

Direct multiplex imaging and optogenetics of Rho GTPases enabled by near-infrared FRET.

PubMed

Shcherbakova, Daria M; Cox Cammer, Natasha; Huisman, Tsipora M; Verkhusha, Vladislav V; Hodgson, Louis

2018-06-01

Direct visualization and light control of several cellular processes is a challenge, owing to the spectral overlap of available genetically encoded probes. Here we report the most red-shifted monomeric near-infrared (NIR) fluorescent protein, miRFP720, and the fully NIR Förster resonance energy transfer (FRET) pair miRFP670-miRFP720, which together enabled design of biosensors compatible with CFP-YFP imaging and blue-green optogenetic tools. We developed a NIR biosensor for Rac1 GTPase and demonstrated its use in multiplexed imaging and light control of Rho GTPase signaling pathways. Specifically, we combined the Rac1 biosensor with CFP-YFP FRET biosensors for RhoA and for Rac1-GDI binding, and concurrently used the LOV-TRAP tool for upstream Rac1 activation. We directly observed and quantified antagonism between RhoA and Rac1 dependent on the RhoA-downstream effector ROCK; showed that Rac1 activity and GDI binding closely depend on the spatiotemporal coordination between these two molecules; and simultaneously observed Rac1 activity during optogenetic manipulation of Rac1.

The atypical Rho GTPase RhoD is a regulator of actin cytoskeleton dynamics and directed cell migration

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

Blom, Magdalena; Reis, Katarina; Heldin, Johan

RhoD belongs to the Rho GTPases, a protein family responsible for the regulation and organization of the actin cytoskeleton, and, consequently, many cellular processes like cell migration, cell division and vesicle trafficking. Here, we demonstrate that the actin cytoskeleton is dynamically regulated by increased or decreased protein levels of RhoD. Ectopic expression of RhoD has previously been shown to give an intertwined weave of actin filaments. We show that this RhoD-dependent effect is detected in several cell types and results in a less dynamic actin filament system. In contrast, RhoD depletion leads to increased actin filament-containing structures, such as corticalmore » actin, stress fibers and edge ruffles. Moreover, vital cellular functions such as cell migration and proliferation are defective when RhoD is silenced. Taken together, we present data suggesting that RhoD is an important component in the control of actin dynamics and directed cell migration. - Highlights: • Increased RhoD expression leads to loss of actin structures, e.g. stress fibers and gives rise to decreased actin dynamics. • RhoD knockdown induces various actin-containing structures such as edge ruffles, stress fibers and cortical actin, in a cell-type specific manner. • RhoD induces specific actin rearrangements depending on its subcellular localization. • RhoD knockdown has effects on cellular processes, such as directed cell migration and proliferation.« less

Relation of RhoA in Peripheral Blood Mononuclear Cells With Severity of Aneurysmal Subarachnoid Hemorrhage and Vasospasm.

PubMed

González-Montelongo, María Del Carmen; Egea-Guerrero, Juan José; Murillo-Cabezas, Francisco; González-Montelongo, Rafaela; Ruiz de Azúa-López, Zaida; Rodríguez-Rodríguez, Ana; Vilches-Arenas, Angel; Castellano, Antonio; Ureña, Juan

2018-06-01

Rho-kinase, an effector of RhoA, is associated with various cardiovascular diseases in circulating blood cells. However, the role of RhoA/Rho-kinase in peripheral blood mononuclear cells from patients with spontaneous aneurysmal subarachnoid hemorrhage (aSAH) has not yet been studied in relation to the severity of this disease. Therefore, we analyzed the expression and activity of RhoA as a possible biomarker in aSAH. Twenty-four patients with aSAH and 15 healthy subjects were examined. Peripheral blood mononuclear cells were collected, and RhoA activity and expression were determined by RhoA activation assay kit (G-LISA) and enzyme-linked immunosorbent assay tests, respectively. The severity of aSAH was determined from the World Federation of Neurological Surgeon scale, and vasospasm was evaluated using clinical symptoms, arteriography, and sonography. RhoA expression was significantly increased in peripheral blood mononuclear cells from patients on days 0, 2, and 4 after aSAH versus healthy subjects ( P =0.036, 0.010, and 0.018, respectively, by U Mann-Whitney analysis). There was a significant correlation between RhoA expression and injury severity on days 2 and 4 (Spearman test, day 2: r =0.682, n=14, P =0.007; day 4: r =0.721, n=14, P =0.004). No significant correlation was observed on day 0 (day 0: r =0.131, n=6, P =0.805). Active RhoA was not significantly different in patients and healthy subjects on days 0, 2, and 4 ( P =0.243, 0.222, and 0.600, respectively) nor did it increase significantly on days 0 and 2 in patients with vasospasm versus patients without vasospasm ( P =0.064 and 0.519, respectively). In contrast, active RhoA was significantly higher on day 4 in patients who developed vasospasm versus patients without vasospasm ( P =0.028). Our preliminary results indicate that RhoA expression and activity in peripheral blood mononuclear cells might be related with aSAH severity and cerebral vasospasm. RhoA is a potential biomarker of the risks

RhoA Regulation of Cardiomyocyte Differentiation

PubMed Central

Kaarbø, Mari; Crane, Denis I.; Murrell, Wayne G.

2013-01-01

Earlier findings from our laboratory implicated RhoA in heart developmental processes. To investigate factors that potentially regulate RhoA expression, RhoA gene organisation and promoter activity were analysed. Comparative analysis indicated strict conservation of both gene organisation and coding sequence of the chick, mouse, and human RhoA genes. Bioinformatics analysis of the derived promoter region of mouse RhoA identified putative consensus sequence binding sites for several transcription factors involved in heart formation and organogenesis generally. Using luciferase reporter assays, RhoA promoter activity was shown to increase in mouse-derived P19CL6 cells that were induced to differentiate into cardiomyocytes. Overexpression of a dominant negative mutant of mouse RhoA (mRhoAN19) blocked this cardiomyocyte differentiation of P19CL6 cells and led to the accumulation of the cardiac transcription factors SRF and GATA4 and the early cardiac marker cardiac α-actin. Taken together, these findings indicate a fundamental role for RhoA in the differentiation of cardiomyocytes. PMID:23935420

Activated RhoA Is a Positive Feedback Regulator of the Lbc Family of Rho Guanine Nucleotide Exchange Factor Proteins*

PubMed Central

Medina, Frank; Carter, Angela M.; Dada, Olugbenga; Gutowski, Stephen; Hadas, Jana; Chen, Zhe; Sternweis, Paul C.

2013-01-01

The monomeric Rho GTPases are essential for cellular regulation including cell architecture and movement. A direct mechanism for hormonal regulation of the RhoA-type GTPases is their modulation by the G12 and G13 proteins via RH (RGS homology) containing RhoGEFs. In addition to the interaction of the G protein α subunits with the RH domain, activated RhoA also binds to the pleckstrin homology (PH) domain of PDZRhoGEF. The latter interaction is now extended to all seven members of the homologous Lbc family of RhoGEFs which includes the RH-RhoGEFs. This is evinced by direct measurements of binding or through effects on selected signaling pathways in cells. Overexpression of these PH domains alone can block RhoA-dependent signaling in cells to various extents. Whereas activated RhoA does not modulate the intrinsic activity of the RhoGEFs, activated RhoA associated with phospholipid vesicles can facilitate increased activity of soluble RhoGEFs on vesicle-delimited substrate (RhoA-GDP). This demonstrates feasibility of the hypothesis that binding of activated RhoA to the PH domains acts as a positive feedback mechanism. This is supported by cellular studies in which mutation of this binding site on PH strongly attenuates the stimulation of RhoA observed by overexpression of five of the RhoGEF DH-PH domains. This mutation is even more dramatic in the context of full-length p115RhoGEF. The utilization of this mechanism by multiple RhoGEFs suggests that this regulatory paradigm may be a common feature in the broader family of RhoGEFs. PMID:23493395

The atypical structure and function of newborn arterial endothelium is mediated by Rho/Rho kinase signaling.

PubMed

Flavahan, Sheila; Flavahan, Nicholas A

2014-08-15

Endothelium of fetal or newborn arteries is atypical, displaying actin stress fibers and reduced nitric oxide (NO)-mediated dilatation. This study tested the hypothesis that Rho/Rho kinase signaling, which promotes endothelial stress fibers and inhibits endothelial dilatation, contributed to this phenotype. Carotid arteries were isolated from newborn [postnatal day 1 (P1)], P7, and P21 mice. Endothelial dilatation to acetylcholine (pressure myograph) was minimal at P1, increased at P7, and further increased at P21. Inhibition of Rho (C3 transferase) or Rho kinase (Y27632, fasudil) significantly increased dilatation to acetylcholine in P1 arteries but had no effect in P7 or P21 arteries. After inhibition of NO synthase (N(G)-nitro-l-arginine methyl ester), Rho kinase inhibition no longer increased acetylcholine responses in P1 arteries. Rho kinase inhibition did not affect dilatation to the NO donor DEA-NONOate. The endothelial actin cytoskeleton was labeled with phalloidin and visualized by laser-scanning microscopy. In P1 arteries, the endothelium had prominent transcytoplasmic stress fibers, whereas in P7 and P21 arteries, the actin fibers had a significantly reduced intensity and were restricted to cell borders. Phosphorylation of myosin light chains, a Rho kinase substrate, was highest in P1 endothelium and significantly reduced in P7 and P21 endothelium (laser-scanning microscopy). In P1 arteries, inhibition of Rho (C3 transferase) or Rho kinase (Y27632) significantly reduced the intensity of actin fibers, which were restricted to cell borders. Similarly, in P1 arteries, Rho inhibition significantly reduced endothelial levels of phosphorylated myosin light chains. These results indicate that the atypical function and morphology of newborn endothelium is mediated by Rho/Rho kinase signaling. Copyright © 2014 the American Physiological Society.

The RhoGAP activity of CYK-4/MgcRacGAP functions non-canonically by promoting RhoA activation during cytokinesis

PubMed Central

Zhang, Donglei; Glotzer, Michael

2015-01-01

Cytokinesis requires activation of the GTPase RhoA. ECT-2, the exchange factor responsible for RhoA activation, is regulated to ensure spatiotemporal control of contractile ring assembly. Centralspindlin, composed of the Rho family GTPase-activating protein (RhoGAP) MgcRacGAP/CYK-4 and the kinesin MKLP1/ZEN-4, is known to activate ECT-2, but the underlying mechanism is not understood. We report that ECT-2-mediated RhoA activation depends on the ability of CYK-4 to localize to the plasma membrane, bind RhoA, and promote GTP hydrolysis by RhoA. Defects resulting from loss of CYK-4 RhoGAP activity can be rescued by activating mutations in ECT-2 or depletion of RGA-3/4, which functions as a conventional RhoGAP for RhoA. Consistent with CYK-4 RhoGAP activity contributing to GEF activation, the catalytic domains of CYK-4 and ECT-2 directly interact. Thus, counterintuitively, CYK-4 RhoGAP activity promotes RhoA activation. We propose that the most active form of the cytokinetic RhoGEF involves complex formation between ECT-2, centralspindlin and RhoA. DOI: http://dx.doi.org/10.7554/eLife.08898.001 PMID:26252513

Axial resonances a$$_{1}$$(1260), b$$_{1}$$(1235) and their decays from the lattice

DOE PAGES

Lang, C. B.; Leskovec, Luka; Mohler, Daniel; ...

2014-04-28

The light axial-vector resonancesmore » $$a_1(1260)$$ and $$b_1(1235)$$ are explored in Nf=2 lattice QCD by simulating the corresponding scattering channels $$\\rho\\pi$$ and $$\\omega\\pi$$. Interpolating fields $$\\bar{q} q$$ and $$\\rho\\pi$$ or $$\\omega\\pi$$ are used to extract the s-wave phase shifts for the first time. The $$\\rho$$ and $$\\omega$$ are treated as stable and we argue that this is justified in the considered energy range and for our parameters $$m_\\pi\\simeq 266~$$MeV and $$L\\simeq 2~$$fm. We neglect other channels that would be open when using physical masses in continuum. Assuming a resonance interpretation a Breit-Wigner fit to the phase shift gives the $$a_1(1260)$$ resonance mass $$m_{a1}^{res}=1.435(53)(^{+0}_{-109})$$ GeV compared to $$m_{a1}^{exp}=1.230(40)$$ GeV. The $$a_1$$ width $$\\Gamma_{a1}(s)=g^2 p/s$$ is parametrized in terms of the coupling and we obtain $$g_{a_1\\rho\\pi}=1.71(39)$$ GeV compared to $$g_{a_1\\rho\\pi}^{exp}=1.35(30)$$ GeV derived from $$\\Gamma_{a1}^{exp}=425(175)$$ MeV. In the $$b_1$$ channel, we find energy levels related to $$\\pi(0)\\omega(0)$$ and $$b_1(1235)$$, and the lowest level is found at $$E_1 \\gtrsim m_\\omega+m_\\pi$$ but is within uncertainty also compatible with an attractive interaction. Lastly, assuming the coupling $$g_{b_1\\omega\\pi}$$ extracted from the experimental width we estimate $$m_{b_1}^{res}=1.414(36)(^{+0}_{-83})$$.« less

Crystallization process of zeolite rho prepared by hydrothermal synthesis using 18-crown-6 ether as organic template.

PubMed

Araki, Sadao; Kiyohara, Yasato; Tanaka, Shunsuke; Miyake, Yoshikazu

2012-06-15

There are many viewpoints on the formation mechanisms for zeolites, but the details are not clear. An understanding of the elementary steps for their formation is important for the development of large-scale membranes and efficient manufacturing processes. In this study, the effects of silicon, aluminum, and the incorporation of 18-crown-6 (18C6) ether, on the formation of zeolite rho, using 18C6 as the structure directing agent (SDA) have been investigated by using field emission scanning electron microscopy (FE-SEM), energy dispersive X-ray fluorescence spectrometry (EDX), nuclear magnetic resonance spectroscopy (NMR), thermo gravimetric analysis (TGA), and the pH measurement. These results suggested that a zeolite rho has four synthesis steps; (1) 0-3 h, the dehydration and condensation reaction between the silica and alumina to form amorphous aluminosilicates; (2) 3-20 h, the particle growth and aggregation process for the amorphous aluminosilicates; (3) 20-48 h, the crystallization and crystal growth of zeolite rho, with the incorporation of 18C6; and (4) 48-96 h, gentle growth with an increase in Na/Si ratio and a change in rate for the bounding state between the silica- and the alumina-based species. We consider the above to reflect the four steps for the formation of zeolite rho. Copyright © 2012 Elsevier Inc. All rights reserved.

Pulsatile equibiaxial stretch inhibits thrombin-induced RhoA and NF-{kappa}B activation

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

Haga, Jason H.; Kaunas, Roland; Radeff-Huang, Julie

2008-07-18

This study investigated interactions between the effects of mechanical stretch and thrombin on RhoA activation in rat aortic smooth muscle cells (RASMC). Equibiaxial, pulsatile stretch, or thrombin produced a significant increase in RhoA activation. Surprisingly, in combination, 30 min of stretch inhibited the ability of thrombin to activate RhoA. NO donors and 8-bromo-cGMP significantly inhibited thrombin-induced RhoA activation. Interestingly, the nitric oxide synthase (NOS) inhibitor L-NAME increased basal RhoA activity, suggesting that NOS activity exerts a tonic inhibition on RhoA. Stretching RASMC increases nitrite production, consistent with the idea that NO contributes to the inhibitory effects of stretch. Thrombin stimulatesmore » MAP kinase and NF-{kappa}B pathways through Rho and these responses were blocked by 8-bromo-cGMP or stretch and restored by L-NAME. These data suggest that stretch, acting through NO and cGMP, can prevent the ability of thrombin to stimulate Rho signaling pathways that contribute to pathophysiological proliferative and inflammatory responses.« less

Rho/Rho-dependent kinase affects locomotion and actin-myosin II activity of Amoeba proteus.

PubMed

Kłopocka, W; Redowicz, M J

2004-10-01

The highly motile free-living unicellular organism Amoeba proteus has been widely used as a model to study cell motility. However, the molecular mechanisms underlying its unique locomotion are still scarcely known. Recently, we have shown that blocking the amoebae's endogenous Rac- and Rho-like proteins led to distinct and irreversible changes in the appearance of these large migrating cells as well as to a significant inhibition of their locomotion. In order to elucidate the mechanism of the Rho pathway, we tested the effects of blocking the endogenous Rho-dependent kinase (ROCK) by anti-ROCK antibodies and Y-27632, (+)-(R)-trans-4-(1-aminoethyl)-N-(4-pyridyl)cyclohexanecarboxamide dihydrochloride, a specific inhibitor of ROCK, on migrating amoebae and the effect of the Rho and ROCK inhibition on the actin-activated Mg-ATPase of the cytosolic fraction of the amoebae. Amoebae microinjected with anti-ROCK inhibitors remained contracted and strongly attached to the glass surface and exhibited an atypical locomotion. Despite protruding many pseudopodia that were advancing in various directions, the amoebae could not effectively move. Immunofluorescence studies showed that ROCK-like protein was dispersed throughout the cytoplasm and was also found in the regions of actin-myosin II interaction during both isotonic and isometric contraction. The Mg-ATPase activity was about two- to threefold enhanced, indicating that blocking the Rho/Rho-dependent kinase activated myosin. It is possible then that in contrast to the vertebrate cells, the inactivation of Rho/Rho-dependent kinase in amoebae leads to the activation of myosin II and to the observed hypercontracted cells which cannot exert effective locomotion.

Study of B to pi l nu and B to rho l nu Decays and Determination of |V_ub|

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

del Amo Sanchez, P.; Lees, J.P.; Poireau, V.

2011-12-09

We present an analysis of exclusive charmless semileptonic B-meson decays based on 377 million B{bar B} pairs recorded with the BABAR detector at the {Upsilon} (4S) resonance. We select four event samples corresponding to the decay modes B{sup 0} {yields} {pi}{sup -}{ell}{sup +}{nu}, B{sup +} {yields} {pi}{sup 0}{ell}{sup +}{nu}, B{sup 0} {yields} {rho}{sup -}{ell}{sup +}{nu}, and B{sup +} {yields} {rho}{sup 0}{ell}{sup +}{nu}, and find the measured branching fractions to be consistent with isospin symmetry. Assuming isospin symmetry, we combine the two B {yields} {pi}{ell}{nu} samples, and similarly the two B {yields} {rho}{ell}{nu} samples, and measure the branching fractions {Beta}(B{sup 0}more » {yields} {pi}{sup -}{ell}{sup +}{nu}) = (1.41 {+-} 0.05 {+-} 0.07) x 10{sup -4} and {Beta}(B{sup 0} {yields} {rho}{sup 0}{ell}{sup +}{nu}) = (1.75 {+-} 0.15 {+-} 0.27) x 10{sup -4}, where the errors are statistical and systematic. We compare the measured distribution in q{sup 2}, the momentum transfer squared, with predictions for the form factors from QCD calculations and determine the CKM matrix element |V{sub ub}|. Based on the measured partial branching fraction for B {yields} {pi}{ell}{nu} in the range q{sup 2} < 12 GeV{sup 2} and the most recent LCSR calculations we obtain |V{sub ub}| = (3.78 {+-} 0.13{sub -0.40}{sup +0.55}) x 10{sup -3}, where the errors refer to the experimental and theoretical uncertainties. From a simultaneous fit to the data over the full q{sup 2} range and the FNAL/MILC lattice QCD results, we obtain |V{sub ub}| = (2.95 {+-} 0.31) x 10{sup -3} from B {yields} {pi}{ell}{nu}, where the error is the combined experimental and theoretical uncertainty.« less

Rho/Rho kinase and phosphoinositide 3-kinase are parallel pathways in the development of spontaneous arterial tone in deoxycorticosterone acetate-salt hypertension.

PubMed

Wehrwein, Erica A; Northcott, Carrie A; Loberg, Robert D; Watts, Stephanie W

2004-06-01

Hypertension is characterized by abnormal vascular contractility and function. Arteries from deoxycorticosterone acetate (DOCA)-salt hypertensive rats develop spontaneous tone that is not observed in arteries from normotensive rats. Inhibition of phosphoinositide 3-kinase (PI3-kinase) by 2-(4-morpholinyl)-8-phenyl-4H-1-benzopyran-4-one (LY294002) reduces spontaneous tone development. The Rho/Rho-kinase pathway has been suggested to play a role in hypertension and may be dependent on PI3-kinase activity. We hypothesized that Rhokinase is involved in spontaneous tone development and that Rho/Rho-kinase is a downstream effector of PI3-kinase. Using endothelium-denuded aortic strips in isolated tissue bath, we demonstrated that (+)-(R)-trans-4-(1-aminoethyl)-N-(4-pyridyl) (Y27632) (1 microM), a Rho-kinase inhibitor, significantly reduced spontaneous tone in the DOCA aorta but that it did not affect sham aorta basal tone (DOCA 63.5 +/- 15.9 versus sham 1.2 +/- 0.4 total change in percentage of phenylephrine contraction). We examined the interaction between the PI3-kinase and Rho pathways by observing the effects of LY294002 on a Rhokinase effector, myosin phosphatase (MYPT), and Y27632 on a PI3-kinase effector, Akt, using Western blot analysis. Inhibition of PI3-kinase reduced spontaneous tone, but it had no effect on the phosphorylation status of MYPT, indicating that PI3-kinase is not a downstream effector of Rho/Rho-kinase. These data indicate that there is little interaction between the Rho/Rhokinase and PI3-kinase pathways in the DOCA-salt aorta, and the two pathways seem to operate in parallel in supporting spontaneous arterial tone. These data reflect spontaneous tone only and do not rule out the possibility of interaction between these pathways in agonist-stimulated tone.

Inhibition of RhoA/Rho kinase pathway and smooth muscle contraction by hydrogen sulfide.

PubMed

Nalli, Ancy D; Wang, Hongxia; Bhattacharya, Sayak; Blakeney, Bryan A; Murthy, Karnam S

2017-10-01

Hydrogen sulfide (H 2 S) plays an important role in smooth muscle relaxation. Here, we investigated the expression of enzymes in H 2 S synthesis and the mechanism regulating colonic smooth muscle function by H 2 S. Expression of cystathionine-γ-lyase (CSE), but not cystathionine-β-synthase (CBS), was identified in the colonic smooth muscle of rabbit, mouse, and human. Carbachol (CCh)-induced contraction in rabbit muscle strips and isolated muscle cells was inhibited by l-cysteine (substrate of CSE) and NaHS (an exogenous H 2 S donor) in a concentration-dependent fashion. H 2 S induced S-sulfhydration of RhoA that was associated with inhibition of RhoA activity. CCh-induced Rho kinase activity also was inhibited by l-cysteine and NaHS in a concentration-dependent fashion. Inhibition of CCh-induced contraction by l-cysteine was blocked by the CSE inhibitor, dl-propargylglycine (DL-PPG) in dispersed muscle cells. Inhibition of CCh-induced Rho kinase activity by l-cysteine was blocked by CSE siRNA in cultured cells and DL-PPG in dispersed muscle cells. Stimulation of Rho kinase activity and muscle contraction in response to CCh was also inhibited by l-cysteine or NaHS in colonic muscle cells from mouse and human. Collectively, our studies identified the expression of CSE in colonic smooth muscle and determined that sulfhydration of RhoA by H 2 S leads to inhibition of RhoA and Rho kinase activities and muscle contraction. The mechanism identified may provide novel therapeutic approaches to mitigate gastrointestinal motility disorders. © 2017 The Authors. Pharmacology Research & Perspectives published by John Wiley & Sons Ltd, British Pharmacological Society and American Society for Pharmacology and Experimental Therapeutics.

RhoGAP18B Isoforms Act on Distinct Rho-Family GTPases and Regulate Behavioral Responses to Alcohol via Cofilin

PubMed Central

Kalahasti, Geetha; Rodan, Aylin R.; Rothenfluh, Adrian

2015-01-01

Responses to the effects of ethanol are highly conserved across organisms, with reduced responses to the sedating effects of ethanol being predictive of increased risk for human alcohol dependence. Previously, we described that regulators of actin dynamics, such as the Rho-family GTPases Rac1, Rho1, and Cdc42, alter Drosophila’s sensitivity to ethanol-induced sedation. The GTPase activating protein RhoGAP18B also affects sensitivity to ethanol. To better understand how different RhoGAP18B isoforms affect ethanol sedation, we examined them for their effects on cell shape, GTP-loading of Rho-family GTPase, activation of the actin-severing cofilin, and actin filamentation. Our results suggest that the RhoGAP18B-PA isoform acts on Cdc42, while PC and PD act via Rac1 and Rho1 to activate cofilin. In vivo, a loss-of-function mutation in the cofilin-encoding gene twinstar leads to reduced ethanol-sensitivity and acts in concert with RhoGAP18B. Different RhoGAP18B isoforms, therefore, act on distinct subsets of Rho-family GTPases to modulate cofilin activity, actin dynamics, and ethanol-induced behaviors. PMID:26366560

Sodium and T1rho MRI for molecular and diagnostic imaging of articular cartilage.

PubMed

Borthakur, Arijitt; Mellon, Eric; Niyogi, Sampreet; Witschey, Walter; Kneeland, J Bruce; Reddy, Ravinder

2006-11-01

In this article, both sodium magnetic resonance (MR) and T1rho relaxation mapping aimed at measuring molecular changes in cartilage for the diagnostic imaging of osteoarthritis are reviewed. First, an introduction to structure of cartilage, its degeneration in osteoarthritis (OA) and an outline of diagnostic imaging methods in quantifying molecular changes and early diagnostic aspects of cartilage degeneration are described. The sodium MRI section begins with a brief overview of the theory of sodium NMR of biological tissues and is followed by a section on multiple quantum filters that can be used to quantify both bi-exponential relaxation and residual quadrupolar interaction. Specifically, (i) the rationale behind the use of sodium MRI in quantifying proteoglycan (PG) changes, (ii) validation studies using biochemical assays, (iii) studies on human OA specimens, (iv) results on animal models and (v) clinical imaging protocols are reviewed. Results demonstrating the feasibility of quantifying PG in OA patients and comparison with that in healthy subjects are also presented. The section concludes with the discussion of advantages and potential issues with sodium MRI and the impact of new technological advancements (e.g. ultra-high field scanners and parallel imaging methods). In the theory section on T1rho, a brief description of (i) principles of measuring T1rho relaxation, (ii) pulse sequences for computing T1rho relaxation maps, (iii) issues regarding radio frequency power deposition, (iv) mechanisms that contribute to T1rho in biological tissues and (v) effects of exchange and dipolar interaction on T1rho dispersion are discussed. Correlation of T1rho relaxation rate with macromolecular content and biomechanical properties in cartilage specimens subjected to trypsin and cytokine-induced glycosaminoglycan depletion and validation against biochemical assay and histopathology are presented. Experimental T1rho data from osteoarthritic specimens, animal models

Regulated Localization Is Sufficient for Hormonal Control of Regulator of G Protein Signaling Homology Rho Guanine Nucleotide Exchange Factors (RH-RhoGEFs)*

PubMed Central

Carter, Angela M.; Gutowski, Stephen; Sternweis, Paul C.

2014-01-01

The regulator of G protein signaling homology (RH) Rho guanine nucleotide exchange factors (RhoGEFs) (p115RhoGEF, leukemia-associated RhoGEF, and PDZ-RhoGEF) contain an RH domain and are specific GEFs for the monomeric GTPase RhoA. The RH domains interact specifically with the α subunits of G12 heterotrimeric GTPases. Activated Gα13 modestly stimulates the exchange activity of both p115RhoGEF and leukemia-associated RhoGEF but not PDZ-RhoGEF. Because all three RH-RhoGEFs can localize to the plasma membrane upon expression of activated Gα13, cellular localization of these RhoGEFs has been proposed as a mechanism for controlling their activity. We use a small molecule-regulated heterodimerization system to rapidly control the localization of RH-RhoGEFs. Acute localization of the proteins to the plasma membrane activates RhoA within minutes and to levels that are comparable with activation of RhoA by hormonal stimulation of G protein-coupled receptors. The catalytic activity of membrane-localized RhoGEFs is not dependent on activated Gα13. We further show that the conserved RH domains can rewire two different RacGEFs to activate Rac1 in response to a traditional activator of RhoA. Thus, RH domains act as independent detectors for activated Gα13 and are sufficient to modulate the activity of RhoGEFs by hormones via mediating their localization to substrate, membrane-associated RhoA. PMID:24855647

GPER inhibits diabetes-mediated RhoA activation to prevent vascular endothelial dysfunction.

PubMed

Li, Zilin; Cheng, Liang; Liang, Hongliang; Duan, Weixun; Hu, Jing; Zhi, Weiwei; Yang, Jinbao; Liu, Zhenhua; Zhao, Minggao; Liu, Jincheng

2016-02-01

The effect of estrogen receptors on diabetes-induced vascular dysfunction is critical, but ambiguous. Individuals with diabetic vascular disease may require estrogen receptor-specific targeted therapy in the future. The G protein-coupled estrogen receptor (GPER) has beneficial effects on vascular function. However, its fundamental mechanisms are unclear. The RhoA/Rho-kinase pathway contributes to diabetic vascular complications, whereas estrogen can suppress Rho-kinase function. Thus, we assumed that GPER inhibits diabetes-mediated RhoA activation to prevent vascular dysfunction. We further investigated the underlying mechanisms involved in this process. Vascular endothelial cells and ex vivo cultured ovariectomized (OVX) C57BL/6 mouse aortae were treated with high glucose (HG) alone or in combination with GPER agonist (G1). G1 treatment was also administered to OVX db/db mice for 8 weeks. An ex-vivo isovolumic myograph was used to analyze the endothelium-dependent vasodilation and endothelium-independent contraction of mouse aortae. Apoptosis, oxidative stress, and inflammation were attenuated in G1-pretreated vascular endothelial cells. G1 significantly decreased the phosphorylation of inhibitory endothelial nitric oxide (NO) synthase residue threonine 495 (eNOS Thr495), inhibited RhoA expression, and increased NO production. Additionally, G1 rescued the impaired endothelium-dependent relaxation and inhibited RhoA activation in the thoracic aorta of OVX db/db mice and ex-vivo cultured OVX C57BL/6 mouse aortae treated with HG. Estrogens acting via GPER could protect vascular endothelium, and GPER activation might elicit ERα-independent effect to inhibit RhoA/Rho-kinase pathway. Additionally, GPER activation might reduce vascular smooth muscle contraction by inhibiting RhoA activation. Thus, the results of the present study suggest a new therapeutic paradigm for end-stage vascular dysfunction by inhibiting RhoA/Rho-kinase pathway via GPER activation. Copyright �

Meson electro-/photo-production from QCD

DOE PAGES

Briceno, Raul A.

2016-07-02

I present the calculation of themore » $$\\pi^+\\gamma^\\star\\to\\pi^+\\pi^0$$ transition amplitude from quantum chromodynamics performed by the Hadron Spectrum Collaboration. The amplitude is determined for a range of values of the photon virtuality and the final state energy. One observes a clear dynamical enhancement due to the presence of the $$\\rho$$ resonance. By fitting the transition amplitude and analytically continuing it onto the $$\\rho$$-pole, the $$\\rho\\to\\pi\\gamma^\\star$$ form factor is obtained. This exploratory calculation, performed using lattice quantum chromodynamics, constitutes the very first determination of an electroweak decay of a hadronic resonance directly from the fundamental theory of quarks and gluons. In this talk, I highlight some of the necessary steps that made this calculation possible, placing emphasis on recently developed formalism. In conclusion, I discuss the status and outlook of the field for the study of $$N\\gamma^\\star\\to N^\\star\\to N\\pi$$ transitions.« less

Membrane depolarization-induced RhoA/Rho-associated kinase activation and sustained contraction of rat caudal arterial smooth muscle involves genistein-sensitive tyrosine phosphorylation

PubMed Central

Mita, Mitsuo; Tanaka, Hitoshi; Yanagihara, Hayato; Nakagawa, Jun-ichi; Hishinuma, Shigeru; Sutherland, Cindy; Walsh, Michael P.; Shoji, Masaru

2013-01-01

Rho-associated kinase (ROK) activation plays an important role in K+-induced contraction of rat caudal arterial smooth muscle (Mita et al., Biochem J. 2002; 364: 431–40). The present study investigated a potential role for tyrosine kinase activity in K+-induced RhoA activation and contraction. The non-selective tyrosine kinase inhibitor genistein, but not the src family tyrosine kinase inhibitor PP2, inhibited K+-induced sustained contraction (IC50 = 11.3 ± 2.4 µM). Genistein (10 µM) inhibited the K+-induced increase in myosin light chain (LC20) phosphorylation without affecting the Ca2+ transient. The tyrosine phosphatase inhibitor vanadate induced contraction that was reversed by genistein (IC50 = 6.5 ± 2.3 µM) and the ROK inhibitor Y-27632 (IC50 = 0.27 ± 0.04 µM). Vanadate also increased LC20 phosphorylation in a genistein- and Y-27632-dependent manner. K+ stimulation induced translocation of RhoA to the membrane, which was inhibited by genistein. Phosphorylation of MYPT1 (myosin-targeting subunit of myosin light chain phosphatase) was significantly increased at Thr855 and Thr697 by K+ stimulation in a genistein- and Y-27632-sensitive manner. Finally, K+ stimulation induced genistein-sensitive tyrosine phosphorylation of proteins of ∼55, 70 and 113 kDa. We conclude that a genistein-sensitive tyrosine kinase, activated by the membrane depolarization-induced increase in [Ca2+]i, is involved in the RhoA/ROK activation and sustained contraction induced by K+. Ca2+ sensitization, myosin light chain phosphatase, RhoA, Rho-associated kinase, tyrosine kinase PMID:24133693

Expression of gamma-aminobutyric acid rho 1 and rho 1 Delta 450 as gene fusions with the green fluorescent protein.

PubMed

Martinez-Torres, A; Miledi, R

2001-02-13

The functional characteristics and cellular localization of the gamma aminobutyric acid (GABA) rho 1 receptor and its nonfunctional isoform rho 1 Delta 450 were investigated by expressing them as gene fusions with the enhanced version of the green fluorescent protein (GFP). Oocytes injected with rho 1-GFP had receptors that gated chloride channels when activated by GABA. The functional characteristics of these receptors were the same as for those of wild-type rho 1 receptors. Fluorescence, because of the chimeric receptors expressed, was over the whole oocyte but was more intense near the cell surface and more abundant in the animal hemisphere. Similar to the wild type, rho 1 Delta 450-GFP did not lead to the expression of functional GABA receptors, and injected oocytes failed to generate currents even after exposure to high concentrations of GABA. Nonetheless, the fluorescence displayed by oocytes expressing rho 1 Delta 450-GFP was distributed similarly to that of rho 1-GFP. Mammalian cells transfected with the rho 1-GFP or rho 1 Delta 450-GFP constructs showed mostly intracellularly distributed fluorescence in confocal microscope images. A sparse localization of fluorescence was observed in the plasma membrane regardless of the cell line used. We conclude that rho 1 Delta 450 is expressed and transported close to, and perhaps incorporated into, the plasma membrane. Thus, rho 1- and rho 1 Delta 450-GFP fusions provide a powerful tool to visualize the traffic of GABA type C receptors.

Assessment of the Activation of Rho Family GTP-Binding Proteins in Breast Cancer Cells and Specimens

DTIC Science & Technology

2001-08-01

lymphopenia Vav2 GEF for Rho, Rac, and Cdc42 proto-oncogene product; NM009500 Vav3 GEF for Rho and Rac proto-oncogene product; NM020505 hPEM -2 GEF for...junctions, and desmosomes play a fundamental role in maintaining the polarized phenotype and vectorial transport functions of epithelial cells. The tight

Increased pulmonary RhoA expression in the nitrofen-induced congenital diaphragmatic hernia rat model.

PubMed

Takayasu, Hajime; Masumoto, Kouji; Hagiwara, Koki; Sasaki, Takato; Ono, Kentaro; Jimbo, Takahiro; Uesugi, Toru; Gotoh, Chikashi; Urita, Yasuhisa; Shinkai, Toko; Tanaka, Hideaki

2015-09-01

Persistent pulmonary hypertension remains a major cause of mortality and morbidity in cases of congenital diaphragmatic hernia (CDH). Recently, RhoA/Rho-kinase-mediated vasoconstriction has been reported to be important in the pathogenesis of pulmonary hypertension (PH). Several recent reports have described that fasudil, a potent Rho-kinase inhibitor and vasodilator, could represent a potential therapeutic option for PH. We designed this study to investigate the hypothesis that the expression level of RhoA is increased in the nitrofen-induced CDH rat model. The expression level of Wnt11, an activator of RhoA, was also evaluated. Pregnant rats were treated with or without nitrofen on gestational day 9 (D9). Fetuses were sacrificed on D17, D19 and D21 and were divided into control and CDH groups. Quantitative real-time polymerase chain reaction was performed to determine the pulmonary gene expression levels of both Wnt11 and RhoA. An immunofluorescence study was also performed to evaluate the expression and localization of RhoA. The relative mRNA expression levels of pulmonary Wnt11 and RhoA on D21 were significantly increased in the CDH group compared with the control group (p=0.016 and p=0.008, respectively). The immunofluorescence study confirmed the overexpression of RhoA in the pulmonary vessels of CDH rats on D21. Our results provide evidence that the RhoA/Rho-kinase-mediated pathway is involved in the pathogenesis of PH in the nitrofen-induced CDH rat model. Our data also suggest that the fasudil, a Rho-kinase inhibitor, could represent a therapeutic option for the treatment of PH in CDH. Copyright © 2015 Elsevier Inc. All rights reserved.

{rho}-{omega} mixing and spin dependent charge-symmetry violating potential

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

Biswas, Subhrajyoti; Roy, Pradip; Dutt-Mazumder, Abhee K.

2008-10-15

We construct the charge symmetry violating (CSV) nucleon-nucleon potential induced by the {rho}{sup 0}-{omega} mixing due to the neutron-proton mass difference driven by the NN loop. Analytical expression for the two-body CSV potential is presented containing both the central and noncentral NN interaction. We show that the {rho}NN tensor interaction can significantly enhance the charge symmetry violating NN interaction even if the momentum dependent off-shell {rho}{sup 0}-{omega} mixing amplitude is considered. It is also shown that the inclusion of form factors removes the divergence arising out of the contact interaction. Consequently, we see that the precise size of the computedmore » scattering length difference depends on how the short-range aspects of the CSV potential are treated.« less

Transglutaminase-dependent RhoA activation and depletion by serotonin in vascular smooth muscle cells.

PubMed

Guilluy, Christophe; Rolli-Derkinderen, Malvyne; Tharaux, Pierre-Louis; Melino, Gerry; Pacaud, Pierre; Loirand, Gervaise

2007-02-02

The small G protein RhoA plays a major role in several vascular processes and cardiovascular disorders. Here we analyze the mechanisms of RhoA regulation by serotonin (5-HT) in arterial smooth muscle. 5-HT (0.1-10 microM) induced activation of RhoA followed by RhoA depletion at 24-72 h. Inhibition of 5-HT1 receptors reduced the early phase of RhoA activation but had no effect on 5-HT-induced delayed RhoA activation and depletion, which were suppressed by the 5-HT transporter inhibitor fluoxetine and the transglutaminase inhibitor monodansylcadaverin and in type 2 transglutaminase-deficient smooth muscle cells. Coimmunoprecipitations demonstrated that 5-HT associated with RhoA both in vitro and in vivo. This association was calcium-dependent and inhibited by fluoxetine and monodansylcadaverin. 5-HT promotes the association of RhoA with the E3 ubiquitin ligase Smurf1, and 5-HT-induced RhoA depletion was inhibited by the proteasome inhibitor MG132 and the RhoA inhibitor Tat-C3. Simvastatin, the Rho kinase inhibitor Y-27632, small interfering RNA-mediated RhoA gene silencing, and long-term 5-HT stimulation induced Akt activation. In contrast, inhibition of 5-HT-mediated RhoA degradation by MG132 prevented 5-HT-induced Akt activation. Long-term 5-HT stimulation also led to the inhibition of the RhoA/Rho kinase component of arterial contraction. Our data provide evidence that 5-HT, internalized through the 5-HT transporter, is transamidated to RhoA by transglutaminase. Transamidation of RhoA leads to RhoA activation and enhanced proteasomal degradation, which in turn is responsible for Akt activation and contraction inhibition. The observation of transamidation of 5-HT to RhoA in pulmonary artery of hypoxic rats suggests that this process could participate in pulmonary artery remodeling and hypertension.

Rho-associated coiled-coil containing kinases (ROCK)

PubMed Central

Julian, Linda; Olson, Michael F

2014-01-01

Rho-associated coiled-coil containing kinases (ROCK) were originally identified as effectors of the RhoA small GTPase.1–5 They belong to the AGC family of serine/threonine kinases6 and play vital roles in facilitating actomyosin cytoskeleton contractility downstream of RhoA and RhoC activation. Since their discovery, ROCK kinases have been extensively studied, unveiling their manifold functions in processes including cell contraction, migration, apoptosis, survival, and proliferation. Two mammalian ROCK homologs have been identified, ROCK1 (also called ROCK I, ROKβ, Rho-kinase β, or p160ROCK) and ROCK2 (also known as ROCK II, ROKα, or Rho kinase), hereafter collectively referred to as ROCK. In this review, we will focus on the structure, regulation, and functions of ROCK. PMID:25010901

Identification of a Novel, Putative Rho-specific GDP/GTP Exchange Factor and a RhoA-binding Protein: Control of Neuronal Morphology

PubMed Central

Gebbink, Martijn F.B.G.; Kranenburg, Onno; Poland, Mieke; van Horck, Francis P.G.; Houssa, Brahim; Moolenaar, Wouter H.

1997-01-01

The small GTP-binding protein Rho has been implicated in the control of neuronal morphology. In N1E-115 neuronal cells, the Rho-inactivating C3 toxin stimulates neurite outgrowth and prevents actomyosin-based neurite retraction and cell rounding induced by lysophosphatidic acid (LPA), sphingosine-1-phosphate, or thrombin acting on their cognate G protein–coupled receptors. We have identified a novel putative GDP/GTP exchange factor, RhoGEF (190 kD), that interacts with both wild-type and activated RhoA, but not with Rac or Cdc42. RhoGEF, like activated RhoA, mimics receptor stimulation in inducing cell rounding and in preventing neurite outgrowth. Furthermore, we have identified a 116-kD protein, p116Rip, that interacts with both the GDP- and GTP-bound forms of RhoA in N1E-115 cells. Overexpression of p116Rip stimulates cell flattening and neurite outgrowth in a similar way to dominant-negative RhoA and C3 toxin. Cells overexpressing p116Rip fail to change their shape in response to LPA, as is observed after Rho inactivation. Our results indicate that (a) RhoGEF may link G protein–coupled receptors to RhoA activation and ensuing neurite retraction and cell rounding; and (b) p116Rip inhibits RhoA-stimulated contractility and promotes neurite outgrowth. PMID:9199174

Soft X-ray observation of the Rho Ophiuchus dark cloud region

NASA Technical Reports Server (NTRS)

Apparao, K. M. V.; Hayakawa, S.; Hearn, D. R.

1979-01-01

Soft X-rays (0.1-0.8 keV) from the region including the Rho Oph dark cloud were observed with the SAS-3 low-energy X-ray telescope. No X-ray absorption by the cloud was observed. This indicates that the diffuse component of soft X-rays in this region is mostly from the foreground of the Rho Oph cloud which is located at a distance of 160-200 pc.

Resonance production in the reaction π±p→K s0K ±p at 30 and 50 GeV/ c

NASA Astrophysics Data System (ADS)

Cleland, W. E.; Delfosse, A.; Dorsaz, P.-A.; Gloor, J.-L.; Kienzle-Focacci, M. N.; Mancarella, G.; Martin, A. D.; Martin, M.; Muhlemann, P.; Nef, C.; Pal, T.; Rutschmann, J.; Zeidler, H.

1982-11-01

The mass and momentum transfer spectra of the charged K overlineK system produced in the reaction π±p→K s0K ±p are analyzed. The data have been collected at the CERN SPS with the Geneva-Lausanne two-arm, non-magnetic spectrometer at 30 and 50 GeV/ c incident momenta. The general features of the reactions at these energies and the results of partial-wave analyses of the two kaon system are presented. The channel is dominated by the diffractive production of even spin resonances. The spin 4 recurrence of the A 2(1320) is clearly observed at 2040 MeV ( Γ=380 MeV. A new resonance is observed with a mass M=2450MeV and a width Γ=400 MeV; the quantum numbers of this state are found to be IG( JPC)=1 -(6 ++) . The analysis also shows the decay of the decay of the meson ϱ'(1600) through the K overlineK channel at both energies. The production amplitudes are determined both as a function of the K overlineK effective mass and of the momentum transfer. Isoscalar natural parity exchange is dominant. The energy dependence between 10 and 50 GeV/ c is shown to be well described by a Regge pole model based on the f-dominated pomeron hypothesis. We compare the production mechanisms of the 2 + resonances A 2(1320) and K ∗(1430). Finally, we estimate the K overlineK branching ratios of the spin 4 A 2(2040) and spin 6 A 2(2450) resonances.

MIP-2 causes differential activation of RhoA in mouse aortic versus pulmonary artery endothelial cells

PubMed Central

Moldobaeva, Aigul; Baek, Amy; Wagner, Elizabeth M.

2008-01-01

Previously, we have shown that endothelial cell chemotaxis to the proangiogenic chemokine MIP-2 (macrophage inflammatory protein-2), is much greater in mouse aortic endothelial cells (EC) than pulmonary arterial endothelial cells (PA EC). This was true despite the observation that both cell types display comparable levels of the ligand receptor, CXCR2 (8). Since the systemic arterial circulation is proangiogenic in the adult lung and the pulmonary circulation is relatively resistant to neovascularization, we questioned whether the observed functional heterogeneity is related to inherent differences in cell signaling cascades of the two EC subtypes. Specifically, we measured activation of Rac1 and RhoA, both thought to be involved in EC cell migration. Rac1 showed inconsistent and minimal changes in both cell types after MIP-2 treatment (p>0.05). However, activated RhoA was increased upon exposure to MIP-2 only in aortic EC (61% increase; p<0.05). Decreased RhoA activation after treatment of aortic EC with specific siRNA for RhoA resulted in a functional decrease in EC chemotaxis to MIP-2 (17% increase; p<0.05). Additionally, increased RhoA activation in PA EC with adenoviral infection of RhoA caused an increase in PA EC chemotaxis to MIP-2 (46% increase; p<0.05). Inhibition of RhoA activity with the Rho kinase inhibitor, Y27632 blocked aortic EC chemotaxis and stress fiber formation. Thus, RhoA activation is increased after MIP-2 treatment in mouse aortic endothelial cells but not in pulmonary artery endothelial cells. We conclude that RhoA is part of a signaling pathway essential for aortic cell migration after CXCR2 ligation. This result provides one explanation for the difference in chemotaxis observed in these two endothelial subtypes that express similar levels of CXCR2. PMID:17662312

Rho GTPases at the crossroad of signaling networks in mammals: impact of Rho-GTPases on microtubule organization and dynamics.

PubMed

Wojnacki, José; Quassollo, Gonzalo; Marzolo, María-Paz; Cáceres, Alfredo

2014-01-01

Microtubule (MT) organization and dynamics downstream of external cues is crucial for maintaining cellular architecture and the generation of cell asymmetries. In interphase cells RhoA, Rac, and Cdc42, conspicuous members of the family of small Rho GTPases, have major roles in modulating MT stability, and hence polarized cell behaviors. However, MTs are not mere targets of Rho GTPases, but also serve as signaling platforms coupling MT dynamics to Rho GTPase activation in a variety of cellular conditions. In this article, we review some of the key studies describing the reciprocal relationship between small Rho-GTPases and MTs during migration and polarization.

RhoA-stimulated intra-capillary morphology switch facilitates the arrest of individual circulating tumor cells.

PubMed

Huang, Xi; Yang, Yu; Zhao, Yuwei; Cao, Dan; Ai, Xiaolin; Zeng, Anqi; Gou, Maling; Cai, Lulu; Yang, Hanshuo; Zhao, Chengjian

2018-05-15

Metastasis is the primary cause of death for most cancer patients. Hematogenous arrest of circulating tumor cells (CTCs) is an essential prerequisite for metastases formation. Using transparent transgenic zebrafish (kdrl:eGFP; Casper), together with resonant laser scanning confocal microscopy, we tracked the fate of CTCs in vivo in the blood circulation for days. We found the intra-capillary morphology-switch (ICMS) of individual CTCs from strip to sphere was necessary for their intravascular arrests. Further genetic and pharmacological inhibition experiments indicated that the RhoA signaling was necessary for ICMS and the arrest of CTCs. At last, we demonstrated that early treatment by a clinically approved RhoA/ROCK inhibitor, Fasudil, could efficiently inhibit the initial arrest of individual CTCs and reduce the incidence of tumor metastasis in both zebrafish and mouse models. These results together indicate that RhoA-stimulated ICMS represents a mechanism for the arrest of individual CTCs, providing a potential target for future treatments of hematogenous metastatic disease. © 2017 UICC.

Identification of a GTP-bound Rho specific scFv molecular sensor by phage display selection

PubMed Central

Goffinet, Marine; Chinestra, Patrick; Lajoie-Mazenc, Isabelle; Medale-Giamarchi, Claire; Favre, Gilles; Faye, Jean-Charles

2008-01-01

Background The Rho GTPases A, B and C proteins, members of the Rho family whose activity is regulated by GDP/GTP cycling, function in many cellular pathways controlling proliferation and have recently been implicated in tumorigenesis. Although overexpression of Rho GTPases has been correlated with tumorigenesis, only their GTP-bound forms are able to activate the signalling pathways implicated in tumorigenesis. Thus, the focus of much recent research has been to identify biological tools capable of quantifying the level of cellular GTP-bound Rho, or determining the subcellular location of activation. However useful, these tools used to study the mechanism of Rho activation still have limitations. The aim of the present work was to employ phage display to identify a conformationally-specific single chain fragment variable (scFv) that recognizes the active, GTP-bound, form of Rho GTPases and is able to discriminate it from the inactive, GDP-bound, Rho in endogenous settings. Results After five rounds of phage selection using a constitutively activated mutant of RhoB (RhoBQ63L), three scFvs (A8, C1 and D11) were selected for subsequent analysis. Further biochemical characterization was pursued for the single clone, C1, exhibiting an scFv structure. C1 was selective for the GTP-bound form of RhoA, RhoB, as well as RhoC, and failed to recognize GTP-loaded Rac1 or Cdc42, two other members of the Rho family. To enhance its production, soluble C1 was expressed in fusion with the N-terminal domain of phage protein pIII (scFv C1-N1N2), it appeared specifically associated with GTP-loaded recombinant RhoA and RhoB via immunoprecipitation, and endogenous activated Rho in HeLa cells as determined by immunofluorescence. Conclusion We identified an antibody, C1-N1N2, specific for the GTP-bound form of RhoB from a phage library, and confirmed its specificity towards GTP-bound RhoA and RhoC, as well as RhoB. The success of C1-N1N2 in discriminating activated Rho in

WinRho: Rh immune globulin prepared by ion exchange for intravenous use.

PubMed Central

Bowman, J M; Friesen, A D; Pollock, J M; Taylor, W E

1980-01-01

An Rh immune globulin [Rh IgG] for intravenous use, WinRho, has been prepared by the Winnipeg Rh Institute by a modification of the ion-exchange column method of Hoppe and colleagues. When administered to Rh-negative male and nonpregnant female volunteers WinRho was found to be nonpyrogenic, nontoxic, safe and protective against Rh alloimmunization. In a clinical trial with 240 microgram given at about 28 weeks' gestation and 120 microgram given after delivery to Rh-negative women at risk of Rh immunization WinRho was effective in preventing Rh immunization. Of the 870 women carrying Rh-positive fetuses who were treated with WinRho during pregnancy and were not tested several months after delivery 14 would have shown evidence of Rh immunization by the time of delivery if WinRho had been ineffective; none showed such evidence. Of the 1122 women carrying Rh-positive fetuses who were retested 4 to 6 months after delivery 83 would have shown evidence of Rh immunization at that time if WinRho had been ineffective; only 1 showed such evidence. The efficiency of yield of anti-D with the modified method of production, the fct that it can be given intravenously (a route that causes the patient less discomfort and immediately results in high anti-D levels) and the lower levels of contaminating IgA and IgM make WinRho the preparation of choice for preventing Rh immunization. PMID:6161687

RhoA/Rho-kinase signaling: a therapeutic target in pulmonary hypertension.

PubMed

Barman, Scott A; Zhu, Shu; White, Richard E

2009-01-01

Pulmonary arterial hypertension (PAH) is a devastating disease characterized by progressive elevation of pulmonary arterial pressure and vascular resistance due to pulmonary vasoconstriction and vessel remodeling as well as inflammation. Rho-kinases (ROCKs) are one of the best-described effectors of the small G-protein RhoA, and ROCKs are involved in a variety of cellular functions including muscle cell contraction, proliferation and vascular inflammation through inhibition of myosin light chain phosphatase and activation of downstream mediators. A plethora of evidence in animal models suggests that heightened RhoA/ROCK signaling is important in the pathogenesis of pulmonary hypertension by causing enhanced constriction and remodeling of the pulmonary vasculature. Both animal and clinical studies suggest that ROCK inhibitors are effective for treatment of severe PAH with minimal risk, which supports the premise that ROCKs are important therapeutic targets in pulmonary hypertension and that ROCK inhibitors are a promising new class of drugs for this devastating disease.

Effects of 17β-estradiol and progesterone on the production of adipokines in differentiating 3T3-L1 adipocytes: Role of Rho-kinase.

PubMed

Pektaş, Mehtap; Kurt, Akif Hakan; Ün, İsmail; Tiftik, Rukiye Nalan; Büyükafşar, Kansu

2015-04-01

Effect of female sex hormones on the production/release of adipocyte-derived cytokines has been debatable. Furthermore, whether the cellular signaling triggered by these hormones involve Rho-kinase has not been investigated yet. Therefore, in this study, effects of 17β-estradiol and progesterone as well as the Rho-kinase inhibitor, Y-27632 on the level of adipokines such as resistin, adiponectin, leptin, TNF-α and IL-6 were investigated in 3T3-L1-derived adipocytes. Differentiation was induced in the post-confluent preadipocytes by the standard differentiation medium (Dulbecco's modified Eagle's medium with 10% fetal bovine serum together with the mixture of isobutylmethylxanthine, dexamethasone and insulin) in the presence of 17β-estradiol (10(-8)-10(-7)M), progesterone (10(-6)-10(-5)M), the Rho-kinase inhibitor, Y-27632 (10(-5)M) and their combination for 8days. Measurements of the adipokines were performed in the culturing medium by ELISA kits using specific monoclonal antibodies. 17β-estradiol elevated resistin but decreased adiponectin and IL-6 levels; however, it did not alter the concentration of leptin and TNF-α. Y-27632 pretreatment inhibited the rise of resistin and the fall of adiponectin by 17β-estradiol without any effects by its own. Progesterone did not change resistin, leptin and TNF-α level; however, it elevated adiponectin and decreased IL-6 production. Neither 17β-estradiol nor Y-27632 was able to antagonize the increase of adiponectin and the reduction of IL-6 levels by progesterone. While Y-27632 alone lowered IL-6 level, it increased leptin and TNF-α concentration without altering resistin and adiponectin. In conclusion, 17β-estradiol could modify adipokine production in 3T3-L1 adipocytes with the actions some of which involve Rho-kinase mediation. Copyright © 2015 Elsevier Ltd. All rights reserved.

Expression loss and revivification of RhoB gene in ovary carcinoma carcinogenesis and development.

PubMed

Liu, Yingwei; Song, Na; Ren, Kexing; Meng, Shenglan; Xie, Yao; Long, Qida; Chen, Xiancheng; Zhao, Xia

2013-01-01

RhoB, a member of small GTPases belonging to the Ras protein superfamily, might have a suppressive activity in cancer progression. Here, expression of RhoB gene was evaluated in human benign, borderline and malignant ovary tumors by immunostaining, with normal ovary tissue as control. Malignant tumors were assessed according to Federation Internationale de Gynecologie Obstetrique (FIGO) guidelines and classified in stage I-IV. Revivification of RhoB gene was investigated by analyzing the effect of histone deacetylase (HDAC) inhibitor trichostatin (TSA) and methyltransferase inhibitor 5-azacytidine (5-Aza) on ovarian cancer cells via RT-PCR and western blot. Apoptosis of ovary cancer cells was detected using flowcytometry and fluorescence microscopy. Subsequently, RhoB expression is detected in normal ovary epithelium, borderline tumors, and decreases significantly or lost in the majority of ovarian cancer specimen (P<0.05). RhoB expression decreases significantly from stage II (71.4%) to stage III (43.5%) to stage IV (18.2%, P<0.05). TSA can both significantly revive the RhoB gene and mediate apoptosis of ovarian cancer cells, but 5-Aza couldn't. Interference into Revivification of RhoB gene results in reduction of ovary carcinoma cell apoptosis. It is proposed that loss of RhoB expression occurs frequently in ovary carcinogenesis and progression and its expression could be regulated by histone deacetylation but not by promoter hypermethylation, which may serve as a prospective gene treatment target for the patients with ovarian malignancy not responding to standard therapies.

RhoA GTPase inhibition organizes contraction during epithelial morphogenesis

PubMed Central

Mason, Frank M.; Xie, Shicong; Vasquez, Claudia G.; Tworoger, Michael

2016-01-01

During morphogenesis, contraction of the actomyosin cytoskeleton within individual cells drives cell shape changes that fold tissues. Coordination of cytoskeletal contractility is mediated by regulating RhoA GTPase activity. Guanine nucleotide exchange factors (GEFs) activate and GTPase-activating proteins (GAPs) inhibit RhoA activity. Most studies of tissue folding, including apical constriction, have focused on how RhoA is activated by GEFs to promote cell contractility, with little investigation as to how GAPs may be important. Here, we identify a critical role for a RhoA GAP, Cumberland GAP (C-GAP), which coordinates with a RhoA GEF, RhoGEF2, to organize spatiotemporal contractility during Drosophila melanogaster apical constriction. C-GAP spatially restricts RhoA pathway activity to a central position in the apical cortex. RhoGEF2 pulses precede myosin, and C-GAP is required for pulsation, suggesting that contractile pulses result from RhoA activity cycling. Finally, C-GAP expression level influences the transition from reversible to irreversible cell shape change, which defines the onset of tissue shape change. Our data demonstrate that RhoA activity cycling and modulating the ratio of RhoGEF2 to C-GAP are required for tissue folding. PMID:27551058

Downstream components of RhoA required for signal pathway of superoxide formation during phagocytosis of serum opsonized zymosans in macrophages.

PubMed

Kim, Jun Sub; Kim, Jae Gyu; Jeon, Chan Young; Won, Ha Young; Moon, Mi Young; Seo, Ji Yeon; Kim, Jong Il; Kim, Jaebong; Lee, Jae Yong; Choi, Soo Young; Park, Jinseu; Yoon Park, Jung Han; Ha, Kwon Soo; Kim, Pyeung Hyeun; Park, Jae Bong

2005-12-31

Rac1 and Rac2 are essential for the control of oxidative burst catalyzed by NADPH oxidase. It was also documented that Rho is associated with the superoxide burst reaction during phagocytosis of serum- (SOZ) and IgG-opsonized zymosan particles (IOZ). In this study, we attempted to reveal the signal pathway components in the superoxide formation regulated by Rho GTPase. Tat-C3 blocked superoxide production, suggesting that RhoA is essentially involved in superoxide formation during phagocytosis of SOZ. Conversely SOZ activated both RhoA and Rac1/2. Inhibition of RhoA-activated kinase (ROCK), an important downstream effector of RhoA, by Y27632 and myosin light chain kinase (MLCK) by ML-7 abrogated superoxide production by SOZ. Extracellular signaling-regulated kinase (ERK)1/2 and p38 mitogen-activated protein kinase (MAPK) were activated during phagocytosis of SOZ, and Tat-C3 and SB203580 reduced ERK1/2 and p38 MAPK activation, suggesting that RhoA and p38 MAPK may be upstream regulators of ERK1/2. Inhibition of ERK1/2, p38 MAPK, phosphatidyl inositol 3-kinase did not block translocation of RhoA to membranes, suggesting that RhoA is upstream to these kinases. Inhibition of RhoA by Tat-C3 blocked phosphorylation of p47(PHOX). Taken together, RhoA, ROCK, p38MAPK, ERK1/2, and p47(PHOX) may be subsequently activated, leading to activation of NADPH oxidase to produce superoxide.

Critical functions of RhoB in support of glioblastoma tumorigenesis

PubMed Central

Ma, Yufang; Gong, Yuanying; Cheng, Zhixiang; Loganathan, Sudan; Kao, Crystal; Sarkaria, Jann N.; Abel, Ty W.; Wang, Jialiang

2015-01-01

Background RhoB is a member of the Rho small GTPase family that regulates cytoskeletal dynamics and vesicle trafficking. The RhoB homologs, RhoA and RhoC, have been shown to promote cancer progression and metastasis. In contrast, the functions of RhoB in human cancers are context dependent. Although expression of RhoB inversely correlates with disease progression in several epithelial cancers, recent data suggest that RhoB may support malignant phenotypes in certain cancer types. Methods We assessed RhoB protein levels in glioma surgical specimens and patient-derived xenografts. The roles of RhoB in glioblastoma were determined by loss-of-function and gain-of-function assays in vitro and in vivo. The impact on p53 and STAT3 signaling was investigated. Results RhoB expression was similar in tumor specimens compared with normal neural tissues obtained from epilepsy surgery. RhoB was expressed in the vast majority of xenograft tumors and spheroid cultures. Knockdown of RhoB induced cell-cycle arrest and apoptosis and compromised in vivo tumorigenic potential. However, overexpression of wild-type RhoB or a constitutively active mutant (RhoB-V14) did not significantly affect cell growth, which suggests that RhoB is not a rate-limiting oncogenic factor and is consistent with the scarcity of RhoB mutations in human cancer. Knockdown of RhoB reduced basal STAT3 activity and impaired cytokine-induced STAT3 activation. In glioblastoma tumors retaining wild-type p53, depletion of RhoB also activated p53 and induced expression of p21CIP1/WAF1. Conclusions Our data suggest that RhoB belongs to an emerging class of “nononcogene addiction” factors that are essential for maintenance of malignant phenotypes in human cancers. PMID:25216671

A Conserved RhoGAP Limits M-phase Contractility and Coordinates with Microtubule Asters to Restrict Active RhoA to the Cell Equator During Cytokinesis

PubMed Central

Zanin, Esther; Desai, Arshad; Poser, Ina; Toyoda, Yusuke; Andree, Cordula; Moebius, Claudia; Bickle, Marc; Conradt, Barbara; Piekny, Alisa; Oegema, Karen

2014-01-01

SUMMARY During animal cell cytokinesis, the spindle directs contractile ring assembly by activating RhoA in a narrow equatorial zone. Rapid GTPase activating protein (GAP)-mediated inactivation (RhoA flux) is proposed to limit RhoA zone dimensions. Testing the significance of RhoA flux has been hampered by the fact that the GAP targeting RhoA is not known. Here, we identify M-phase GAP (MP-GAP) as the primary GAP targeting RhoA during mitosis/cytokinesis. MP-GAP inhibition caused excessive RhoA activation in M-phase leading to the uncontrolled formation of large cortical protrusions and late cytokinesis failure. RhoA zone width was broadened by attenuation of the centrosomal asters but was not affected by MP-GAP inhibition alone. Simultaneous aster attenuation and MP-GAP inhibition led to RhoA accumulation around the entire cell periphery. These results identify the major GAP restraining RhoA during cell division and delineate the relative contributions of RhoA flux and centrosomal asters in controlling RhoA zone dimensions. PMID:24012485

Increased Rho kinase activity in congestive heart failure

PubMed Central

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

2012-01-01

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

Measurement of the Michel rho parameter in direct muon decay

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

Piilonen, Leo; Haim, D.; Lee, F. S.

1997-05-20

We report on the status of LAMPF experiment E-1240 to measure the Michel {rho} parameter in direct muon decay. This experiment ran in 1993, and the data are currently being analyzed. The expected precision on the {rho} parameter is {+-}0.0008. This result will provide better constraints on new physics, particularly on the charged vector bosons' mixing angle {zeta} in the manifestly left-right symmetric extension of the Standard Model.

Coupling constant for N*(1535)N{rho}

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

Xie Jujun; Graduate University of Chinese Academy of Sciences, Beijing 100049; Wilkin, Colin

2008-05-15

The value of the N*(1535)N{rho} coupling constant g{sub N*N{rho}} derived from the N*(1535){yields}N{rho}{yields}N{pi}{pi} decay is compared with that deduced from the radiative decay N*(1535){yields}N{gamma} using the vector-meson-dominance model. On the basis of an effective Lagrangian approach, we show that the values of g{sub N*N{rho}} extracted from the available experimental data on the two decays are consistent, though the error bars are rather large.

Expression Loss and Revivification of RhoB Gene in Ovary Carcinoma Carcinogenesis and Development

PubMed Central

Liu, Yingwei; Song, Na; Ren, Kexing; Meng, Shenglan; Xie, Yao; Long, Qida; Chen, Xiancheng; Zhao, Xia

2013-01-01

RhoB, a member of small GTPases belonging to the Ras protein superfamily, might have a suppressive activity in cancer progression. Here, expression of RhoB gene was evaluated in human benign, borderline and malignant ovary tumors by immunostaining, with normal ovary tissue as control. Malignant tumors were assessed according to Federation Internationale de Gynecologie Obstetrique (FIGO) guidelines and classified in stage I-IV. Revivification of RhoB gene was investigated by analyzing the effect of histone deacetylase (HDAC) inhibitor trichostatin (TSA) and methyltransferase inhibitor 5-azacytidine (5-Aza) on ovarian cancer cells via RT-PCR and western blot. Apoptosis of ovary cancer cells was detected using flowcytometry and fluorescence microscopy. Subsequently, RhoB expression is detected in normal ovary epithelium, borderline tumors, and decreases significantly or lost in the majority of ovarian cancer specimen (P<0.05). RhoB expression decreases significantly from stage II (71.4%) to stage III (43.5%) to stage IV (18.2%, P<0.05). TSA can both significantly revive the RhoB gene and mediate apoptosis of ovarian cancer cells, but 5-Aza couldn’t. Interference into Revivification of RhoB gene results in reduction of ovary carcinoma cell apoptosis. It is proposed that loss of RhoB expression occurs frequently in ovary carcinogenesis and progression and its expression could be regulated by histone deacetylation but not by promoter hypermethylation, which may serve as a prospective gene treatment target for the patients with ovarian malignancy not responding to standard therapies. PMID:24223801

Activity-dependent rapid local RhoA synthesis is required for hippocampal synaptic plasticity.

PubMed

Briz, Victor; Zhu, Guoqi; Wang, Yubin; Liu, Yan; Avetisyan, Mariam; Bi, Xiaoning; Baudry, Michel

2015-02-04

Dendritic protein synthesis and actin cytoskeleton reorganization are important events required for the consolidation of hippocampal LTP and memory. However, the temporal and spatial relationships between these two processes remain unclear. Here, we report that treatment of adult rat hippocampal slices with BDNF or with tetraethylammonium (TEA), which induces a chemical form of LTP, produces a rapid and transient increase in RhoA protein levels. Changes in RhoA were restricted to dendritic spines of CA3 and CA1 and require de novo protein synthesis regulated by mammalian target of rapamycin (mTOR). BDNF-mediated stimulation of RhoA activity, cofilin phosphorylation, and actin polymerization were completely suppressed by protein synthesis inhibitors. Furthermore, intrahippocampal injections of RhoA antisense oligodeoxynucleotides inhibited theta burst stimulation (TBS)-induced RhoA upregulation in dendritic spines and prevented LTP consolidation. Addition of calpain inhibitors after BDNF or TEA treatment maintained RhoA levels elevated and prolonged the effects of BDNF and TEA on actin polymerization. Finally, the use of isoform-selective calpain inhibitors revealed that calpain-2 was involved in RhoA synthesis, whereas calpain-1 mediated RhoA degradation. Overall, this mechanism provides a novel link between dendritic protein synthesis and reorganization of the actin cytoskeleton in hippocampal dendritic spines during LTP consolidation. Copyright © 2015 the authors 0270-6474/15/352269-14$15.00/0.

Myc requires RhoA/SRF to reprogram glutamine metabolism.

PubMed

Haikala, Heidi M; Marques, Elsa; Turunen, Mikko; Klefström, Juha

2018-05-04

RhoA regulates actin cytoskeleton but recent evidence suggest a role for this conserved Rho GTPase also in other cellular processes, including transcriptional control of cell proliferation and survival. Interestingy, loss of RhoA is synthetic lethal with oncogenic Myc, a master transcription factor that turns on anabolic metabolism to promote cell growth in many cancers. We show evidence indicating that the synthetic lethal interaction between RhoA loss and Myc arises from deficiency in glutamine utilization, resulting from impaired co-regulation of glutaminase expression and anaplerosis by Myc and RhoA - serum response factor (SRF) pathway. The results suggest metabolic coordination between Myc and RhoA/SRF in sustaining cancer cell viability and indicate RhoA/SRF as a potential vulnerability in cancer cells for therapeutic targeting.

RhoA/rho kinase signaling reduces connexin43 expression in high glucose-treated glomerular mesangial cells with zonula occludens-1 involvement

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

Xie, Xi; Department of Pharmaceutical Engineering, Ocean College, Hainan University, Haikou 570228; Chen, Cheng

RhoA/Rho kinase (ROCK) signaling has been suggested to be involved in diabetic nephropathy (DN) pathogenesis. Altered expression of connexin43 (Cx43) has been found in kidneys of diabetic animals. Both of them have been found to regulate nuclear factor kappa-B (NF-κB) activation in high glucose-treated glomerular mesangial cells (GMCs). The aim of this study was to investigate the relationship between RhoA/ROCK signaling and Cx43 in the DN pathogenesis. We found that upregulation of Cx43 expression inhibited NF-κB p65 nuclear translocation induced by RhoA/ROCK signaling in GMCs. Inhibition of RhoA/ROCK signaling attenuated the high glucose-induced decrease in Cx43. F-actin accumulation and anmore » enhanced interaction between zonula occludens-1 (ZO-1) and Cx43 were observed in high glucose-treated GMCs. ZO-1 depletion or disruption of F-actin formation also inhibited the reduction in Cx43 protein levels induced by high glucose. In conclusion, activated RhoA/ROCK signaling induces Cx43 degradation in GMCs cultured in high glucose, depending on F-actin regulation. Increased F-actin induced by RhoA/ROCK signaling promotes the association between ZO-1 and Cx43, which possibly triggered Cx43 endocytosis, a mechanism of NF-κB activation in high glucose-treated GMCs. - Highlights: • RhoA/ROCK signaling induces Cx43 degradation in GMCs. • F-actin and ZO-1 have functions in the regulation of Cx43 by RhoA/ROCK signaling. • We reveal the relationship between RhoA/ROCK and Cx43 in the activation of NF-κB.« less

Tetramethylpyrazine Protects Against Oxygen-Glucose Deprivation-Induced Brain Microvascular Endothelial Cells Injury via Rho/Rho-kinase Signaling Pathway.

PubMed

Yang, Guang; Qian, Chen; Wang, Ning; Lin, Chenyu; Wang, Yan; Wang, Guangyun; Piao, Xinxin

2017-05-01

Tetramethylpyrazine (TMP, also known as Ligustrazine), which is isolated from Chinese Herb Medicine Ligustium wollichii Franchat (Chuan Xiong), has been widely used in China for the treatment of ischemic stroke by Chinese herbalists. Brain microvascular endothelial cells (BMECs) are the integral parts of the blood-brain barrier (BBB), protecting BMECs against oxygen-glucose deprivation (OGD) which is important for the treatment of ischemic stroke. Here, we investigated the protective mechanisms of TMP, focusing on OGD-injured BMECs and the Rho/Rho-kinase (Rho-associated kinases, ROCK) signaling pathway. The model of OGD-injured BMECs was established in this study. BMECs were identified by von Willebrand factor III staining and exposed to fasudil, or TMP at different concentrations (14.3, 28.6, 57.3 µM) for 2 h before 24 h of OGD injury. The effect of each treatment was examined by cell viability assays, measurement of intracellular reactive oxygen species (ROS), and transendothelial electric resistance and western blot analysis (caspase-3, endothelial nitric oxide synthase (eNOS), RhoA, Rac1). Our results show that TMP significantly attenuated apoptosis and the permeability of BMECs induced by OGD. In addition, TMP could notably down-regulate the characteristic proteins in Rho/ROCK signaling pathway such as RhoA and Rac1, which triggered abnormal changes of eNOS and ROS, respectively. Altogether, our results show that TMP has a strong protective effect against OGD-induced BMECs injury and suggest that the mechanism might be related to the inhibition of the Rho/ROCK signaling pathway.

Use of d-3He proton spectroscopy as a diagnostic of shell rho r in capsule implosion experiments with approximately 0.2 NIF scale high temperature Hohlraums at Omega.

PubMed

Delamater, N D; Wilson, D C; Kyrala, G A; Seifter, A; Hoffman, N M; Dodd, E; Singleton, R; Glebov, V; Stoeckl, C; Li, C K; Petrasso, R; Frenje, J

2008-10-01

We present the calculations and preliminary results from experiments on the Omega laser facility using d-(3)He filled plastic capsule implosions in gold Hohlraums. These experiments aim to develop a technique to measure shell rho r and capsule unablated mass with proton spectroscopy and will be applied to future National Ignition Facility (NIF) experiments with ignition scale capsules. The Omega Hohlraums are 1900 microm length x 1200 microm diameter and have a 70% laser entrance hole. This is approximately a 0.2 NIF scale ignition Hohlraum and reaches temperatures of 265-275 eV similar to those during the peak of the NIF drive. These capsules can be used as a diagnostic of shell rho r, since the d-(3)He gas fill produces 14.7 MeV protons in the implosion, which escape through the shell and produce a proton spectrum that depends on the integrated rho r of the remaining shell mass. The neutron yield, proton yield, and spectra change with capsule shell thickness as the unablated mass or remaining capsule rho r changes. Proton stopping models are used to infer shell unablated mass and shell rho r from the proton spectra measured with different filter thicknesses. The experiment is well modeled with respect to Hohlraum energetics, neutron yields, and x-ray imploded core image size, but there are discrepancies between the observed and simulated proton spectra.

A tip-localized RhoGAP controls cell polarity by globally inhibiting Rho GTPase at the cell apex.

PubMed

Hwang, Jae-Ung; Vernoud, Vanessa; Szumlanski, Amy; Nielsen, Erik; Yang, Zhenbiao

2008-12-23

Highly elongated eukaryotic cells (e.g., neuronal axons, fungal hyphae, and pollen tubes) are generated through continuous apically restricted growth (tip growth), which universally requires tip-localized Rho GTPases. We used the oscillating pollen tube as a model system to determine the function and regulation of Rho GTPases in tip growth. Our previous work showed that the spatiotemporal dynamics of the apical cap of the activated Rho-like GTPase from Plant 1 (ROP1) are critical for tip growth in pollen tubes. However, the underlying mechanism for the generation and maintenance of this dynamic apical cap is poorly understood. A screen for mutations that enhance ROP1-overexpression-induced depolarization of pollen-tube growth identified REN1 (ROP1 enhancer 1) in Arabidopsis, whose null mutations turn elongated pollen tubes into bulbous cells. REN1 encodes a novel Rho GTPase-activating protein (RhoGAP) required for restricting the ROP1 activity to the pollen-tube tip. REN1 was localized to exocytic vesicles accumulated in the pollen-tube apex, as well as to the apical plasma membrane at the site of ROP1 activation. The apical localization of REN1 and its function in controlling growth polarity was compromised by disruption of ROP1-dependent F-actin and vesicular trafficking, which indicates that REN1 targeting and function is regulated by ROP1 downstream signaling. Our findings suggest that the REN1 RhoGAP controls a negative-feedback-based global inhibition of ROP1. This function provides a critical self-organizing mechanism, by which ROP signaling is spatially limited to the growth site and temporally oscillates during continuous tip growth. Similar spatiotemporal control of Rho GTPase signaling may also play an important role in cell-polarity control in other systems, including tip growth in fungi and cell movement in animals.

The Reactions Gamma + Proton ---> Positive Pion Negative Pion Positive Pion Negative Pion Proton and Gamma + Proton ---> KAON(+,-) PION(-,+) Neutral Kaon Proton at 20 GEV

NASA Astrophysics Data System (ADS)

McCrory, Elliott Simkins

The reactions (gamma)p (--->) (pi)('+)(pi)('-)(pi)('+)(pi)(' -)p and (gamma)p (--->) K('(+OR-))(pi)('(-OR+))K('0)p at 20 GeV are studied from data obtained during the BC72 experiment, run at the SLAC 1 meter Hybrid Bubble Chamber facility from 1980 to 1982. The 5702 events in the first channel represent a cross section of 2.54 (+OR-) 0.24 (mu)b; the 235 events in the second channel represent a cross section of 380 (+OR-) 40 nb. The primary radial excitation of the (rho)(770), commonly called the (rho)(1600), is observed in half of the 4(pi) channel, but with parameters markedly different from what has been previously published. Production of the resonance is peripheral, exponential t dependence of 7.5 (GeV)('-2), with s-channel helicity conserved at the 90% level. A variety of methods have been used to calculate the mass and the width of the (rho)' resonance, the strongest (and new for this channel) being a maximum likelihood fit to all aspects of the 4(pi) data. Forty percent of the 4(pi) channel is associated with (DELTA)('++)(1232) production. We have studied, in particular, (gamma)p (--->) A(,n)(DELTA)('++) and see predominantly production of the A(,2) tensor meson resonance with an admixture of the pseudoscalar A(,1) mean resonance. The KK(pi) channel is dominated by K*K production. The K*K system does not appear to be associated with resonance production.

Measurement of the Michel rho parameter in direct muon decay

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

Piilonen, Leo; Haim, D.; Zhang, Y.

1997-05-01

We report on the status of LAMPF experiment E-1240 to measure the Michel {rho} parameter in direct muon decay. This experiment ran in 1993, and the data are currently being analyzed. The expected precision on the {rho} parameter is {plus_minus}0.0008. This result will provide better constraints on new physics, particularly on the charged vector bosons{close_quote} mixing angle {zeta} in the manifestly left-right symmetric extension of the Standard Model. {copyright} {ital 1997 American Institute of Physics.}

Development of qualitative and quantitative analysis methods in pharmaceutical application with new selective signal excitation methods for 13 C solid-state nuclear magnetic resonance using 1 H T1rho relaxation time.

PubMed

Nasu, Mamiko; Nemoto, Takayuki; Mimura, Hisashi; Sako, Kazuhiro

2013-01-01

Most pharmaceutical drug substances and excipients in formulations exist in a crystalline or amorphous form, and an understanding of their state during manufacture and storage is critically important, particularly in formulated products. Carbon 13 solid-state nuclear magnetic resonance (NMR) spectroscopy is useful for studying the chemical and physical state of pharmaceutical solids in a formulated product. We developed two new selective signal excitation methods in (13) C solid-state NMR to extract the spectrum of a target component from such a mixture. These methods were based on equalization of the proton relaxation time in a single domain via rapid intraproton spin diffusion and the difference in proton spin-lattice relaxation time in the rotating frame ((1) H T1rho) of individual components in the mixture. Introduction of simple pulse sequences to one-dimensional experiments reduced data acquisition time and increased flexibility. We then demonstrated these methods in a commercially available drug and in a mixture of two saccharides, in which the (13) C signals of the target components were selectively excited, and showed them to be applicable to the quantitative analysis of individual components in solid mixtures, such as formulated products, polymorphic mixtures, or mixtures of crystalline and amorphous phases. Copyright © 2012 Wiley Periodicals, Inc.

An RNA motif advances transcription by preventing Rho-dependent termination

PubMed Central

Sevostyanova, Anastasia; Groisman, Eduardo A.

2015-01-01

The transcription termination factor Rho associates with most nascent bacterial RNAs as they emerge from RNA polymerase. However, pharmacological inhibition of Rho derepresses only a small fraction of these transcripts. What, then, determines the specificity of Rho-dependent transcription termination? We now report the identification of a Rho-antagonizing RNA element (RARE) that hinders Rho-dependent transcription termination. We establish that RARE traps Rho in an inactive complex but does not prevent Rho binding to its recruitment sites. Although translating ribosomes normally block Rho access to an mRNA, inefficient translation of an open reading frame in the leader region of the Salmonella mgtCBR operon actually enables transcription of its associated coding region by favoring an RNA conformation that sequesters RARE. The discovery of an RNA element that inactivates Rho signifies that the specificity of nucleic-acid binding proteins is defined not only by the sequences that recruit these proteins but also by sequences that antagonize their activity. PMID:26630006

The Role of the Rho/ROCK Pathway in Ang II and TGF-β1-Induced Atrial Remodeling

PubMed Central

Lu, Gui-Hua; Xu, Cheng-Gui; Xu, Zhe; Tang, Kai; Cheng, Yun-Jiu; Gao, Xiu-Ren; Wu, Su-Hua

2016-01-01

Objectives To study the role of the Rho/ROCK pathway in Ang II and TGF-β1-induced atrial remodeling. Methods and Results A canine atrial fibrillation (AF) model was established by rapid atrial pacing (RAP) of the left atrium. The roles of TGF-β1, the RhoA/ROCK signaling pathway and connective tissue growth factor (CTGF) in atrial remodeling were studied via both in vitro and in vivo experiments. Each of the dogs that received RAP developed persistent AF within 4 weeks. The mRNA expression levels of TGF-β1 (1.32±0.38), Collagen-I(1.33±0.91), CTGF(5.83±3.71), RhoA(1.23±0.57) and ROCK-1 (1.02±0.27) in the left atrium were significantly increased following 4 weeks of RAP. Angiotensin II (Ang II) induced the proliferation of atrial fibroblasts and up-regulated the expression of both CTGF and ROCK-1 in a dose-dependent manner. Simvastatin and Y27632 reversed Ang II-induced CFs proliferation, as well as ROCK-1(0.89±0.05 and 1.27±0.03, respectively) and CTGF (0.87±0.04 and 0.91±0.02, respectively) expression. The expression mRNA of ROCK-1(1.74±0.13) and CTGF (2.28±0.11) can upregulated by TGF-β1, and down-regulated by Simvastatin (1.22±0.03 vs 2.27±0.11), Y27632 (1.01±0.04 vs 1.64±0.03), Los (1.04±0.11 vs 1.26±0.05), respectively. Losartan and Simvastatin attenuated the effects of TGF-β1, inhibited RhoA activity as opposed to RhoA protein expression. Y27632 had no effect on either the expression or the activity of RhoA. Conclusions The increased expression of profibrotic factors (CTGF, ROCK1 and Smad2/3) played an important role in our RAP-induced AF model. Increased atrial profibrotic factors involve the activation of either the TGF-β1/RhoA/ROCK-1 or the TGF-β1/Smad2/3 signaling pathway. PMID:27611832

MicroRNA-31 inhibits RhoA-mediated tumor invasion and chemotherapy resistance in MKN-45 gastric adenocarcinoma cells.

PubMed

Korourian, Alireza; Roudi, Raheleh; Shariftabrizi, Ahmad; Madjd, Zahra

2017-12-01

microRNAs are small single-stranded non-coding RNA molecules which modify gene expression by silencing potential target genes. The aberrant expression of RhoA, a small GTPase protein of Rho family, is involved in gastric cancer tumorigenesis. Since miR-31 is a pleomorphic molecule, we evaluated the miR-31/RhoA axis in inducing the malignant phenotype of gastric cancer cells MKN-45. Also, the clinicopathological significance of RhoA was investigated in a well-defined collection of gastric carcinomas which were embedded in tissue microarray blocks. Induction of miR-31 in MKN-45 followed by suppression of RhoA expression resulted in increased sensitivity to 5-fluorouracil, inhibition of cell proliferation, and invasion compared to the control groups. Immunohistochemical analysis in gastric adenocarcinoma patients' samples showed significantly higher expression of RhoA in diffuse versus intestinal subtype tumors ( P = 0.009), poorly differentiated versus well and moderately differentiated tumors ( P = 0.03) and the presence of vascular invasion versus the absence of vascular invasion ( P = 0.04). Our findings suggest a critical role for miR-31, as a tumor suppressor gene, in gastric cancer tumorigenesis by targeting the RhoA. Impact statement Gastric cancer ranks as the third leading cause of cancer-associated deaths worldwide. The RhoA gene encodes a small GTPase protein of Rho family (RhoA) that its dysregulation is associated with cell motility and invasion. A strong line of evidence supports the regulation of RhoA by a number of miRs, including miR-31 in tumors. Our findings revealed that miR-31 is involved in gastric cancer tumorigenesis as a tumor suppressor gene. Through down-regulation of RhoA, miR-31 decreased cell proliferation, migration, and invasion in gastric cancer cells. In addition, induction of miR-31 increased sensitivity to 5-FU; thus, increasing its tissue concentrations could be a potential target for treatment of gastric cancer in the

MicroRNA-31 inhibits RhoA-mediated tumor invasion and chemotherapy resistance in MKN-45 gastric adenocarcinoma cells

PubMed Central

Korourian, Alireza; Roudi, Raheleh; Shariftabrizi, Ahmad

2017-01-01

microRNAs are small single-stranded non-coding RNA molecules which modify gene expression by silencing potential target genes. The aberrant expression of RhoA, a small GTPase protein of Rho family, is involved in gastric cancer tumorigenesis. Since miR-31 is a pleomorphic molecule, we evaluated the miR-31/RhoA axis in inducing the malignant phenotype of gastric cancer cells MKN-45. Also, the clinicopathological significance of RhoA was investigated in a well-defined collection of gastric carcinomas which were embedded in tissue microarray blocks. Induction of miR-31 in MKN-45 followed by suppression of RhoA expression resulted in increased sensitivity to 5-fluorouracil, inhibition of cell proliferation, and invasion compared to the control groups. Immunohistochemical analysis in gastric adenocarcinoma patients’ samples showed significantly higher expression of RhoA in diffuse versus intestinal subtype tumors (P = 0.009), poorly differentiated versus well and moderately differentiated tumors (P = 0.03) and the presence of vascular invasion versus the absence of vascular invasion (P = 0.04). Our findings suggest a critical role for miR-31, as a tumor suppressor gene, in gastric cancer tumorigenesis by targeting the RhoA. Impact statement Gastric cancer ranks as the third leading cause of cancer-associated deaths worldwide. The RhoA gene encodes a small GTPase protein of Rho family (RhoA) that its dysregulation is associated with cell motility and invasion. A strong line of evidence supports the regulation of RhoA by a number of miRs, including miR-31 in tumors. Our findings revealed that miR-31 is involved in gastric cancer tumorigenesis as a tumor suppressor gene. Through down-regulation of RhoA, miR-31 decreased cell proliferation, migration, and invasion in gastric cancer cells. In addition, induction of miR-31 increased sensitivity to 5-FU; thus, increasing its tissue concentrations could be a potential target for treatment of gastric cancer in the

Exclusive Electroproduction of meson rho on the nucleon Virtualite Intermediate With the CLAS Detector at Jlab; Electroproduction Exclusive de meson rho sur le nucleon Virtualite Intermediaire Avec le Detecteur CLAS at Jlab (in French)

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

Hadjidakis, Cynthia

2002-12-17

This report presents the exclusive rho0 meson electroproduction on the nucleon at intermediate square momentum transfers Q 2 (1.5 < Q 2 < 3 GeV 2) and above the resonance region. The experiment has been taken place at the Jefferson laboratory with the CLAS detector, with a 4.2 GeV beam energy on a hydrogen target in the February-March 1999 period. They present the results and in particular the L/T separated cross sections. This experimentally unexplored domain experimentally is at the intersection between traditional ''soft'' hadronic physics models (VDM and Regge inspired models) and ''hard'' pQCD inspired approaches (recently introduced Generalizedmore » Parton Distribution). They discuss both approaches and their domain of validity.« less

Up-regulation of the RhoA/Rho-kinase signaling pathway in corpus cavernosum from endothelial nitric-oxide synthase (NOS), but not neuronal NOS, null mice.

PubMed

Priviero, Fernanda B M; Jin, Li-Ming; Ying, Zhekang; Teixeira, Cleber E; Webb, R Clinton

2010-04-01

We tested the hypothesis that the basal release of nitric oxide (NO) from endothelial cells modulates contractile activity in the corpus cavernosum (CC) via inhibition of the RhoA/Rho-kinase signaling pathway. Cavernosal strips from wild-type (WT), endothelial nitric-oxide synthase knockout [eNOS(-/-)], and neuronal nitric-oxide synthase knockout [nNOS(-/-)] mice were mounted in myographs, and isometric force was recorded. mRNA and protein expression of key molecules in the RhoA/Rho-kinase pathway were analyzed by real-time polymerase chain reaction and Western blot, respectively. The cGMP levels were determined. The Rho-kinase inhibitors (R)-(+)-trans-N-(4-pyridyl)-4-(1-aminoethyl)-cyclohexanecarboxamide (Y-27632) and (S)-(+)-2-methyl-1-[(4-methyl-5-isoquinolinyl)sulfonyl] homopiperazine (H-1152) reduced cavernosal contractions evoked by phenylephrine or electrical field stimulation (EFS) in a concentration-dependent manner, although this inhibition was less effective in tissues from eNOS(-/-) mice. Y-27632 enhanced relaxations induced by sodium nitroprusside, EFS, and NO (administered as acidified NaNO2) without affecting the cGMP content of the cavernosal strips. This enhancement was less prominent in CC from eNOS(-/-). The protein expression of RhoA, Rho-guanine dissociation inhibitor, and Rho-kinase beta did not differ among the strains. However, in eNOS(-/-) CC, the protein expression of Rho-kinase alpha and both mRNA and protein expression of p115-Rho-associated guanine exchange factor (RhoGEF), PDZ-RhoGEF, and leukemia-associated RhoGEF were up-regulated. Phosphorylation of MYPT1 at Thr696 was higher in tissues from eNOS(-/-) mice. A high concentration of Y-27632 significantly enhanced NO release in CC stimulated by EFS. These results suggest a basal release of NO from endothelial cells, which inhibits contractions mediated by the RhoA/Rho-kinase pathway and modulates the expression of proteins related to this pathway in mouse CC. It indicates that

Termination factor Rho: From the control of pervasive transcription to cell fate determination in Bacillus subtilis

PubMed Central

Nicolas, Pierre; Repoila, Francis; Bardowski, Jacek; Aymerich, Stéphane

2017-01-01

In eukaryotes, RNA species originating from pervasive transcription are regulators of various cellular processes, from the expression of individual genes to the control of cellular development and oncogenesis. In prokaryotes, the function of pervasive transcription and its output on cell physiology is still unknown. Most bacteria possess termination factor Rho, which represses pervasive, mostly antisense, transcription. Here, we investigate the biological significance of Rho-controlled transcription in the Gram-positive model bacterium Bacillus subtilis. Rho inactivation strongly affected gene expression in B. subtilis, as assessed by transcriptome and proteome analysis of a rho–null mutant during exponential growth in rich medium. Subsequent physiological analyses demonstrated that a considerable part of Rho-controlled transcription is connected to balanced regulation of three mutually exclusive differentiation programs: cell motility, biofilm formation, and sporulation. In the absence of Rho, several up-regulated sense and antisense transcripts affect key structural and regulatory elements of these differentiation programs, thereby suppressing motility and biofilm formation and stimulating sporulation. We dissected how Rho is involved in the activity of the cell fate decision-making network, centered on the master regulator Spo0A. We also revealed a novel regulatory mechanism of Spo0A activation through Rho-dependent intragenic transcription termination of the protein kinase kinB gene. Altogether, our findings indicate that distinct Rho-controlled transcripts are functional and constitute a previously unknown built-in module for the control of cell differentiation in B. subtilis. In a broader context, our results highlight the recruitment of the termination factor Rho, for which the conserved biological role is probably to repress pervasive transcription, in highly integrated, bacterium-specific, regulatory networks. PMID:28723971

The TAM-family receptor Mer mediates production of HGF through the RhoA-dependent pathway in response to apoptotic cells.

PubMed

Park, Hyun-Jung; Baen, Ji-Yeon; Lee, Ye-Ji; Choi, Youn-Hee; Kang, Jihee Lee

2012-08-01

The TAM receptor protein tyrosine kinases Tyro3, Axl, and Mer play important roles in macrophage function. We investigated the roles of the TAM receptors in mediating the induction of hepatocyte growth factor (HGF) during the interaction of macrophages with apoptotic cells. Mer-specific neutralizing antibody, small interfering RNA (siRNA), and a recombinant Mer protein (Mer/Fc) inhibited HGF mRNA and protein expression, as well as activation of RhoA, Akt, and specific mitogen-activated protein (MAP) kinases in response to apoptotic cells. Inhibition of Axl or Tyro3 with specific antibodies, siRNA, or Fc-fusion proteins did not prevent apoptotic cell-induced HGF mRNA and protein expression and did not inhibit activation of the postreceptor signaling molecules RhoA and certain MAP kinases, including extracellular signal-regulated protein kinase and c-Jun NH(2)-terminal kinase. However, Axl- and Tyro3-specific blockers did inhibit the activation of Akt and p38 MAP kinase in response to apoptotic cells. In addition, none of the TAM receptors mediated the effects of apoptotic cells on transforming growth factor-β or epidermal growth factor mRNA expression. However, they were involved in the induction of vascular endothelial growth factor mRNA expression. Our data provide evidence that when macrophages interact with apoptotic cells, only Mer of the TAM-family receptors is responsible for mediating transcriptional HGF production through a RhoA-dependent pathway.

RhoGTPase Regulators Orchestrate Distinct Stages of Synaptic Development

PubMed Central

Martin-Vilchez, Samuel; Whitmore, Leanna; Asmussen, Hannelore; Zareno, Jessica; Horwitz, Rick; Newell-Litwa, Karen

2017-01-01

Small RhoGTPases regulate changes in post-synaptic spine morphology and density that support learning and memory. They are also major targets of synaptic disorders, including Autism. Here we sought to determine whether upstream RhoGTPase regulators, including GEFs, GAPs, and GDIs, sculpt specific stages of synaptic development. The majority of examined molecules uniquely regulate either early spine precursor formation or later maturation. Specifically, an activator of actin polymerization, the Rac1 GEF β-PIX, drives spine precursor formation, whereas both FRABIN, a Cdc42 GEF, and OLIGOPHRENIN-1, a RhoA GAP, regulate spine precursor elongation. However, in later development, a novel Rac1 GAP, ARHGAP23, and RhoGDIs inactivate actomyosin dynamics to stabilize mature synapses. Our observations demonstrate that specific combinations of RhoGTPase regulatory proteins temporally balance RhoGTPase activity during post-synaptic spine development. PMID:28114311

RHGF-2 Is an Essential Rho-1 Specific RhoGEF that binds to the Multi-PDZ Domain Scaffold Protein MPZ-1 in Caenorhabditis elegans

PubMed Central

Lin, Li; Tran, Thuy; Hu, Shuang; Cramer, Todd; Komuniecki, Richard; Steven, Robert M.

2012-01-01

RhoGEF proteins activate the Rho family of small GTPases and thus play a key role in regulating fundamental cellular processes such as cell morphology and polarity, cell cycle progression and gene transcription. We identified a Caenorhabditis elegans RhoGEF protein, RHGF-2, as a binding partner of the C. elegans multi-PDZ domain scaffold protein MPZ-1 (MUPP1 in mammals). RHGF-2 exhibits significant identity to the mammalian RhoGEFs PLEKHG5/Tech/Syx and contains a class I C-terminal PDZ binding motif (SDV) that interacts most strongly to MPZ-1 PDZ domain eight. RHGF-2 RhoGEF activity is specific to the C. elegans RhoA homolog RHO-1 as determined by direct binding, GDP/GTP exchange and serum response element-driven reporter activity. rhgf-2 is an essential gene since rhgf-2 deletion mutants do not elongate during embryogenesis and hatch as short immobile animals that arrest development. Interestingly, the expression of a functional rhgf-2::gfp transgene appears to be exclusively neuronal and rhgf-2 overexpression results in loopy movement with exaggerated body bends. Transient expression of RHGF-2 in N1E-115 neuroblastoma cells prevents neurite outgrowth similar to constitutive RhoA activation in these cells. Together, these observations indicate neuronally expressed RHGF-2 is an essential RHO-1 specific RhoGEF that binds most strongly to MPZ-1 PDZ domain eight and is required for wild-type C. elegans morphology and growth. PMID:22363657

Hadronic Resonance production in ALICE

NASA Astrophysics Data System (ADS)

Markert, Christina; ALICE Collaboration

2017-07-01

In heavy ion collisions a fireball of hot and dense matter is created. Short lived hadronic resonances are sensitive to the medium properties, in particular to the temperature, density and system size. Resonance yields and momentum distributions are used to gain insight into the hadronic phase, its expansion velocity and time duration. The multiplicity dependent hadronic resonance production in p-p, p-Pb and Pb-Pb collisions will be discussed within the context of the possible extended hadronic and partonic phase. The experimental results will be compared to EPOS+UrQMD model calculations to discuss the system size dependent interactions of the hadronic medium on various resonances. Small systems such as p-p and p-Pb collisions will be discussed with respect to resonance and strange particle measurements.

Regulation of amino acid transport in Escherichia coli by transcription termination factor rho.

PubMed

Quay, S C; Oxender, D L

1977-06-01

Amino acid transport rates and amino acid binding proteins were examined in a strain containing the rho-120 mutation (formerly SuA), which has been shown to lower the rho-dependent, ribonucleic acid-activated adenosine triphosphatase activity to 9% of the rho activity in the isogenic wild-type strain. Tryptophan and proline transport, which occur by membrane-bound systems, were not altered. On the other hand, arginine, histidine, leucine, isoleucine, and valine transport were variably increased by a factor of 1.4 to 5.0. Kinetics of leucine transport showed that the LIV (leucine, isoleucine, and valine)-I (binding protein-associated) transport system is increased 8.5-fold, whereas the LIV-II (membrane-bound) system is increased 1.5-fold in the rho mutant under leucine-limited growth conditions. The leucine binding protein is increased fourfold under the same growth conditions. The difference in leucine transport in these strains was greatest during leucine-limited growth; growth on complex media repressed both strains to the same transport activity. We propose that rho-dependent transcriptional termination is important for leucine-specific repression of branched-chain amino acid transport, although rho-independent regulation, presumably by a corepressor-aporepressor-type mechanism, must also occur.

PKCε Phosphorylates and Mediates the Cell Membrane Localization of RhoA

PubMed Central

Su, Tizhi; Bao, Liwei; Xie, Xiujie; Lehner, Caryn L.; Cavey, Greg S.; Teknos, Theodoros N.

2013-01-01

Protein kinase Cε (PKCε) signals through RhoA to modulate cell invasion and motility. In this study, the multifaceted interaction between PKCε and RhoA was defined. Phosphopeptide mapping revealed that PKCε phosphorylates RhoA at T127 and S188. Recombinant PKCε bound to recombinant RhoA in the absence of ATP indicating that the association between PKCε and RhoA does not require an active ATP-docked PKCε conformation. Activation of PKCε resulted in a dramatic coordinated translocation of PKCε and RhoA from the cytoplasm to the cell membrane using time-lapse fluorescence microscopy. Stoichiometric FRET analysis revealed that the molecular interaction between PKCε and RhoA is a biphasic event, an initial peak at the cytoplasm and a gradual prolonged increase at the cell membrane for the entire time-course (12.5 minutes). These results suggest that the PKCε-RhoA complex is assembled in the cytoplasm and subsequently recruited to the cell membrane. Kinase inactive (K437R) PKCε is able to recruit RhoA to the cell membrane indicating that the association between PKCε and RhoA is proximal to the active catalytic site and perhaps independent of a PKCε-RhoA phosphorylation event. This work demonstrates, for the first time, that PKCε phosphorylates and modulates the cell membrane translocation of RhoA. PMID:24191200

Citron kinase controls abscission through RhoA and anillin

PubMed Central

Gai, Marta; Camera, Paola; Dema, Alessandro; Bianchi, Federico; Berto, Gaia; Scarpa, Elena; Germena, Giulia; Di Cunto, Ferdinando

2011-01-01

The small GTPase RhoA plays a crucial role in the different stages of cytokinesis, including contractile ring formation, cleavage furrow ingression, and midbody abscission. Citron kinase (CIT-K), a protein required for cytokinesis and conserved from insects to mammals, is currently considered a cytokinesis-specific effector of active RhoA. In agreement with previous observations, we show here that, as in Drosophila cells, CIT-K is specifically required for abscission in mammalian cells. However, in contrast with the current view, we provide evidence that CIT-K is an upstream regulator rather than a downstream effector of RhoA during late cytokinesis. In addition, we show that CIT-K is capable of physically and functionally interacting with the actin-binding protein anillin. Active RhoA and anillin are displaced from the midbody in CIT-K-depleted cells, while only anillin, but not CIT-K, is affected if RhoA is inactivated in late cytokinesis. The overexpression of CIT-K and of anillin leads to abscission delay. However, the delay produced by CIT-K overexpression can be reversed by RhoA inactivation, while the delay produced by anillin overexpression is RhoA-independent. Altogether, these results indicate that CIT-K is a crucial abscission regulator that may promote midbody stability through active RhoA and anillin. PMID:21849473

Assessment of the Activation State of Rho Family GTP-Binding Proteins in Breast Cancer Cells and Specimens

DTIC Science & Technology

2004-08-01

AF038388 Vav3 GEF for Rho and Rac Proto-oncogene product NM020505 hPEM -2 GEF for Cdc42 Predominantly expressed in brain AB007884 GEF-H1 GEF for Rac and Rho...fence tions, and desmosomes play a fundamental role in maintain- function). A functional tight junction is crucial to maintain ing the polarized phenotype

RhoA/ROCK downregulates FPR2-mediated NADPH oxidase activation in mouse bone marrow granulocytes.

PubMed

Filina, Julia V; Gabdoulkhakova, Aida G; Safronova, Valentina G

2014-10-01

Polymorphonuclear neutrophils (PMNs) express the high and low affinity receptors to formylated peptides (mFPR1 and mFPR2 in mice, accordingly). RhoA/ROCK (Rho activated kinase) pathway is crucial for cell motility and oxidase activity regulated via FPRs. There are contradictory data on RhoA-mediated regulation of NADPH oxidase activity in phagocytes. We have shown divergent Rho GTPases signaling via mFPR1 and mFPR2 to NADPH oxidase in PMNs from inflammatory site. The present study was aimed to find out the role of RhoA/ROCK in the respiratory burst activated via mFPR1 and mFPR2 in the bone marrow PMNs. Different kinetics of RhoA activation were detected with 0.1μM fMLF and 1μM WKYMVM operating via mFPR1 and mFPR2, accordingly. RhoA was translocated in fMLF-activated cells towards the cell center and juxtamembrane space versus uniform allocation in the resting cells. Specific inhibition of RhoA by CT04, Rho inhibitor I, weakly depressed the respiratory burst induced via mFPR1, but significantly increased the one induced via mFPR2. Inhibition of ROCK, the main effector of RhoA, by Y27632 led to the same effect on the respiratory burst. Regulation of mFPR2-induced respiratory response by ROCK was impossible under the cytoskeleton disruption by cytochalasin D, whereas it persisted in the case of mFPR1 activation. Thus we suggest RhoA to be one of the regulatory and signal transduction components in the respiratory burst through FPRs in the mouse bone marrow PMNs. Both mFPR1 and mFPR2 binding with a ligand trigger the activation of RhoA. FPR1 signaling through RhoA/ROCK increases NADPH-oxidase activity. But in FPR2 action RhoA/ROCK together with cytoskeleton-linked systems down-regulates NADPH-oxidase. This mechanism could restrain the reactive oxygen species dependent damage of own tissues during the chemotaxis of PMNs and in the resting cells. Copyright © 2014 Elsevier Inc. All rights reserved.

Viral Activation of MK2-hsp27-p115RhoGEF-RhoA Signaling Axis Causes Cytoskeletal Rearrangements, P-body Disruption and ARE-mRNA Stabilization

PubMed Central

Corcoran, Jennifer A.; Johnston, Benjamin P.; McCormick, Craig

2015-01-01

Kaposi's sarcoma-associated herpesvirus (KSHV) is the infectious cause of several AIDS-related cancers, including the endothelial cell (EC) neoplasm Kaposi's sarcoma (KS). KSHV-infected ECs secrete abundant host-derived pro-inflammatory molecules and angiogenic factors that contribute to tumorigenesis. The precise contributions of viral gene products to this secretory phenotype remain to be elucidated, but there is emerging evidence for post-transcriptional regulation. The Kaposin B (KapB) protein is thought to contribute to the secretory phenotype in infected cells by binding and activating the stress-responsive kinase MK2, thereby selectively blocking decay of AU-rich mRNAs (ARE-mRNAs) encoding pro-inflammatory cytokines and angiogenic factors. Processing bodies (PBs) are cytoplasmic ribonucleoprotein foci in which ARE-mRNAs normally undergo rapid 5′ to 3′ decay. Here, we demonstrate that PB dispersion is a feature of latent KSHV infection, which is dependent on kaposin protein expression. KapB is sufficient to disperse PBs, and KapB-mediated ARE-mRNA stabilization could be partially reversed by treatments that restore PBs. Using a combination of genetic and chemical approaches we provide evidence that KapB-mediated PB dispersion is dependent on activation of a non-canonical Rho-GTPase signaling axis involving MK2, hsp27, p115RhoGEF and RhoA. PB dispersion in latently infected cells is likewise dependent on p115RhoGEF. In addition to PB dispersion, KapB-mediated RhoA activation in primary ECs caused actin stress fiber formation, increased cell motility and angiogenesis; these effects were dependent on the activity of the RhoA substrate kinases ROCK1/2. By contrast, KapB-mediated PB dispersion occurred in a ROCK1/2-independent manner. Taken together, these observations position KapB as a key contributor to viral reprogramming of ECs, capable of eliciting many of the phenotypes characteristic of KS tumor cells, and strongly contributing to the post

RhoG protein regulates platelet granule secretion and thrombus formation in mice.

PubMed

Goggs, Robert; Harper, Matthew T; Pope, Robert J; Savage, Joshua S; Williams, Christopher M; Mundell, Stuart J; Heesom, Kate J; Bass, Mark; Mellor, Harry; Poole, Alastair W

2013-11-22

Rho GTPases such as Rac, RhoA, and Cdc42 are vital for normal platelet function, but the role of RhoG in platelets has not been studied. In other cells, RhoG orchestrates processes integral to platelet function, including actin cytoskeletal rearrangement and membrane trafficking. We therefore hypothesized that RhoG would play a critical role in platelets. Here, we show that RhoG is expressed in human and mouse platelets and is activated by both collagen-related peptide (CRP) and thrombin stimulation. We used RhoG(-/-) mice to study the function of RhoG in platelets. Integrin activation and aggregation were reduced in RhoG(-/-) platelets stimulated by CRP, but responses to thrombin were normal. The central defect in RhoG(-/-) platelets was reduced secretion from α-granules, dense granules, and lysosomes following CRP stimulation. The integrin activation and aggregation defects could be rescued by ADP co-stimulation, indicating that they are a consequence of diminished dense granule secretion. Defective dense granule secretion in RhoG(-/-) platelets limited recruitment of additional platelets to growing thrombi in flowing blood in vitro and translated into reduced thrombus formation in vivo. Interestingly, tail bleeding times were normal in RhoG(-/-) mice, suggesting that the functions of RhoG in platelets are particularly relevant to thrombotic disorders.

Partial contribution of Rho-kinase inhibition to the bioactivity of Ganoderma lingzhi and its isolated compounds: insights on discovery of natural Rho-kinase inhibitors.

PubMed

Amen, Yhiya; Zhu, Qinchang; Tran, Hai-Bang; Afifi, Mohamed S; Halim, Ahmed F; Ashour, Ahmed; Shimizu, Kuniyoshi

2017-04-01

Recent studies identified Rho-kinase enzymes (ROCK-I and ROCK-II) as important targets that are involved in a variety of diseases. Synthetic Rho-kinase inhibitors have emerged as potential therapeutic agents to treat disorders such as hypertension, stroke, cancer, diabetes, glaucoma, etc. Our study is the first to screen the total ethanol extract of the medicinal mushroom Ganoderma lingzhi with thirty-five compounds for Rho-kinase inhibitory activity. Moreover, a molecular binding experiment was designed to investigate the binding affinity of the compounds at the active sites of Rho-kinase enzymes. The structure-activity relationship analysis was investigated. Our results suggest that the traditional uses of G. lingzhi might be in part due to the ROCK-I and ROCK-II inhibitory potential of this mushroom. Structure-activity relationship studies revealed some interesting features of the lanostane triterpenes that potentiate their Rho-kinase inhibition. These findings would be helpful for further studies on the design of Rho-kinase inhibitors from natural sources and open the door for contributions from other researchers for optimizing the development of natural Rho-kinase inhibitors.

Role of Rho-mediated ROCK-Semaphorin3A signaling pathway in the pathogenesis of Parkinson's disease in a mouse model.

PubMed

Qi, Li; Tang, Yong-Gang; Wang, Lin; He, Wei; Pan, Hong-Hua; Nie, Rong-Rong; Can, Yan

2016-11-15

The present study aims to elucidate the role of Rho-mediated ROCK-Semaphorin3A signaling pathway in the pathogenesis of Parkinson's disease (PD) in a mouse model. One-hundred twelve eight-week male C57BL/6 mice were selected. The mouse model of PD was constructed by intraperitoneal injection of MPTP. All mice were divided into four groups (28 mice in each group): Blank group, Model group, Rho knockout (Rho+/-) group and ROCK knockout (ROCK+/-) group. Changes of behavior of the mice were studied through automatic moving test and rotarod test. Immunohistochemistry (IHC) was used to detect the expressions of TH, CD11b and GFAP. High performance liquid chromatograph (HPLC) was performed for detection of dopamine and its metabolic product. The mRNA and protein expressions of Rho, ROCK, Sema3A, PlexinA and NRP-1 were detected using quantitative real-time polymerase chain reaction (qRT-PCR) and Western blotting. Rho and ROCK knockout improved the damage caused by MPTP on the behavior of mice and protected dopaminergic neurons from injury, along with the increases of dopamine and its metabolic product. The mRNA and protein expressions of Rho, ROCK, Sema3A, PlexinA and NRP-1 were increased in PD mice in the Model group compared with those in the Blank group. Compared to the Model group, the mRNA and protein expressions of Rho, ROCK, Sema3A, PlexinA and NRP-1 were reduced in the Rho+/- and ROCK+/- groups. These findings indicate that Rho and ROCK knockout may improve the behavior of mice and prevent MPTP-induced dopaminergic neurons damage by regulating Sema3A, PlexinA and NRP-1 in a mouse model of PD. Copyright © 2016 Elsevier B.V. All rights reserved.

Grb2 mediates semaphorin-4D-dependent RhoA inactivation.

PubMed

Sun, Tianliang; Krishnan, Rameshkumar; Swiercz, Jakub M

2012-08-01

Signaling through the semaphorin 4D (Sema4D) receptor plexin-B1 is modulated by its interaction with tyrosine kinases ErbB-2 and Met. In cells expressing the plexin-B1-ErbB-2 receptor complex, ligand stimulation results in the activation of small GTPase RhoA and stimulation of cellular migration. By contrast, in cells expressing plexin-B1 and Met, ligand stimulation results in an association with the RhoGTPase-activating protein p190 RhoGAP and subsequent RhoA inactivation--a process that involves the tyrosine phosphorylation of plexin-B1 by Met. Inactivation of RhoA is necessary for Sema4D-mediated inhibition of cellular migration. It is, however, unknown how plexin-B1 phosphorylation regulates RhoGAP interaction and activity. Here we show that the activation of plexin-B1 by Sema4D and its subsequent tyrosine phosphorylation by Met creates a docking site for the SH2 domain of growth factor receptor bound-2 (Grb2). Grb2 is thereby recruited into the plexin-B1 receptor complex and, through its SH3 domain, interacts with p190 RhoGAP and mediates RhoA deactivation. Phosphorylation of plexin-B1 by Met and the recruitment of Grb2 have no effect on the R-RasGAP activity of plexin-B1, but are required for Sema4D-induced, RhoA-dependent antimigratory effects of Sema4D on breast cancer cells. These data show Grb2 as a direct link between plexin and p190-RhoGAP-mediated downstream signaling.

Topographical Variation of Human Femoral Articular Cartilage Thickness, T1rho and T2 Relaxation Times Is Related to Local Loading during Walking.

PubMed

Van Rossom, Sam; Wesseling, Mariska; Van Assche, Dieter; Jonkers, Ilse

2018-01-01

Objective Early detection of degenerative changes in the cartilage matrix composition is essential for evaluating early interventions that slow down osteoarthritis (OA) initiation. T1rho and T2 relaxation times were found to be effective for detecting early changes in proteoglycan and collagen content. To use these magnetic resonance imaging (MRI) methods, it is important to document the topographical variation in cartilage thickness, T1rho and T2 relaxation times in a healthy population. As OA is partially mechanically driven, the relation between these MRI-based parameters and localized mechanical loading during walking was investigated. Design MR images were acquired in 14 healthy adults and cartilage thickness and T1rho and T2 relaxation times were determined. Experimental gait data was collected and processed using musculoskeletal modeling to identify weight-bearing zones and estimate the contact force impulse during gait. Variation of the cartilage properties (i.e., thickness, T1rho, and T2) over the femoral cartilage was analyzed and compared between the weight-bearing and non-weight-bearing zone of the medial and lateral condyle as well as the trochlea. Results Medial condyle cartilage thickness was correlated to the contact force impulse ( r = 0.78). Lower T1rho, indicating increased proteoglycan content, was found in the medial weight-bearing zone. T2 was higher in all weight-bearing zones compared with the non-weight-bearing zones, indicating lower relative collagen content. Conclusions The current results suggest that medial condyle cartilage is adapted as a long-term protective response to localized loading during a frequently performed task and that the weight-bearing zone of the medial condyle has superior weight bearing capacities compared with the non-weight-bearing zones.

Involvement of Rho kinase in the pathogenesis of acute pulmonary embolism-induced polystyrene microspheres in rats.

PubMed

Toba, M; Nagaoka, T; Morio, Y; Sato, K; Uchida, K; Homma, N; Takahashi, K

2010-03-01

Acute pulmonary embolism (PE) is a life-threatening disease, and several vasoconstrictors, including endothelin-1 (ET-1), play a key role in vasoconstriction and hypoxemia during the development of PE. Rho kinase is activated by various vasoconstrictors resulting in vascular contraction and remodeling. Recent evidence has revealed an important role of Rho kinase in the pathogenesis of systemic and pulmonary vascular diseases. However, contribution of Rho kinase in PE remains unclear. We thus investigated the role of Rho kinase in the PE rat model induced by intrajugular administration of polystyrene microspheres (mean diameter, 26 microm). At 6 h following the administration of microspheres (1.5 ml/kg), right ventricular systolic pressure (RVSP) was higher in the PE than in the control rats (15.8 +/- 1.6 vs. 32.9 +/- 7.5 mmHg). Arterial oxygen tension was lower (92.3 +/- 12.5 vs. 66.0 +/- 17.7 Torr), and alveolar-arterial difference in oxygen partial pressure was higher (3.9 +/- 3.8 vs. 36.5 +/- 26.9 Torr) in the PE rats. Western blotting analysis revealed upregulation and downregulation in expression of vascular cell adhesion molecule-1 and endothelial nitric oxide synthase in lungs from the PE rats, respectively, and radioimmunoassay demonstrated an increase in plasma ET-1 levels. Lung Rho kinase alpha expression was greater in the PE rats. At 5 h following administration of microspheres (0.75 ml/kg), intravenous Rho kinase inhibitors HA1077 and Y27632 (3 mg/kg each) attenuated elevation of RVSP (22.0 +/- 3.7, 17.1 +/- 3.2, 14.3 +/- 2.6 mmHg, PE, PE+HA1077, PE+Y27632) and the severity of hypoxemia (66.3 +/- 16.2, 94.9 +/- 23.0, 89.1 +/- 8.5 Torr, PE, PE+HA1077, PE+Y27632) in the PE rats. These results suggest that pulmonary endothelial dysfunction and activation of Rho kinase may contribute to the potentiation of vasoconstriction and hypoxemia in the PE rats.

RhoC and ROCKs regulate cancer cell interactions with endothelial cells.

PubMed

Reymond, Nicolas; Im, Jae Hong; Garg, Ritu; Cox, Susan; Soyer, Magali; Riou, Philippe; Colomba, Audrey; Muschel, Ruth J; Ridley, Anne J

2015-06-01

RhoC is a member of the Rho GTPase family that is implicated in cancer progression by stimulating cancer cell invasiveness. Here we report that RhoC regulates the interaction of cancer cells with vascular endothelial cells (ECs), a crucial step in the metastatic process. RhoC depletion by RNAi reduces PC3 prostate cancer cell adhesion to ECs, intercalation between ECs as well as transendothelial migration in vitro. Depletion of the kinases ROCK1 and ROCK2, two known RhoC downstream effectors, similarly decreases cancer interaction with ECs. RhoC also regulates the extension of protrusions made by cancer cells on vascular ECs in vivo. Transient RhoC depletion is sufficient to reduce both early PC3 cell retention in the lungs and experimental metastasis formation in vivo. Our results indicate RhoC plays a central role in cancer cell interaction with vascular ECs, which is a critical event for cancer progression. Copyright © 2015 The Authors. Published by Elsevier B.V. All rights reserved.

p120Ras-GAP binds the DLC1 Rho-GAP tumor suppressor protein and inhibits its RhoA GTPase and growth-suppressing activities.

PubMed

Yang, X-Y; Guan, M; Vigil, D; Der, C J; Lowy, D R; Popescu, N C

2009-03-19

DLC1 (deleted in liver cancer 1), which encodes a Rho GTPase-activating protein (Rho-GAP), is a potent tumor suppressor gene that is frequently inactivated in several human cancers. DLC1 is a multidomain protein that has been shown previously to bind members of the tensin gene family. Here we show that p120Ras-GAP (Ras-GAP; also known as RASA1) interacts and extensively colocalizes with DLC1 in focal adhesions. The binding was mapped to the SH3 domain located in the N terminus of Ras-GAP and to the Rho-GAP catalytic domain located in the C terminus of the DLC1. In vitro analyses with purified proteins determined that the isolated Ras-GAP SH3 domain inhibits DLC1 Rho-GAP activity, suggesting that Ras-GAP is a negative regulator of DLC1 Rho-GAP activity. Consistent with this possibility, we found that ectopic overexpression of Ras-GAP in a Ras-GAP-insensitive tumor line impaired the growth-suppressing activity of DLC1 and increased RhoA activity in vivo. Our observations expand the complexity of proteins that regulate DLC1 function and define a novel mechanism of the cross talk between Ras and Rho GTPases.1R01CA129610

Rho/Rock cross-talks with transforming growth factor-β/Smad pathway participates in lung fibroblast-myofibroblast differentiation.

PubMed

Ji, Hong; Tang, Haiying; Lin, Hongli; Mao, Jingwei; Gao, Lili; Liu, Jia; Wu, Taihua

2014-11-01

The differentiation of fibroblasts, which are promoted by transforming growth factor-β (TGF-β)/Smad, is involved in the process of pulmonary fibrosis. The Rho/Rho-associated coiled-coil-forming protein kinase (Rock) pathway may regulate the fibroblast differentiation and myofibroblast expression of α-smooth muscle actin (α-SMA), however, the mechanism is not clear. The aim of the present study was to evaluate the role of Rho/Rock and TGF-β/Smad in TGF-β1-induced lung fibroblasts differentiation. Human embryonic lung fibroblasts were stimulated by TGF-β1, Y-27632 (inhibitor of Rho/Rock signaling) and staurosporine (inhibitor of TGF-β/Smad signaling). The α-SMA expression, cell cycle progression, content of the extracellular matrix (ECM) in cell culture supernatants and the expression of RhoA, RhoC, Rock1 and Smad2 were detected. The results demonstrated that α-SMA-positive cells significantly increased following TGF-β1 stimulation. Rho/Rock and TGF-β/Smad inhibitors suppressed TGF-β1-induced lung fibroblast differentiation. The inhibitors increased G 0 /G 1 and decreased S and G 2 /M percentages. The concentrations of the ECM proteins in the supernatant were significantly increased by TGF-β1 stimulation, whereas they were decreased by inhibitor stimulation. RhoA, RhoC, Rock1, Smad2 and tissue inhibitor of metalloproteinase-1 were upregulated by TGF-β1 stimulation. The Rho/Rock inhibitor downregulated Smad2 expression and the TGF-β/Smad inhibitor downregulated RhoA, RhoC and Rock1 expression. Therefore, the Rho/Rock pathway and Smad signaling were involved in the process of lung fibroblasts transformation, induced by TGF-β1, to myofibroblasts. The two pathways may undergo cross-talk in the lung fibroblasts differentiation in vitro .

REVISITING {rho}{sup 1} CANCRI e: A NEW MASS DETERMINATION OF THE TRANSITING SUPER-EARTH

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

Endl, Michael; Cochran, William D.; MacQueen, Phillip J.

2012-11-01

We present a mass determination for the transiting super-Earth {rho}{sup 1} Cancri e based on nearly 700 precise radial velocity (RV) measurements. This extensive RV data set consists of data collected by the McDonald Observatory planet search and published data from Lick and Keck observatories. We obtained 212 RV measurements with the Tull Coude Spectrograph at the Harlan J. Smith 2.7 m Telescope and combined them with a new Doppler reduction of the 131 spectra that we have taken in 2003-2004 with the High-Resolution Spectrograph (HRS) at the Hobby-Eberly Telescope for the original discovery of {rho}{sup 1} Cancri e. Usingmore » this large data set we obtain a five-planet Keplerian orbital solution for the system and measure an RV semi-amplitude of K = 6.29 {+-} 0.21 m s{sup -1} for {rho}{sup 1} Cnc e and determine a mass of 8.37 {+-} 0.38 M {sub Circled-Plus }. The uncertainty in mass is thus less than 5%. This planet was previously found to transit its parent star, which allowed them to estimate its radius. Combined with the latest radius estimate from Gillon et al., we obtain a mean density of {rho} = 4.50 {+-} 0.20 g cm{sup -3}. The location of {rho}{sup 1} Cnc e in the mass-radius diagram suggests that the planet contains a significant amount of volatiles, possibly a water-rich envelope surrounding a rocky core.« less

Measurement of the Michel parameter {rho} in normal muon decay

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

Tu, X.; Amann, J.F.; Bolton, R.D.

1995-07-10

A new measurement of the Michel parameter {rho} in normal muon decay has been performed using the MEGA positron spectrometer. Over 500 million triggers were recorded and the data are currently being analyzed. The previous result has a precision on the value of {rho}{plus_minus}0.0026. The present experiment expects to improve the precision to {plus_minus}0.0008 or better. The improved result will be a precise test of the standard model of electroweak interactions for a purely leptonic process. It also will provide a better constraint on the {ital W}{sub {ital R}}{minus}{ital W}{sub {ital L}} mixing angle in the left-right symmetric models. {copyright}more » {ital 1995} {ital American} {ital Institute} {ital of} {ital Physics}.« less

Rho GTPases at the crossroad of signaling networks in mammals

PubMed Central

Wojnacki, José; Quassollo, Gonzalo; Marzolo, María-Paz; Cáceres, Alfredo

2014-01-01

Microtubule (MT) organization and dynamics downstream of external cues is crucial for maintaining cellular architecture and the generation of cell asymmetries. In interphase cells RhoA, Rac, and Cdc42, conspicuous members of the family of small Rho GTPases, have major roles in modulating MT stability, and hence polarized cell behaviors. However, MTs are not mere targets of Rho GTPases, but also serve as signaling platforms coupling MT dynamics to Rho GTPase activation in a variety of cellular conditions. In this article, we review some of the key studies describing the reciprocal relationship between small Rho-GTPases and MTs during migration and polarization. PMID:24691223

Demonstration of elevation and localization of Rho-kinase activity in the brain of a rat model of cerebral infarction.

PubMed

Yano, Kazuo; Kawasaki, Koh; Hattori, Tsuyoshi; Tawara, Shunsuke; Toshima, Yoshinori; Ikegaki, Ichiro; Sasaki, Yasuo; Satoh, Shin-ichi; Asano, Toshio; Seto, Minoru

2008-10-10

Evidence that Rho-kinase is involved in cerebral infarction has accumulated. However, it is uncertain whether Rho-kinase is activated in the brain parenchyma in cerebral infarction. To answer this question, we measured Rho-kinase activity in the brain in a rat cerebral infarction model. Sodium laurate was injected into the left internal carotid artery, inducing cerebral infarction in the ipsilateral hemisphere. At 6 h after injection, increase of activating transcription factor 3 (ATF3) and c-Fos was found in the ipsilateral hemisphere, suggesting that neuronal damage occurs. At 0.5, 3, and 6 h after injection of laurate, Rho-kinase activity in extracts of the cerebral hemispheres was measured by an ELISA method. Rho-kinase activity in extracts of the ipsilateral hemisphere was significantly increased compared with that in extracts of the contralateral hemisphere at 3 and 6 h but not 0.5 h after injection of laurate. Next, localization of Rho-kinase activity was evaluated by immunohistochemical analysis in sections of cortex and hippocampus including infarct area 6 h after injection of laurate. Staining for phosphorylation of myosin-binding subunit (phospho-MBS) and myosin light chain (phospho-MLC), substrates of Rho-kinase, was elevated in neuron and blood vessel, respectively, in ipsilateral cerebral sections, compared with those in contralateral cerebral sections. These findings indicate that Rho-kinase is activated in neuronal and vascular cells in a rat cerebral infarction model, and suggest that Rho-kinase could be an important target in the treatment of cerebral infarction.

The RhoU/Wrch1 Rho GTPase gene is a common transcriptional target of both the gp130/STAT3 and Wnt-1 pathways

PubMed Central

SCHIAVONE, Davide; DEWILDE, Sarah; VALLANIA, Francesco; TURKSON, James; CUNTO, Ferdinando DI; POLI, Valeria

2010-01-01

STAT3 (signal transducer and activator of transcription 3) is a transcription factor activated by cytokines, growth factors and oncogenes, whose activity is required for cell survival/proliferation of a wide variety of primary tumours and tumour cell lines. Prominent among its multiple effects on tumour cells is the stimulation of cell migration and metastasis, whose functional mechanisms are however not completely characterized. RhoU/Wrch1 (Wnt-responsive Cdc42 homologue) is an atypical Rho GTPase thought to be constitutively bound to GTP. RhoU was first identified as a Wnt-1-inducible mRNA and subsequently shown to act on the actin cytoskeleton by stimulating filopodia formation and stress fibre dissolution. It was in addition recently shown to localize to focal adhesions and to Src-induced podosomes and enhance cell migration. RhoU overexpression in mammary epithelial cells stimulates quiescent cells to re-enter the cell cycle and morphologically phenocopies Wnt-1-dependent transformation. In the present study we show that Wnt-1-mediated RhoU induction occurs at the transcriptional level. Moreover, we demonstrate that RhoU can also be induced by gp130 cytokines via STAT3, and we identify two functional STAT3-binding sites on the mouse RhoU promoter. RhoU induction by Wnt-1 is independent of β-catenin, but does not involve STAT3. Rather, it is mediated by the Wnt/planar cell polarity pathway through the activation of JNK (c-Jun N-terminal kinase). Both the so-called non-canonical Wnt pathway and STAT3 are therefore able to induce RhoU, which in turn may be involved in mediating their effects on cell migration. PMID:19397496

Brain distribution and molecular cloning of the bovine GABA rho1 receptor.

PubMed

Rosas-Arellano, Abraham; Ochoa-de la Paz, Lenin David; Miledi, Ricardo; Martínez-Torres, Ataúlfo

2007-03-01

GABA(C) receptors were originally found in the mammalian retina and recent evidence shows that they are also expressed in several areas of the brain, including caudate nucleus, brain stem, pons and corpus callosum. In this study, plasma membranes from the caudate nucleus were microinjected into X. laevis oocytes. This led the oocyte plasma membrane to incorporate functional bicuculline-resistant, Cl(-) conducting bovine GABA receptors, similar to those of the retina. Immunolocalization of the GABA rho1 subunit revealed its expression in bovine neurons in the head of the caudate as well as in the olive, cuneiform and reticular nuclei of the brain stem. The same antibodies failed to show expression in the callosum and pons, where the GABA rho1 mRNA was previously detected. The cloned GABA rho1 sequence predicts a protein with 473 amino acids and 74-93% similarity to other GABA rho1 subunits. Oocytes injected with the cDNA express a non-desensitizing, homomeric receptor with a GABA EC(50)=6.0 microM and a Hill coefficient of 1.8. The results confirm the presence of GABA(C) receptor mRNAs in several areas of the mammalian brain and show that some of these areas express functional GABA rho1 receptors that have the classic GABA(C) receptor characteristics.

Scalar resonances in a unitary {pi}{pi} S-wave model for D{sup +}{yields}{pi}{sup +}{pi}{sup -}{pi}{sup +}

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

Boito, D. R.; Instituto de Fisica, Universidade de Sao Paulo, C.P. 66318, 05315-970, Sao Paulo, SP; Dedonder, J.-P.

We propose a model for D{sup +}{yields}{pi}{sup +}{pi}{sup -}{pi}{sup +} decays following experimental results which indicate that the two-pion interaction in the S wave is dominated by the scalar resonances f{sub 0}(600)/{sigma} and f{sub 0}(980). The weak decay amplitude for D{sup +}{yields}R{pi}{sup +}, where R is a resonance that subsequently decays into {pi}{sup +}{pi}{sup -}, is constructed in a factorization approach. In the S wave, we implement the strong decay R{yields}{pi}{sup +}{pi}{sup -} by means of a scalar form factor. This provides a unitary description of the pion-pion interaction in the entire kinematically allowed mass range m{sub {pi}}{sub {pi}}{sup 2}more » from threshold to about 3 GeV{sup 2}. In order to reproduce the experimental Dalitz plot for D{sup +}{yields}{pi}{sup +}{pi}{sup -}{pi}{sup +}, we include contributions beyond the S wave. For the P wave, dominated by the {rho}(770){sup 0}, we use a Breit-Wigner description. Higher waves are accounted for by using the usual isobar prescription for the f{sub 2}(1270) and {rho}(1450){sup 0}. The major achievement is a good reproduction of the experimental m{sub {pi}}{sub {pi}}{sup 2} distribution, and of the partial as well as the total D{sup +}{yields}{pi}{sup +}{pi}{sup -}{pi}{sup +} branching ratios. Our values are generally smaller than the experimental ones. We discuss this shortcoming and, as a by-product, we predict a value for the poorly known D{yields}{sigma} transition form factor at q{sup 2}=m{sub {pi}}{sup 2}.« less

Observation of Bs production at the Y(5S) resonance.

PubMed

Bonvicini, G; Cinabro, D; Dubrovin, M; Lincoln, A; Bornheim, A; Pappas, S P; Weinstein, A J; Asner, D M; Edwards, K W; Briere, R A; Chen, G P; Chen, J; Ferguson, T; Tatishvili, G; Vogel, H; Watkins, M E; Rosner, J L; Adam, N E; Alexander, J P; Berkelman, K; Cassel, D G; Crede, V; Duboscq, J E; Ecklund, K M; Ehrlich, R; Fields, L; Gibbons, L; Gittelman, B; Gray, R; Gray, S W; Hartill, D L; Heltsley, B K; Hertz, D; Jones, C D; Kandaswamy, J; Kreinick, D L; Kuznetsov, V E; Mahlke-Krüger, H; Meyer, T O; Onyisi, P U E; Patterson, J R; Peterson, D; Phillips, E A; Pivarski, J; Riley, D; Ryd, A; Sadoff, A J; Schwarthoff, H; Shi, X; Shepherd, M R; Stroiney, S; Sun, W M; Urner, D; Wilksen, T; Weaver, K M; Weinberger, M; Athar, S B; Avery, P; Breva-Newell, L; Patel, R; Potlia, V; Stoeck, H; Yelton, J; Rubin, P; Cawlfield, C; Eisenstein, B I; Gollin, G D; Karliner, I; Kim, D; Lowrey, N; Naik, P; Sedlack, C; Selen, M; White, E J; Williams, J; Wiss, J; Besson, D; Pedlar, T K; Cronin-Hennessy, D; Gao, K Y; Gong, D T; Hietala, J; Kubota, Y; Klein, T; Lang, B W; Li, S Z; Poling, R; Scott, A W; Smith, A; Dobbs, S; Metreveli, Z; Seth, K K; Tomaradze, A; Zweber, P; Ernst, J; Arms, K; Severini, H; Dytman, S A; Love, W; Mehrabyan, S; Mueller, J A; Savinov, V; Li, Z; Lopez, A; Mendez, H; Ramirez, J; Huang, G S; Miller, D H; Pavlunin, V; Sanghi, B; Shipsey, I P J; Adams, G S; Anderson, M; Cummings, J P; Danko, I; Napolitano, J; He, Q; Muramatsu, H; Park, C S; Thorndike, E H; Coan, T E; Gao, Y S; Liu, F; Maravin, Y; Artuso, M; Boulahouache, C; Blusk, S; Butt, J; Dorjkhaidav, O; Li, J; Menaa, N; Mountain, R; Nandakumar, R; Randrianarivony, K; Redjimi, R; Sia, R; Skwarnicki, T; Stone, S; Wang, J C; Zhang, K; Csorna, S E

2006-01-20

Using the CLEO detector at the Cornell Electron Storage Ring, we have observed the Bs meson in e+e- annihilation at the Y(5S) resonance. We find 14 candidates consistent with Bs decays into final states with a J/psi or a Ds(*)- . The probability that we have observed a background fluctuation is less than 8 x 10(-10) . We have established that at the energy of the Y(5S) resonance Bs production proceeds predominantly through the creation of Bs*Bs* pairs. We find sigma(e+e- --> Bs*Bs*) = [0.11(-0.03))(+0.04)(stat) +/- 0.02(syst)]nb , and set the following limits: sigma(e+e- --> BsBs)/ sigma(e+ e- --> Bs*Bs*) <0.16 and [sigma(e+e- --> BsBs*) + sigma(e+e- --> Bs*Bs)]/sigma(e+e- -->Bs*Bs*) < 0.16 (90% C.L.). The mass of the Bs* meson is measured to be M(Bs*) = [5.414+/- 0.001(stat) +/- 0.003(syst)] GeV/c2 .

Control of T lymphocyte morphology by the GTPase Rho

NASA Technical Reports Server (NTRS)

Woodside, Darren G.; Wooten, David K.; Teague, T. Kent; Miyamoto, Yuko J.; Caudell, Eva G.; Udagawa, Taturo; Andruss, Bernard F.; McIntyre, Bradley W.

2003-01-01

BACKGROUND: Rho family GTPase regulation of the actin cytoskeleton governs a variety of cell responses. In this report, we have analyzed the role of the GTPase Rho in maintenance of the T lymphocyte actin cytoskeleton. RESULTS: Inactivation of the GTPase Rho in the human T lymphocytic cell line HPB-ALL does not inhibit constitutively high adhesion to the integrin beta1 substrate fibronectin. It did however result in the aberrant extension of finger-like dendritic processes on the substrates VCAM-1, Fn, and mAb specific to beta1 integrins. Time-lapse video microscopy demonstrated that C3 induced extensions were primarily the result of an altered pseudopod elongation rather than retraction. Once the stellate pseudopodia extended, none retracted, and cells became completely immobile. Filipodial structures were absent and the dendritic-like processes in C3 treated cells were rich in filamentous actin. Immunolocalization of RhoA in untreated HPB-ALL cells spreading on fibronectin demonstrated a diffuse staining pattern within the pseudopodia. In C3 treated cells, clusters of RhoA were pronounced and localized within the altered extensions. CONCLUSIONS: GTPase Rho is actively involved in the regulation of T lymphocyte morphology and motility.

The therapeutic effects of Rho-ROCK inhibitors on CNS disorders

PubMed Central

Kubo, Takekazu; Yamaguchi, Atsushi; Iwata, Nobuyoshi; Yamashita, Toshihide

2008-01-01

Rho-kinase (ROCK) is a serine/threonine kinase and one of the major downstream effectors of the small GTPase Rho. The Rho-ROCK pathway is involved in many aspects of neuronal functions including neurite outgrowth and retraction. The Rho-ROCK pathway becomes an attractive target for the development of drugs for treating central nervous system (CNS) disorders, since it has been recently revealed that this pathway is closely related to the pathogenesis of several CNS disorders such as spinal cord injuries, stroke, and Alzheimer’s disease (AD). In the adult CNS, injured axons regenerate poorly due to the presence of myelin-associated axonal growth inhibitors such as myelin-associated glycoprotein (MAG), Nogo, oligodendrocyte-myelin glycoprotein (OMgp), and the recently identified repulsive guidance molecule (RGM). The effects of these inhibitors are reversed by blockade of the Rho-ROCK pathway in vitro, and the inhibition of this pathway promotes axonal regeneration and functional recovery in the injured CNS in vivo. In addition, the therapeutic effects of the Rho-ROCK inhibitors have been demonstrated in animal models of stroke. In this review, we summarize the involvement of the Rho-ROCK pathway in CNS disorders such as spinal cord injuries, stroke, and AD and also discuss the potential of Rho-ROCK inhibitors in the treatment of human CNS disorders. PMID:18827856

A multivariate prediction model for Rho-dependent termination of transcription.

PubMed

Nadiras, Cédric; Eveno, Eric; Schwartz, Annie; Figueroa-Bossi, Nara; Boudvillain, Marc

2018-06-21

Bacterial transcription termination proceeds via two main mechanisms triggered either by simple, well-conserved (intrinsic) nucleic acid motifs or by the motor protein Rho. Although bacterial genomes can harbor hundreds of termination signals of either type, only intrinsic terminators are reliably predicted. Computational tools to detect the more complex and diversiform Rho-dependent terminators are lacking. To tackle this issue, we devised a prediction method based on Orthogonal Projections to Latent Structures Discriminant Analysis [OPLS-DA] of a large set of in vitro termination data. Using previously uncharacterized genomic sequences for biochemical evaluation and OPLS-DA, we identified new Rho-dependent signals and quantitative sequence descriptors with significant predictive value. Most relevant descriptors specify features of transcript C>G skewness, secondary structure, and richness in regularly-spaced 5'CC/UC dinucleotides that are consistent with known principles for Rho-RNA interaction. Descriptors collectively warrant OPLS-DA predictions of Rho-dependent termination with a ∼85% success rate. Scanning of the Escherichia coli genome with the OPLS-DA model identifies significantly more termination-competent regions than anticipated from transcriptomics and predicts that regions intrinsically refractory to Rho are primarily located in open reading frames. Altogether, this work delineates features important for Rho activity and describes the first method able to predict Rho-dependent terminators in bacterial genomes.

Nature of extracellular signal that triggers RhoA/ROCK activation for the basal internal anal sphincter tone in humans

PubMed Central

Singh, Jagmohan; Kumar, Sumit; Phillips, Benjamin

2015-01-01

The extracellular signal that triggers activation of rho-associated kinase (RhoA/ROCK), the major molecular determinant of basal internal anal sphincter (IAS) smooth muscle tone, is not known. Using human IAS tissues, we identified the presence of the biosynthetic machineries for angiotensin II (ANG II), thromboxane A2 (TXA2), and prostaglandin F2α (PGF2α). These end products of the renin-angiotensin system (RAS) (ANG II) and arachidonic acid (TXA2 and PGF2α) pathways and their effects in human IAS vs. rectal smooth muscle (RSM) were studied. A multipronged approach utilizing immunocytochemistry, Western blot analyses, and force measurements was implemented. Additionally, in a systematic analysis of the effects of respective inhibitors along different steps of biosynthesis and those of antagonists, their end products were evaluated either individually or in combination. To further describe the molecular mechanism for the IAS tone via these pathways, we monitored RhoA/ROCK activation and its signal transduction cascade. Data showed characteristically higher expression of biosynthetic machineries of RAS and AA pathways in the IAS compared with the RSM. Additionally, specific inhibition of the arachidonic acid (AA) pathway caused ∼80% decrease in the IAS tone, whereas that of RAS lead to ∼20% decrease. Signal transduction studies revealed that the end products of both AA and RAS pathways cause increase in the IAS tone via activation of RhoA/ROCK. Both AA and RAS (via the release of their end products TXA2, PGF2α, and ANG II, respectively), provide extracellular signals which activate RhoA/ROCK for the maintenance of the basal tone in human IAS. PMID:25882611

Inhibition of Rho Is Required for cAMP-induced Melanoma Cell Differentiation

PubMed Central

Buscà, Roser; Bertolotto, Corine; Abbe, Patricia; Englaro, Walter; Ishizaki, Toshimasa; Narumiya, Shuh; Boquet, Patrice; Ortonne, Jean-Paul; Ballotti, Robert

1998-01-01

Up-regulation of the cAMP pathway by forskolin or α-melanocyte stimulating hormone induces melanocyte and melanoma cell differentiation characterized by stimulation of melanin synthesis and dendrite development. Here we show that forskolin-induced dendricity is associated to a disassembly of actin stress fibers. Since Rho controls actin organization, we studied the role of this guanosine triphosphate (GTP)-binding protein in cAMP-induced dendrite formation. Clostridium botulinum C3 exotransferase, which inhibits Rho, mimicked the effect of forskolin in promoting dendricity and stress fiber disruption, while the Escherichia coli toxin cytotoxic necrotizing factor-1 (CNF-1), which activates Rho and the expression of a constitutively active Rho mutant, blocked forskolin-induced dendrite outgrowth. In addition, overexpression of a constitutively active form of the Rho target p160 Rho-kinase (P160ROCK) prevented the dendritogenic effects of cAMP. Our results suggest that inhibition of Rho and of its target p160ROCK are required events for cAMP-induced dendrite outgrowth in B16 cells. Furthermore, we present evidence that Rho is involved in the regulation of melanogenesis. Indeed, Rho inactivation enhanced the cAMP stimulation of tyrosinase gene transcription and protein expression, while Rho constitutive activation impaired these cAMP-induced effects. This reveals that, in addition to controlling dendricity, Rho also participates in the regulation of melanin synthesis by cAMP. PMID:9614180

Evidence of N*(1535) resonance contribution in the pn{yields}d{phi} reaction

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

Cao Xu; Theoretical Physics Center for Sciences Facilities, Chinese Academy of Sciences, Beijing 100049; Graduate University of Chinese Academy of Sciences, Beijing 100049

2009-08-15

The N*(1535) resonance contributions to the pn{yields}d{phi} reaction are evaluated in an effective Lagrangian model. The {pi}-, {eta}-, and {rho}-meson exchange are considered. It is shown that the contributions from {pi}- and {rho}-meson exchange are dominant, while the contribution from {eta}-meson exchange is negligibly small. Our theoretical results reproduce the experimental data of both total cross section and angular distribution well. This is more evidence that the N*(1535) resonance has a large ss component leading to a large coupling to N{phi}, which may be the real origin of the Okubo-Zweig-Iizuka rule violation in the {pi}N and pN reactions.

Targeting the RhoA-ROCK Pathway to Reverse T Cell Dysfunction in SLE

PubMed Central

Rozo, Cristina; Chinenov, Yurii; Maharaj, Reena Khianey; Gupta, Sanjay; Leuenberger, Laura; Kirou, Kyriakos A.; Bykerk, Vivian P.; Goodman, Susan M.; Salmon, Jane E.; Pernis, Alessandra B.

2018-01-01

Objectives Deregulated production of IL-17 and IL-21 contributes to the pathogenesis of autoimmune disorders like SLE and RA. Production of IL-17 and IL-21 can be regulated by ROCK2, one of the two Rho kinases. Increased ROCK activation was previously observed in an SLE cohort. Here, we evaluated ROCK activity in a new SLE cohort, an RA cohort, and assessed the ability of distinct inhibitors of the ROCK pathway to suppress production of IL-17 and IL-21 by SLE T cells or human Th17 cells. Methods ROCK activity in PBMCs from 29 SLE patients, 31 RA patients, and 28 healthy controls was determined by ELISA. SLE T cells or in vitro-differentiated Th17 cells were treated with Y27632 (a pan-ROCK inhibitor), KD025 (a selective ROCK2 inhibitor), or simvastatin (which inhibits RhoA, a major ROCK activator). ROCK activity, IL-17, and IL-21 production were assessed. The transcriptional profile altered by ROCK inhibitors was evaluated by NanoString technology. Results ROCK activity levels were significantly higher in SLE and RA patients than healthy controls. Th17 cells exhibited high ROCK activity that was inhibited by Y276327, KD025, or simvastatin; each also decreased IL-17 and IL-21 production by purified SLE T cells or Th17 cells. Immune profiling revealed both overlapping and distinct effects of the different ROCK inhibitors. Conclusions ROCK activity is elevated in PBMCs from SLE and RA patients. Production of IL-17 and IL-21 by SLE T cells or Th17 cells can furthermore be inhibited by targeting the RhoA-ROCK pathway via both non-selective and selective approaches. PMID:28283529

RhoA mediates the expression of acidic extracellular pH-induced matrix metalloproteinase-9 mRNA through phospholipase D1 in mouse metastatic B16-BL6 melanoma cells.

PubMed

Maeda, Toyonobu; Yuzawa, Satoshi; Suzuki, Atsuko; Baba, Yuh; Nishimura, Yukio; Kato, Yasumasa

2016-03-01

Solid tumors are characterized by acidic extracellular pH (pHe). The present study examined the contribution of small GTP-binding proteins to phospholipase D (PLD) activation of acidic pHe-induced matrix metalloproteinase-9 (MMP-9) production. Acidic pHe-induced MMP-9 production was reduced by C3 exoenzyme, which inhibits the Rho family of GTPases; cytochalasin D, which inhibits actin reorganization; and simvastatin, which inhibits geranylgeranylation of Rho. Small interfering RNA (siRNA) against RhoA, but not against Rac1 or Cdc42, significantly inhibited acidic pHe induction of MMP-9. Pull-down assays showed that acidic pHe increased the activated form of RhoA. Forced expression of constitutively active RhoA induced MMP-9 production, even at neutral pHe. RhoA siRNA also reduced acidic pHe induced PLD activity. Specific inhibition of PLD1 and Pld1 gene knockout significantly reduced acidic pHe-induced MMP-9 expression. In contrast, PLD2 inhibition or knockout had no effect on MMP-9 expression. These findings suggested that RhoA-PLD1 signaling is involved in acidic pHe induction of MMP-9.

Rho-associated kinase is a therapeutic target in neuroblastoma.

PubMed

Dyberg, Cecilia; Fransson, Susanne; Andonova, Teodora; Sveinbjörnsson, Baldur; Lännerholm-Palm, Jessika; Olsen, Thale K; Forsberg, David; Herlenius, Eric; Martinsson, Tommy; Brodin, Bertha; Kogner, Per; Johnsen, John Inge; Wickström, Malin

2017-08-08

Neuroblastoma is a peripheral neural system tumor that originates from the neural crest and is the most common and deadly tumor of infancy. Here we show that neuroblastoma harbors frequent mutations of genes controlling the Rac/Rho signaling cascade important for proper migration and differentiation of neural crest cells during neuritogenesis. RhoA is activated in tumors from neuroblastoma patients, and elevated expression of Rho-associated kinase (ROCK)2 is associated with poor patient survival. Pharmacological or genetic inhibition of ROCK1 and 2, key molecules in Rho signaling, resulted in neuroblastoma cell differentiation and inhibition of neuroblastoma cell growth, migration, and invasion. Molecularly, ROCK inhibition induced glycogen synthase kinase 3β-dependent phosphorylation and degradation of MYCN protein. Small-molecule inhibition of ROCK suppressed MYCN -driven neuroblastoma growth in TH- MYCN homozygous transgenic mice and MYCN gene-amplified neuroblastoma xenograft growth in nude mice. Interference with Rho/Rac signaling might offer therapeutic perspectives for high-risk neuroblastoma.

Rho-associated kinase is a therapeutic target in neuroblastoma

PubMed Central

Dyberg, Cecilia; Fransson, Susanne; Andonova, Teodora; Sveinbjörnsson, Baldur; Lännerholm-Palm, Jessika; Olsen, Thale K.; Martinsson, Tommy; Brodin, Bertha; Kogner, Per; Johnsen, John Inge

2017-01-01

Neuroblastoma is a peripheral neural system tumor that originates from the neural crest and is the most common and deadly tumor of infancy. Here we show that neuroblastoma harbors frequent mutations of genes controlling the Rac/Rho signaling cascade important for proper migration and differentiation of neural crest cells during neuritogenesis. RhoA is activated in tumors from neuroblastoma patients, and elevated expression of Rho-associated kinase (ROCK)2 is associated with poor patient survival. Pharmacological or genetic inhibition of ROCK1 and 2, key molecules in Rho signaling, resulted in neuroblastoma cell differentiation and inhibition of neuroblastoma cell growth, migration, and invasion. Molecularly, ROCK inhibition induced glycogen synthase kinase 3β-dependent phosphorylation and degradation of MYCN protein. Small-molecule inhibition of ROCK suppressed MYCN-driven neuroblastoma growth in TH-MYCN homozygous transgenic mice and MYCN gene-amplified neuroblastoma xenograft growth in nude mice. Interference with Rho/Rac signaling might offer therapeutic perspectives for high-risk neuroblastoma. PMID:28739902

Scalar resonances in a unitary {pi}{pi} S-wave model for D{sup +} {r_arrow} {pi}{sup+}{pi}{sup-}{pi}{sup+}.

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

Boito, D. R.; Dedonder, J.-P.; El-Bennich, B.

We propose a model for D{sup +} {yields} {pi}{sup +}{pi}{sup -}{pi}{sup +} decays following experimental results which indicate that the two-pion interaction in the S wave is dominated by the scalar resonances f{sub 0}(600)/{sigma} and f{sub 0}(980). The weak decay amplitude for D{sup +} {yields} R{pi}{sup +}, where R is a resonance that subsequently decays into {pi}{sup +}{pi}{sup -}, is constructed in a factorization approach. In the S wave, we implement the strong decay R {yields} {pi}{sup +}{pi}{sup -} by means of a scalar form factor. This provides a unitary description of the pion-pion interaction in the entire kinematically allowedmore » mass range m{sub {pi}{pi}}{sup 2} from threshold to about 3 GeV{sup 2}. In order to reproduce the experimental Dalitz plot for D{sup +} {yields} {pi}{sup +}{pi}{sup -}{pi}{sup +}, we include contributions beyond the S wave. For the P wave, dominated by the {rho}(770){sup 0}, we use a Breit-Wigner description. Higher waves are accounted for by using the usual isobar prescription for the f{sub 2}(1270) and {rho}(1450){sup 0}. The major achievement is a good reproduction of the experimental m{sub {pi}{pi}}{sup 2} distribution, and of the partial as well as the total D{sup +} {yields} {pi}{sup +}{pi}{sup -}{pi}{sup +} branching ratios. Our values are generally smaller than the experimental ones. We discuss this shortcoming and, as a by-product, we predict a value for the poorly known D {yields} {sigma} transition form factor at q{sup 2} = m{sub {pi}}{sup 2}.« less

Analysis of a minimal Rho-GTPase circuit regulating cell shape

NASA Astrophysics Data System (ADS)

Holmes, William R.; Edelstein-Keshet, Leah

2016-08-01

Networks of Rho-family GTPases regulate eukaryotic cell polarization and motility by controlling assembly and contraction of the cytoskeleton. The mutually inhibitory Rac-Rho circuit is emerging as a central, regulatory hub that can affect the shape and motility phenotype of eukaryotic cells. Recent experimental manipulation of the amounts of Rac and Rho or their regulators (guanine nucleotide-exchange factors, GTPase-activating proteins, guanine nucleotide dissociation inhibitors) have been shown to bias the prevalence of these different states and promote transitions between them. Here we show that part of this data can be understood in terms of inherent Rac-Rho mutually inhibitory dynamics. We analyze a spatio-temporal mathematical model of Rac-Rho dynamics to produce a detailed set of predictions of how parameters such as GTPase rates of activation and total amounts affect cell decisions (such as Rho-dominated contraction, Rac-dominated spreading, and spatially segregated Rac-Rho polarization). We find that in some parameter regimes, a cell can take on any of these three fates depending on its environment or stimuli. We also predict how experimental manipulations (corresponding to parameter variations) can affect cell shapes observed. Our methods are based on local perturbation analysis (a kind of nonlinear stability analysis), and an approximation of nonlinear feedback by sharp switches. We compare the Rac-Rho model to an even simpler single-GTPase (‘wave-pinning’) model and demonstrate that the overall behavior is inherent to GTPase properties, rather than stemming solely from network topology.

Effect of Rho family GTP-binding proteins on Amoeba proteus.

PubMed

Kłopocka, W; Redowicz, M J

2003-03-01

While there is a number of studies on the effects of Rho GTPases on the actin-based cytoskeleton in higher eukaryotes, studies in protozoans are rather limited. The problem seems to be intriguing since the structure of protozoan cytoskeletons is distinct from most vertebrate cells. By blocking endogenous Rho family proteins of highly motile Amoeba proteus with C3 transferase and antibodies against human RhoA and Rac1, we tried to assess the in vivo role of these proteins in amoebae. In migrating amoebae, both proteins are concentrated in the cortical layer and seem to colocalize with filamentous actin. Endogenous Rac1, but not RhoA, is accumulated in the perinuclear cytoskeleton. Blocking Rac- or Rho-like proteins caused distinct and irreversible changes in the locomotive shape of the examined amoebae and significant inhibition of their migration. Amoebae microinjected with anti-Rac1 antibodies were contracted, shortened, and developed only few wide pseudopodia. More pronounced changes were observed in cells treated with anti-RhoA antibodies. They exhibited an atypical locomotion not leading to their effective displacement. After treatment with 50 microg of C3 transferase per ml, cells rapidly contracted and almost completely rounded up, became refractile with the granules beaten into a dense mass, detached from the surface and died. Ten times lower concentration of the enzyme caused similar changes as the inhibition of endogenous RhoA-like protein. These results indicate that Rho family-based regulation plays a key role in amoebic migration.

Centralspindlin and α-catenin regulate Rho signalling at the epithelial zonula adherens

PubMed Central

Priya, Rashmi; Verma, Suzie; Kovacs, Eva M.; Jiang, Kai; Brown, Nicholas H.; Akhmanova, Anna; Stehbens, Samantha J.; Yap, Alpha S.

2014-01-01

Summary The biological impact of Rho depends critically on the precise subcellular localization of its active, GTP-loaded form. The spatio-temporal balance between molecules that promote nucleotide exchange or GTP hydrolysis can potentially determine the sites of Rho signalling. But how these activities may be coordinated is poorly understood. We now report a molecular pathway that achieves exactly this coordination at the epithelial zonula adherens. We identify an extramitotic activity of the centralspindlin complex, better understood as a cytokinetic regulator, which localises to the zonula adherens during interphase by interacting with the cadherin-associated protein, α-catenin. Centralspindlin recruits the Rho GEF, Ect2, to the zonula adherens to activate Rho and support junctional integrity through myosin IIA. Centralspindlin also inhibits the junctional localisation of p190RhoGAP B, which can inactivate Rho. Thus, a conserved molecular ensemble that governs Rho activation during cytokinesis is utilized in interphase cells to control the Rho GTPase cycle at the zonula adherens. PMID:22750944

Transcription termination factor Rho: a hub linking diverse physiological processes in bacteria.

PubMed

Grylak-Mielnicka, Aleksandra; Bidnenko, Vladimir; Bardowski, Jacek; Bidnenko, Elena

2016-03-01

Factor-dependent termination of transcription in bacteria relies on the activity of a specific RNA helicase, the termination factor Rho. Rho is nearly ubiquitous in bacteria, but the extent to which its physiological functions are conserved throughout the different phyla remains unknown. Most of our current knowledge concerning the mechanism of Rho's activity and its physiological roles comes from the model micro-organism Escherichia coli, where Rho is essential and involved in the control of several important biological processes. However, the rather comprehensive knowledge about the general mechanisms of action and activities of Rho based on the E. coli paradigm cannot be directly extrapolated to other bacteria. Recent studies performed in different species favour the view that Rho-dependent termination plays a significant role even in bacteria where Rho is not essential. Here, we summarize the current state of the ever-increasing knowledge about the various aspects of the physiological functions of Rho, such as limitation of deleterious foreign DNA expression, control of gene expression, suppression of pervasive transcription, prevention of R-loops and maintenance of chromosome integrity, focusing on similarities and differences of the activities of Rho in various bacterial species.

The activation of p38 MAPK primarily contributes to UV-induced RhoB expression by recruiting the c-Jun and p300 to the distal CCAAT box of the RhoB promoter

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

Ahn, Jiwon; Department of Microbiology, Chungnam National University, Daejeon 305-764; Choi, Jeong-Hae

2011-06-03

Highlights: {yields} Regulation of transcriptional activation of RhoB is still unclear. {yields} We examine the effect of p38 MAPK inhibition, and c-Jun and RhoB depletion on UV-induced RhoB expression and apoptosis. {yields} We identify the regions of RhoB promoter necessary to confer UV responsiveness using pRhoB-luciferase reporter assays. {yields} c-Jun, ATF2 and p300 are dominantly associated with NF-Y on the distal CCAAT box. {yields} The activation of p38 MAPK primarily contribute to UV-induced RhoB expression by recruiting the c-Jun and p300 proteins on distal CCAAT box of RhoB promoter. -- Abstract: The Ras-related small GTP-binding protein RhoB is rapidly inducedmore » in response to genotoxic stresses caused by ionizing radiation. It is known that UV-induced RhoB expression results from the binding of activating transcription factor 2 (ATF2) via NF-Y to the inverted CCAAT box (-23) of the RhoB promoter. Here, we show that the association of c-Jun with the distal CCAAT box (-72) is primarily involved in UV-induced RhoB expression and p38 MAPK regulated RhoB induction through the distal CCAAT box. UV-induced RhoB expression and apoptosis were markedly attenuated by pretreatment with the p38 MAPK inhibitor. siRNA knockdown of RhoB, ATF2 and c-Jun resulted in decreased RhoB expression and eventually restored the growth of UV-irradiated Jurkat cells. In the reporter assay using luciferase under the RhoB promoter, inhibition of RhoB promoter activity by the p38 inhibitor and knockdown of c-Jun using siRNA occurred through the distal CCAAT box. Immunoprecipitation and DNA affinity protein binding assays revealed the association of c-Jun and p300 via NF-YA and the dissociation of histone deacetylase 1 (HDAC1) via c-Jun recruitment to the CCAAT boxes of the RhoB promoter. These results suggest that the activation of p38 MAPK primarily contributes to UV-induced RhoB expression by recruiting the c-Jun and p300 proteins to the distal CCAAT box of the RhoB promoter

Unique Structural and Nucleotide Exchange Features of the Rho1 GTPase of Entamoeba histolytica

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

Bosch, Dustin E.; Wittchen, Erika S.; Qiu, Connie

The single-celled human parasite Entamoeba histolytica possesses a dynamic actin cytoskeleton vital for its intestinal and systemic pathogenicity. The E. histolytica genome encodes several Rho family GTPases known to regulate cytoskeletal dynamics. EhRho1, the first family member identified, was reported to be insensitive to the Rho GTPase-specific Clostridium botulinum C3 exoenzyme, raising the possibility that it may be a misclassified Ras family member. Here, we report the crystal structures of EhRho1 in both active and inactive states. EhRho1 is activated by a conserved switch mechanism, but diverges from mammalian Rho GTPases in lacking a signature Rho insert helix. EhRho1 engagesmore » a homolog of mDia, EhFormin1, suggesting a role in mediating serum-stimulated actin reorganization and microtubule formation during mitosis. EhRho1, but not a constitutively active mutant, interacts with a newly identified EhRhoGDI in a prenylation-dependent manner. Furthermore, constitutively active EhRho1 induces actin stress fiber formation in mammalian fibroblasts, thereby identifying it as a functional Rho family GTPase. EhRho1 exhibits a fast rate of nucleotide exchange relative to mammalian Rho GTPases due to a distinctive switch one isoleucine residue reminiscent of the constitutively active F28L mutation in human Cdc42, which for the latter protein, is sufficient for cellular transformation. Nonconserved, nucleotide-interacting residues within EhRho1, revealed by the crystal structure models, were observed to contribute a moderating influence on fast spontaneous nucleotide exchange. Collectively, these observations indicate that EhRho1 is a bona fide member of the Rho GTPase family, albeit with unique structural and functional aspects compared with mammalian Rho GTPases.« less

Neural activation-based sexual orientation and its correlation with free testosterone level in postoperative female-to-male transsexuals: preliminary study with 3.0-T fMRI.

PubMed

Kim, Gwang-Won; Kim, Seok-Kwun; Jeong, Gwang-Woo

2016-03-01

The purpose of this study was to evaluate the brain activation pattern associated with sexual orientation and its correlation with the level of the free testosterone (free T) in postoperative female-to-male (FtM) transsexuals using a 3.0-Tesla functional magnetic resonance imaging (fMRI). Eleven postoperative FtM transsexuals with sex reassignment surgery underwent fMRI on a 3.0-T MR scanner. Brain activity was measured while viewing erotic male and female nude pictures. The average level of free T in the FtM transsexuals was in the normal range of heterosexual men. The brain areas with predominant activities during viewing female nude pictures in contrast to male pictures included the hippocampus, parahippocampal gyrus, anterior cingulate gyrus, putamen, amygdala, hypothalamus, and insula (p < 0.005). The free T levels were positively correlated with the BOLD signal changes in the parahippocampal gyrus (Spearman's rho = 0.91, p < 0.001), hippocampus (rho = 0.90, p < 0.001), insula (rho = 0.68, p < 0.05), putamen (rho = 0.66, p < 0.05), and amygdala (rho = 0.64, p < 0.05). Compared to FtM transsexuals with deficient level of free T, the FtM transsexuals with normal range of free T showed significantly higher activities in the parahippocampal gyrus, hippocampus, insula, putamen, and amygdala during viewing female nude pictures (p < 0.005). This study revealed the specific brain activation pattern associated with sexual orientation and its correlation with free T in the postoperative FtM transsexuals. These findings are applicable in understanding the neural mechanism on sexual arousal in FtM transsexuals and their sexual orientation in connection with the free T levels.

Electromagnetic Meson Production in the Nucleon Resonance Region

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

Volker Burkert; T.-S. H. Lee

Recent experimental and theoretical advances in investigating electromagnetic meson production reactions in the nucleon resonance region are reviewed. The article gives a description of current experimental facilities with electron and photon beams and presents a unified derivation of most of the phenomenological approaches being used to extract the resonance parameters from the data. The analyses of {pi} and {eta} production data and the resulting transition form factors for the {Delta}(1232)P{sub 33}, N(1535)S{sub 11}, N(1440)P{sub 11}, and N(1520)D{sub 13} resonances are discussed in detail. The status of our understanding of the reactions with production of two pions, kaons, and vector mesonsmore » is also reviewed.« less

Assessment of Rho GTPase signaling during neurite outgrowth.

PubMed

Feltrin, Daniel; Pertz, Olivier

2012-01-01

Rho GTPases are key regulators of the cytoskeleton during the process of neurite outgrowth. Based on overexpression of dominant-positive and negative Rho GTPase constructs, the classic view is that Rac1 and Cdc42 are important for neurite elongation whereas RhoA regulates neurite retraction in response to collapsing agents. However, recent work has suggested a much finer control of spatiotemporal Rho GTPase signaling in this process. Understanding this complexity level necessitates a panel of more sensitive tools than previously used. Here, we discuss a novel assay that enables the biochemical fractionation of the neurite from the soma of differentiating N1E-115 neuronal-like cells. This allows for spatiotemporal characterization of a large number of protein components, interactions, and post-translational modifications using classic biochemical and also proteomics approaches. We also provide protocols for siRNA-mediated knockdown of genes and sensitive assays that allow quantitative analysis of the neurite outgrowth process.

The effect of the Ras homolog gene family (Rho), member A/Rho associated coiled-coil forming protein kinase pathway in atrial fibrosis of type 2 diabetes in rats.

PubMed

Chen, Jinling; Li, Qingqing; Dong, Ruiqing; Gao, Huikuan; Peng, Hui; Wu, Yongquan

2014-09-01

Diabetes mellitus promotes atrial structural remodeling, thereby producing atrial arrhythmogenicity. Atrial arrhythmia can substantially increase the risk of premature death. The aim of this study was to investigate the role of Ras homolog gene family, member A (RhoA)/Rho associated coiled-coil forming protein kinase (ROCK) in atrial fibrosis in diabetic hearts, and the effects of fasudil hydrochloride hydrate on atrial fibrosis. An eight-week-old male Sprague-Dawley rat model of type 2 diabetes was established using a high-fat diet combined with streptozotocin [30 mg/kg, once, intraperitoneal (i.p.)]. Animals were randomly divided into three groups: Control rats, untreated diabetic rats that received vehicle, and treated diabetic rats that received Rho kinase inhibitor fasudil hydrochloride hydrate (10 mg/kg/day, i.p., for 14 weeks). The morphological features of atrial fibrosis were observed using Masson staining. The mRNA expression levels of RhoA, ROCK1, ROCK2, type-I and type-III procollagen were assessed with quantitative polymerase chain reaction. The protein levels of RhoA, ROCK1 and ROCK2 were evaluated using western blot analysis. The atria of untreated diabetic rats showed evident atrial fibrosis as compared to the control rats; the mRNA expression levels of RhoA, ROCK1, ROCK2, type-I and type-III procollagen were upregulated; and the protein levels of RhoA, ROCK1 and ROCK2 were increased. The treatment with fasudil hydrochloride hydrate significantly reduced atrial fibrosis, mRNA levels of RhoA, ROCK1, ROCK2, type-I and type-III procollagen, and the protein levels of RhoA, ROCK1 and ROCK2. The results suggested that RhoA/ROCK was involved in atrial fibrosis, and that fasudil hydrochloride hydrate ameliorates atrial fibrosis through the RhoA/ROCK pathway in rats with type 2 diabetes.

Contribution of Rho-kinase to membrane excitability of murine colonic smooth muscle.

PubMed

Bayguinov, O; Dwyer, L; Kim, H; Marklew, A; Sanders, K M; Koh, S D

2011-06-01

The Rho-kinase pathway regulates agonist-induced contractions in several smooth muscles, including the intestine, urinary bladder and uterus, via dynamic changes in the Ca(2+) sensitivity of the contractile apparatus. However, there is evidence that Rho-kinase also modulates other cellular effectors such as ion channels. We examined the regulation of colonic smooth muscle excitability by Rho-kinase using conventional microelectrode recording, isometric force measurements and patch-clamp techniques. The Rho-kinase inhibitors, Y-27632 and H-1152, decreased nerve-evoked on- and off-contractions elicited at a range of frequencies and durations. The Rho-kinase inhibitors decreased the spontaneous contractions and the responses to carbachol and substance P independently of neuronal inputs, suggesting Y-27632 acts directly on smooth muscle. The Rho-kinase inhibitors significantly reduced the depolarization in response to carbachol, an effect that cannot be due to regulation of Ca(2+) sensitization. Patch-clamp experiments showed that Rho-kinase inhibitors reduce GTPγS-activated non-selective cation currents. The Rho-kinase inhibitors decreased contractions evoked by nerve stimulation, carbachol and substance P. These effects were not solely due to inhibition of the Ca(2+) sensitization pathway, as the Rho-kinase inhibitors also inhibited the non-selective cation conductances activated by excitatory transmitters. Thus, Rho-kinase may regulate smooth muscle excitability mechanisms by regulating non-selective cation channels as well as changing the Ca(2+) sensitivity of the contractile apparatus. © 2011 The Authors. British Journal of Pharmacology © 2011 The British Pharmacological Society.

Targeting the RhoA-ROCK pathway to reverse T-cell dysfunction in SLE.

PubMed

Rozo, Cristina; Chinenov, Yurii; Maharaj, Reena Khianey; Gupta, Sanjay; Leuenberger, Laura; Kirou, Kyriakos A; Bykerk, Vivian P; Goodman, Susan M; Salmon, Jane E; Pernis, Alessandra B

2017-04-01

Deregulated production of interleukin (IL)-17 and IL-21 contributes to the pathogenesis of autoimmune disorders such as systemic lupus erythematosus (SLE) and rheumatoid arthritis (RA). Production of IL-17 and IL-21 can be regulated by ROCK2, one of the two Rho kinases. Increased ROCK activation was previously observed in an SLE cohort. Here, we evaluated ROCK activity in a new SLE cohort, and an RA cohort, and assessed the ability of distinct inhibitors of the ROCK pathway to suppress production of IL-17 and IL-21 by SLE T cells or human Th17 cells. ROCK activity in peripheral blood mononuclear cells (PBMCs) from 29 patients with SLE, 31 patients with RA and 28 healthy controls was determined by ELISA. SLE T cells or in vitro-differentiated Th17 cells were treated with Y27632 (a pan-ROCK inhibitor), KD025 (a selective ROCK2 inhibitor) or simvastatin (which inhibits RhoA, a major ROCK activator). ROCK activity and IL-17 and IL-21 production were assessed. The transcriptional profile altered by ROCK inhibitors was evaluated by NanoString technology. ROCK activity levels were significantly higher in patients with SLE and RA than healthy controls. Th17 cells exhibited high ROCK activity that was inhibited by Y27632, KD025 or simvastatin; each also decreased IL-17 and IL-21 production by purified SLE T cells or Th17 cells. Immune profiling revealed both overlapping and distinct effects of the different ROCK inhibitors. ROCK activity is elevated in PBMCs from patients with SLE and RA. Production of IL-17 and IL-21 by SLE T cells or Th17 cells can furthermore be inhibited by targeting the RhoA-ROCK pathway via both non-selective and selective approaches. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

Activation of G protein-coupled estrogen receptor 1 induces coronary artery relaxation via Epac/Rap1-mediated inhibition of RhoA/Rho kinase pathway in parallel with PKA.

PubMed

Yu, Xuan; Zhang, Qiao; Zhao, Yan; Schwarz, Benjamin J; Stallone, John N; Heaps, Cristine L; Han, Guichun

2017-01-01

Previously, we reported that cAMP/PKA signaling is involved in GPER-mediated coronary relaxation by activating MLCP via inhibition of RhoA pathway. In the current study, we tested the hypothesis that activation of GPER induces coronary artery relaxation via inhibition of RhoA/Rho kinase pathway by cAMP downstream targets, exchange proteins directly activated by cAMP (Epac) as well as PKA. Our results show that Epac inhibitors, brefeldin A (BFA, 50 μM), or ESI-09 (20 μM), or CE3F4 (100 μM), all partially inhibited porcine coronary artery relaxation response to the selective GPER agonist, G-1 (0.3-3 μM); while concurrent administration of BFA and PKI (5 μM), a PKA inhibitor, almost completely blocked the relaxation effect of G-1. The Epac specific agonist, 8-CPT-2Me-cAMP (007, 1-100 μM), induced a concentration-dependent relaxation response. Furthermore, the activity of Ras-related protein 1 (Rap1) was up regulated by G-1 (1 μM) treatment of porcine coronary artery smooth muscle cells (CASMCs). Phosphorylation of vasodilator-stimulated phosphoprotein (p-VASP) was elevated by G-1 (1 μM) treatment, but not by 007 (50 μM); and the effect of G-1 on p-VASP was blocked by PKI, but not by ESI-09, an Epac antagonist. RhoA activity was similarly down regulated by G-1 and 007, whereas ESI-09 restored most of the reduced RhoA activity by G-1 treatment. Furthermore, G-1 decreased PGF2α-induced p-MYPT1, which was partially reversed with either ESI-09 or PKI; whereas, concurrent administration of ESI-09 and PKI totally prevented the inhibitory effect of G-1. The inhibitory effects of G-1 on p- MLC levels in CASMCs were mostly restored by either ESI-09 or PKI. These results demonstrate that activation of GPER induces coronary artery relaxation via concurrent inhibition of RhoA/Rho kinase by Epac/Rap1 and PKA. GPER could be a potential drug target for preventing and treating cardiovascular diseases.

Looking at the bright side of the rho Ophiuchi dark cloud. Far infrared spectrophotometric observations of the rho Oph cloud with the ISO

NASA Astrophysics Data System (ADS)

Liseau, R.; White, G. J.; Larsson, B.; Sidher, S.; Olofsson, G.; Kaas, A.; Nordh, L.; Caux, E.; Lorenzetti, D.; Molinari, S.; Nisini, B.; Sibille, F.

1999-04-01

We present far infrared (45-195 mu m) spectrophotometric observations with the Iso-Lws of the active star forming rho Oph main cloud (L 1688). The [C ii] 158 mu m and [O i] 63 mu m lines were detected at each of the 33 positions observed, whereas the [O i] 145 mu m line was clearly seen toward twelve. The principal observational result is that the [C ii] 158 mu m line fluxes exhibit a clear correlation with projected distance from the dominant stellar source in the field (HD 147889). We interpret this in terms of Pdr-type emission from the surface layers of the rho Ophc. The observed [C ii] 158 mu m/[O i] 63 mu m flux ratios are larger than unity everywhere. A comparison of the [C ii] 158 mu m line emission and the Fir dust continuum fluxes yields estimates of the efficiency at which the gas in the cloud converts stellar to [C ii] 158 mu m photons (chi_ {_C II},>_{ ~ },0.5%). We first develop an empirical model, which provides us with a three dimensional view of the far and bright side of the dark rho Ophc, showing that the cloud surface towards the putative energy source is concave. This model also yields quantitative estimates of the incident flux of ultraviolet radiation (G_0 ~ , \\powten{1} - \\powten{2}) and of the degree of clumpiness/texture of the cloud surface (filling of the 80({') '} beam ~ ,0.2). Subsequently, we use theoretical models of Pdr s to derive the particle density, n(H), and the temperature structures, for T_gas and T_dust, in the surface layers of the rho Ophc. T_gas is relatively low, ~ ,60 K, but higher than T_dust ( ~ ,30 K), and densities are generally found within the interval (1-3) \\powten{4} cm(-3) . These Pdr models are moderately successful in explaining the Lws observations. They correctly predict the [O i] 63 mu m and [C ii] 158 mu m line intensities and the observed absence of any molecular line emission. The models do fail, however, to reproduce the observed small [O i] 63 mu m/[O i] 145 mu m ratios. We examine several possible

Redundancy of primary RNA-binding functions of the bacterial transcription terminator Rho

PubMed Central

Shashni, Rajesh; Qayyum, M. Zuhaib; Vishalini, V.; Dey, Debashish; Sen, Ranjan

2014-01-01

The bacterial transcription terminator, Rho, terminates transcription at half of the operons. According to the classical model derived from in vitro assays on a few terminators, Rho is recruited to the transcription elongation complex (EC) by recognizing specific sites (rut) on the nascent RNA. Here, we explored the mode of in vivo recruitment process of Rho. We show that sequence specific recognition of the rut site, in majority of the Rho-dependent terminators, can be compromised to a great extent without seriously affecting the genome-wide termination function as well as the viability of Escherichia coli. These terminators function optimally only through a NusG-assisted recruitment and activation of Rho. Our data also indicate that at these terminators, Rho-EC-bound NusG interaction facilitates the isomerization of Rho into a translocase-competent form by stabilizing the interactions of mRNA with the secondary RNA binding site, thereby overcoming the defects of the primary RNA binding functions. PMID:25081210

Regulation of endocytic traffic by Rho GTPases.

PubMed Central

Qualmann, Britta; Mellor, Harry

2003-01-01

The members of the Rho subfamily of small GTPases are key regulators of the actin cytoskeleton. However, recent studies have provided evidence for multiple additional roles for these signalling proteins in controlling endocytic traffic. Here we review our current understanding of Rho GTPase action within the endocytic pathway and examine the potential points of convergence with the more established, actin-based functions of these signalling proteins. PMID:12564953

Saponins extracted from by-product of Asparagus officinalis L. suppress tumour cell migration and invasion through targeting Rho GTPase signalling pathway.

PubMed

Wang, Jieqiong; Liu, Yali; Zhao, Jingjing; Zhang, Wen; Pang, Xiufeng

2013-04-01

The inedible bottom part (~30-40%) of asparagus (Asparagus officinalis L.) spears is usually discarded as waste. However, since this by-product has been reported to be rich in many bioactive phytochemicals, it might be utilisable as a supplement in foods or natural drugs for its therapeutic effects. In this study it was identifed that saponins from old stems of asparagus (SSA) exerted potential inhibitory activity on tumour growth and metastasis. SSA suppressed cell viability of breast, colon and pancreatic cancers in a concentration-dependent manner, with half-maximum inhibitory concentrations ranging from 809.42 to 1829.96 µg mL(-1). However, SSA was more functional in blocking cell migration and invasion as compared with its cytotoxic effect, with an effective inhibitory concentration of 400 µg mL(-1). A mechanistic study showed that SSA markedly increased the activities of Cdc42 and Rac1 and decreased the activity of RhoA in cancer cells. SSA inhibits tumour cell motility through modulating the Rho GTPase signalling pathway, suggesting a promising use of SSA as a supplement in healthcare foods and natural drugs for cancer prevention and treatment. © 2012 Society of Chemical Industry.

A structural study of the complex between neuroepithelial cell transforming gene 1 (Net1) and RhoA reveals a potential anticancer drug hot spot.

PubMed

Petit, Alain-Pierre; Garcia-Petit, Christel; Bueren-Calabuig, Juan A; Vuillard, Laurent M; Ferry, Gilles; Boutin, Jean A

2018-06-08

The GTPase RhoA is a major player in many different regulatory pathways. RhoA catalyzes GTP hydrolysis, and its catalysis is accelerated when RhoA forms heterodimers with proteins of the guanine nucleotide exchange factor (GEF) family. Neuroepithelial cell transforming gene 1 (Net1) is a RhoA-interacting GEF implicated in cancer, but the structural features supporting the RhoA/Net1 interaction are unknown. Taking advantage of a simple production and purification process, here we solved the structure of a RhoA/Net1 heterodimer with X-ray crystallography at 2-Å resolution. Using a panel of several techniques, including molecular dynamics simulations, we characterized the RhoA/Net1 interface. Moreover, deploying an extremely simple peptide-based scanning approach, we found that short peptides (penta- to nonapeptides) derived from the protein/protein interaction region of RhoA could disrupt the RhoA/Net1 interaction and thereby diminish the rate of nucleotide exchange. The most inhibitory peptide, EVKHF, spanning residues 102-106 in the RhoA sequence, displayed an IC 50 of ∼100 μm without further modifications. The peptides identified here could be useful in further investigations of the RhoA/Net1 interaction region. We propose that our structural and functional insights might inform chemical approaches for transforming the pentapeptide into an optimized pseudopeptide that antagonizes Net1-mediated RhoA activation with therapeutic anticancer potential. © 2018 by The American Society for Biochemistry and Molecular Biology, Inc.

Ameloblasts require active RhoA to generate normal dental enamel.

PubMed

Xue, Hui; Li, Yong; Everett, Eric T; Ryan, Kathleen; Peng, Li; Porecha, Rakhee; Yan, Yan; Lucchese, Anna M; Kuehl, Melissa A; Pugach, Megan K; Bouchard, Jessica; Gibson, Carolyn W

2013-08-01

RhoA plays a fundamental role in regulation of the actin cytoskeleton, intercellular attachment, and cell proliferation. During amelogenesis, ameloblasts (which produce the enamel proteins) undergo dramatic cytoskeletal changes and the RhoA protein level is up-regulated. Transgenic mice were generated that express a dominant-negative RhoA transgene in ameloblasts using amelogenin gene-regulatory sequences. Transgenic and wild-type (WT) molar tooth germs were incubated with sodium fluoride (NaF) or sodium chloride (NaCl) in organ culture. Filamentous actin (F-actin) stained with phalloidin was elevated significantly in WT ameloblasts treated with NaF compared with WT ameloblasts treated with NaCl or with transgenic ameloblasts treated with NaF, thereby confirming a block in the RhoA/Rho-associated protein kinase (ROCK) pathway in the transgenic mice. Little difference in quantitative fluorescence (an estimation of fluorosis) was observed between WT and transgenic incisors from mice provided with drinking water containing NaF. We subsequently found reduced transgene expression in incisors compared with molars. Transgenic molar teeth had reduced amelogenin, E-cadherin, and Ki67 compared with WT molar teeth. Hypoplastic enamel in transgenic mice correlates with reduced expression of the enamel protein, amelogenin, and E-cadherin and cell proliferation are regulated by RhoA in other tissues. Together these findings reveal deficits in molar ameloblast function when RhoA activity is inhibited. © 2013 Eur J Oral Sci.

LEP precision electroweak measurements from the Z{sup 0} resonance

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

Strom, D.

1997-01-01

Preliminary electroweak measurements from the LEP Collaboration from data taken at the Z{sup 0} resonance are presented. Most of the results presented are based on a total data sample of 12 x 10{sup 6} recorded Z{sup 0} events which included data from the 1993 and 1994 LEP runs. The Z{sup 0} resonance parameters, including hadronic and leptonic cross sections and asymmetries, {tau} polarization and its asymmetry, and heavy-quark asymmetries and partial widths, are evaluated and confronted with the predictions of the Standard Model. This comparison incorporates the constraints provided by the recent determination of the top-quark mass at the Tevatron.more » The Z{sup 0} resonance parameters are found to be in good agreement with the Standard Model prediction using the Tevatron top-quark mass, with the exception of the partial widths for Z{sup 0} decays to pairs of b and c quarks.« less

Reaction. pi. /sup -/p. --> pi. /sup -/. pi. /sup +/. pi. /sup -/p at 8 GeV/c

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

Kitagaki, T.; Tanaka, S.; Yuta, H.

1982-10-01

Results from a high-statistics experiment involving an exposure of the SLAC 82-in. hydrogen bubble chamber to a beam of 8-GeV/c ..pi../sup -/ yielding a final state of ..pi../sup -/..pi../sup +/..pi../sup -/p are presented. Copious production of rho, ..delta../sup + +/, and f is found. Considerable quasi-two-body production in which one particle decays to one of the above resonances is also observed. Some double-resonance production involving baryon and meson resonances is also seen. The production properties of rho, ..delta../sup + +/, and f mesons are well described by a double-Regge model.

An adventitious interaction of filamin A with RhoGDI2(Tyr153Glu)

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

Song, Mia; He, Qianjing; Berk, Benjamin-Andreas

2016-01-15

Filamin A (FLNA) is an actin filament crosslinking protein with multiple intracellular binding partners. Mechanical force exposes cryptic FLNA binding sites for some of these ligands. To identify new force-dependent binding interactions, we used a fusion construct composed of two FLNA domains, one of which was previously identified as containing a force-dependent binding site as a bait in a yeast two-hybrid system and identified the Rho dissociation inhibitor 2 (RhoGDI2) as a potential interacting partner. A RhoGDI2 truncate with 81 N-terminal amino acid residues and a phosphomimetic mutant, RhoGDI(Tyr153Glu) interacted with the FLNA construct. However, neither wild-type or full-length RhoGDI2 phosphorylatedmore » at Y153 interacted with FLNA. Our interpretation of these contradictions is that truncation and/or mutation of RhoGDI2 perturbs its conformation to expose a site that adventitiously binds FLNA and is not a bona–fide interaction. Therefore, previous studies reporting that a RhoGDI(Y153E) mutant suppresses the metastasis of human bladder cancer cells must be reinvestigated in light of artificial interaction of this point mutant with FLNA. - Highlights: • RhoGDI2 is identified as a potential filamin A (FLNA)-binding partner. • Phosphomimetic mutant, RhoGDI2(Tyr153Glu) interacts with FLNA. • RhoGDI2 phosphorylated (Tyr153) by src kinase does not interact with FLNA. • Mutation of Tyr-153 to Glu of RhoGDI2 does not mimic phosphorylation. • RhoGDI2(Tyr153Glu) provokes an adventitious interaction with FLNA.« less

The RhoA/ROCK Pathway Ameliorates Adhesion and Inflammatory Infiltration Induced by AGEs in Glomerular Endothelial Cells.

PubMed

Rao, Jialing; Ye, Zengchun; Tang, Hua; Wang, Cheng; Peng, Hui; Lai, Weiyan; Li, Yin; Huang, Wanbing; Lou, Tanqi

2017-01-05

A recent study demonstrated that advanced glycation end products (AGEs) play a role in monocyte infiltration in mesangial areas in diabetic nephropathy. The Ras homolog gene family, member A Rho kinase (RhoA/ROCK) pathway plays a role in regulating cell migration. We hypothesized that the RhoA/ROCK pathway affects adhesion and inflammation in endothelial cells induced by AGEs. Rat glomerular endothelial cells (rGECs) were cultured with AGEs (80 μg/ml) in vitro. The ROCK inhibitor Y27632 (10 nmol/l) and ROCK1-siRNA were used to inhibit ROCK. We investigated levels of the intercellular adhesion molecule 1 (ICAM-1) and monocyte chemoattractant protein1 (MCP-1) in rGECs. Db/db mice were used as a diabetes model and received Fasudil (10 mg/kg/d, n = 6) via intraperitoneal injection for 12 weeks. We found that AGEs increased the expression of ICAM-1 and MCP-1 in rGECs, and the RhoA/ROCK pathway inhibitor Y27632 depressed the release of adhesion molecules. Moreover, blocking the RhoA/ROCK pathway ameliorated macrophage transfer to the endothelium. Reduced expression of adhesion molecules and amelioration of inflammatory cell infiltration in the glomerulus were observed in db/db mice treated with Fasudil. The RhoA/ROCK pathway plays a role in adhesion molecule expression and inflammatory cell infiltration in glomerular endothelial cells induced by AGEs.

Unusually long-lived pause required for regulation of a Rho-dependent transcription terminator.

PubMed

Hollands, Kerry; Sevostiyanova, Anastasia; Groisman, Eduardo A

2014-05-13

Up to half of all transcription termination events in bacteria rely on the RNA-dependent helicase Rho. However, the nucleic acid sequences that promote Rho-dependent termination remain poorly characterized. Defining the molecular determinants that confer Rho-dependent termination is especially important for understanding how such terminators can be regulated in response to specific signals. Here, we identify an extraordinarily long-lived pause at the site where Rho terminates transcription in the 5'-leader region of the Mg(2+) transporter gene mgtA in Salmonella enterica. We dissect the sequence elements required for prolonged pausing in the mgtA leader and establish that the remarkable longevity of this pause is required for a riboswitch to stimulate Rho-dependent termination in the mgtA leader region in response to Mg(2+) availability. Unlike Rho-dependent terminators described previously, where termination occurs at multiple pause sites, there is a single site of transcription termination directed by Rho in the mgtA leader. Our data suggest that Rho-dependent termination events that are subject to regulation may require elements distinct from those operating at constitutive Rho-dependent terminators.

Unusually long-lived pause required for regulation of a Rho-dependent transcription terminator

PubMed Central

Hollands, Kerry; Sevostiyanova, Anastasia; Groisman, Eduardo A.

2014-01-01

Up to half of all transcription termination events in bacteria rely on the RNA-dependent helicase Rho. However, the nucleic acid sequences that promote Rho-dependent termination remain poorly characterized. Defining the molecular determinants that confer Rho-dependent termination is especially important for understanding how such terminators can be regulated in response to specific signals. Here, we identify an extraordinarily long-lived pause at the site where Rho terminates transcription in the 5′-leader region of the Mg2+ transporter gene mgtA in Salmonella enterica. We dissect the sequence elements required for prolonged pausing in the mgtA leader and establish that the remarkable longevity of this pause is required for a riboswitch to stimulate Rho-dependent termination in the mgtA leader region in response to Mg2+ availability. Unlike Rho-dependent terminators described previously, where termination occurs at multiple pause sites, there is a single site of transcription termination directed by Rho in the mgtA leader. Our data suggest that Rho-dependent termination events that are subject to regulation may require elements distinct from those operating at constitutive Rho-dependent terminators. PMID:24778260

Inclusive ϱ0 production in overlineνμp charged current interactions

NASA Astrophysics Data System (ADS)

Grässler, H.; Lanske, D.; Schulte, R.; Jones, G. T.; Kennedy, B. W.; Middleton, R. P.; O'Neale, S. W.; Böckmann, K.; Gebel, W.; Geich-Gimbel, C.; Hoffmann, E.; Nellen, B.; Saarikko, H.; Klein, H.; Mittendorfer, J.; Morrison, D. R. O.; Schmid, P.; Wachsmuth, H.; Barnham, K. W. J.; Clayton, E. F.; Hamisi, F.; Miller, D. B.; Mobayyen, M. M.; Aderholz, M.; Deck, L.; Schmitz, N.; Wittek, W.; Corrigan, G.; Myatt, G.; Radojicic, D.; Saitta, B.; Wells, J.; Aachen-Birmingham-Bonn-CERN-Imperial College-München (MPI)-Oxford Collaboration

1986-07-01

Inclusive ϱ0 production has been studied in antineutrino-proton charged current interactions, using a sample of 3340 events obtained in BEBC filled with hydrogen and exposed to the CERN wideband antineutrino beam. An average multiplicity of 0.11 ± 0.02 ϱ0 per event at a mean hadronic mass W of 4.2 GeV is observed. The ϱ0 production characteristics are determined as functions of pT, xF, and z. The ratio ϱ 0/"π 0" is found to be low at small z values consistent with centrally produced pions coming mainly from resonances. At large z values this ratio approaches 0.45 ± 0.15 which is compatible with a vector/pseudoscalar meson direct production ratio of one. The results are compared with those obtained from neutrino-proton interactions in the same experimental set-up.

Multi-step production of a diphoton resonance

NASA Astrophysics Data System (ADS)

Dobrescu, Bogdan A.; Fox, Patrick J.; Kearney, John

2017-06-01

Among the questions that would be raised by the observation of a new resonance at the LHC, particularly pressing are those concerning the production mechanism: What is the initial state? Is the resonance produced independently or in association with other particles? Here we present two weakly-coupled renormalizable models for production of a diphoton resonance that differ in both their initial and final states. In one model, a scalar particle produced through gluon fusion decays into a diphoton particle and a light, long-lived pseudoscalar. In another model, a {Z}\\prime boson produced from the annihilation of a strange-antistrange quark pair undergoes a cascade decay that leads to a diphoton particle and two sterile neutrinos. Various kinematic distributions may differentiate these models from the canonical model where a diphoton particle is directly produced in gluon fusion.

Redundancy of primary RNA-binding functions of the bacterial transcription terminator Rho.

PubMed

Shashni, Rajesh; Qayyum, M Zuhaib; Vishalini, V; Dey, Debashish; Sen, Ranjan

2014-09-01

The bacterial transcription terminator, Rho, terminates transcription at half of the operons. According to the classical model derived from in vitro assays on a few terminators, Rho is recruited to the transcription elongation complex (EC) by recognizing specific sites (rut) on the nascent RNA. Here, we explored the mode of in vivo recruitment process of Rho. We show that sequence specific recognition of the rut site, in majority of the Rho-dependent terminators, can be compromised to a great extent without seriously affecting the genome-wide termination function as well as the viability of Escherichia coli. These terminators function optimally only through a NusG-assisted recruitment and activation of Rho. Our data also indicate that at these terminators, Rho-EC-bound NusG interaction facilitates the isomerization of Rho into a translocase-competent form by stabilizing the interactions of mRNA with the secondary RNA binding site, thereby overcoming the defects of the primary RNA binding functions. © The Author(s) 2014. Published by Oxford University Press on behalf of Nucleic Acids Research.

RhoB-dependent modulation of postendocytic traffic in polarized Madin-Darby canine kidney cells.

PubMed

Rondanino, Christine; Rojas, Raul; Ruiz, Wily G; Wang, Exing; Hughey, Rebecca P; Dunn, Kenneth W; Apodaca, Gerard

2007-07-01

The Rho family of GTPases is implicated in the control of endocytic and biosynthetic traffic of many cell types; however, the cellular distribution of RhoB remains controversial and its function is not well understood. Using confocal microscopy, we found that endogenous RhoB and green fluorescent protein-tagged wild-type RhoB were localized to early endosomes, and to a much lesser extent to recycling endosomes, late endosomes or Golgi complex of fixed or live polarized Madin-Darby canine kidney cells. Consistent with RhoB localization to early endosomes, we observed that expression of dominant-negative RhoBN19 or dominant-active RhoBV14 altered postendocytic traffic of ligand-receptor complexes that undergo recycling, degradation or transcytosis. In vitro assays established that RhoB modulated the basolateral-to-apical transcytotic pathway by regulating cargo exit from basolateral early endosomes. Our results indicate that RhoB is localized, in part, to early endosomes where it regulates receptor egress through the early endocytic system.

The Role of Rho GTPases in Toxicity of Clostridium difficile Toxins

PubMed Central

Chen, Shuyi; Sun, Chunli; Wang, Haiying; Wang, Jufang

2015-01-01

Clostridium difficile (C. difficile) is the main cause of antibiotic-associated diarrhea prevailing in hospital settings. In the past decade, the morbidity and mortality of C. difficile infection (CDI) has increased significantly due to the emergence of hypervirulent strains. Toxin A (TcdA) and toxin B (TcdB), the two exotoxins of C. difficile, are the major virulence factors of CDI. The common mode of action of TcdA and TcdB is elicited by specific glucosylation of Rho-GTPase proteins in the host cytosol using UDP-glucose as a co-substrate, resulting in the inactivation of Rho proteins. Rho proteins are the key members in many biological processes and signaling pathways, inactivation of which leads to cytopathic and cytotoxic effects and immune responses of the host cells. It is supposed that Rho GTPases play an important role in the toxicity of C. difficile toxins. This review focuses on recent progresses in the understanding of functional consequences of Rho GTPases glucosylation induced by C. difficile toxins and the role of Rho GTPases in the toxicity of TcdA and TcdB. PMID:26633511

Cell wall integrity modulates RHO1 activity via the exchange factor ROM2.

PubMed Central

Bickle, M; Delley, P A; Schmidt, A; Hall, M N

1998-01-01

The essential phosphatidylinositol kinase homologue TOR2 of Saccharomyces cerevisiae controls the actin cytoskeleton by activating a GTPase switch consisting of RHO1 (GTPase), ROM2 (GEF) and SAC7 (GAP). We have identified two mutations, rot1-1 and rot2-1, that suppress the loss of TOR2 and are synthetic-lethal. The wild-type ROT1 and ROT2 genes and a multicopy suppressor, BIG1, were isolated by their ability to rescue the rot1-1 rot2-1 double mutant. ROT2 encodes glucosidase II, and ROT1 and BIG1 encode novel proteins. We present evidence that cell wall defects activate RHO1. First, rot1, rot2, big1, cwh41, gas1 and fks1 mutations all confer cell wall defects and suppress tor2(ts). Second, destabilizing the cell wall by supplementing the growth medium with 0.005% SDS also suppresses a tor2(ts) mutation. Third, disturbing the cell wall with SDS or a rot1, rot2, big1, cwh41, gas1 or fks1 mutation increases GDP/GTP exchange activity toward RHO1. These results suggest that cell wall defects suppress a tor2 mutation by activating RHO1 independently of TOR2, thereby inducing TOR2-independent polarization of the actin cytoskeleton and cell wall synthesis. Activation of RHO1, a subunit of the cell wall synthesis enzyme glucan synthase, by a cell wall alteration would ensure that cell wall synthesis occurs only when and where needed. The mechanism of RHO1 activation by a cell wall alteration is via the exchange factor ROM2 and could be analogous to signalling by integrin receptors in mammalian cells. PMID:9545237

Activation of G protein-coupled bile acid receptor, TGR5, induces smooth muscle relaxation via both Epac- and PKA-mediated inhibition of RhoA/Rho kinase pathway.

PubMed

Rajagopal, Senthilkumar; Kumar, Divya P; Mahavadi, Sunila; Bhattacharya, Sayak; Zhou, Ruizhe; Corvera, Carlos U; Bunnett, Nigel W; Grider, John R; Murthy, Karnam S

2013-03-01

The present study characterized the TGR5 expression and the signaling pathways coupled to this receptor that mediates the relaxation of gastric smooth muscle. TGR5 was detected in gastric muscle cells by RT-PCR and Western blotting. Treatment of cells with the TGR5-selective ligand oleanolic acid (OA) activated Gαs, but not Gαq, Gαi1, Gαi2, or Gαi3, and increased cAMP levels. OA did not elicit contraction, but caused relaxation of carbachol-induced contraction of gastric muscle cells from wild-type mice, but not tgr5(-/-) mice. OA, but not a selective exchange protein activated by cAMP (Epac) ligand (8-pCPT-2'-O-Me-cAMP), caused phosphorylation of RhoA and the phosphorylation was blocked by the PKA inhibitor, myristoylated PKI, and by the expression of phosphorylation-deficient mutant RhoA (S188A). Both OA and Epac ligand stimulated Ras-related protein 1 (Rap1) and inhibited carbachol (CCh)-induced Rho kinase activity. Expression of RhoA (S188A) or PKI partly reversed the inhibition of Rho kinase activity by OA but had no effect on inhibition by Epac ligand. However, suppression of Rap1 with siRNA blocked the inhibition of Rho kinase by Epac ligand, and partly reversed the inhibition by OA; the residual inhibition was blocked by PKI. Muscle relaxation in response to OA, but not Epac ligand, was partly reversed by PKI. We conclude that activation of TGR5 causes relaxation of gastric smooth muscle and the relaxation is mediated through inhibition of RhoA/Rho kinase pathway via both cAMP/Epac-dependent stimulation of Rap1 and cAMP/PKA-dependent phosphorylation of RhoA at Ser(188). TGR5 receptor activation on smooth muscle reveals a novel mechanism for the regulation of gut motility by bile acids.

Magnetic resonance spectroscopy of the canine brain at 3.0 T and 7.0 T.

PubMed

Martin-Vaquero, Paula; da Costa, Ronaldo C; Echandi, Rita L; Sammet, Christina L; Knopp, Michael V; Sammet, Steffen

2012-08-01

The purpose of this study was to evaluate the feasibility of proton magnetic resonance spectroscopy (1H MRS) to study the concentration of metabolites in the brain of dogs at 3.0 and 7.0 T. Four healthy male beagles were scanned using 3.0 T and 7.0 T human magnetic resonance imaging (MRI) units. The results obtained showed that all dogs had excellent quality spectra for a small (1 cm3) and large (8 cm3) voxel at 3.0 T, whereas only 2 dogs had high quality spectra at 7.0 T due to insufficient water suppression. 1H MRS at 3.0 T appears to be a reliable method to study metabolite concentrations in the canine brain. The development of more advanced water suppression techniques is necessary to improve the results at 7.0 T. Copyright © 2011 Elsevier Ltd. All rights reserved.

High concentrations of landiolol, a beta(1)-adrenoceptor antagonist, stimulate smooth muscle contraction of the rat trachea through the Rho-kinase pathway.

PubMed

Shibata, Osamu; Nishioka, Kenji; Yamaguchi, Masakazu; Makita, Tetsuji; Sumikawa, Koji

2008-01-01

Gradually progressing contraction of airway smooth muscle is suggested to be due to the Rho-kinase signaling pathway. In our preliminary study in rat tracheas, landiolol, a beta(1)-adrenoceptor antagonist, at high doses caused gradually progressing contraction, and this contraction reached a plateau after 20 min. Therefore, this study was carried out to clarify whether landiolol could stimulate the Rho-kinase pathway or the phosphatidylinositol (PI) response in the rat trachea. Seventy-eight male Wistar rats weighing 250-350 g were used for the experiments. Their tracheas were cut into 3-mm-wide ring segments or 1-mm-wide slices. Measurements of isometric tension and [(3)H] inositol monophosphate (IP(1)) production were conducted, using these tracheal rings or slices. Data values are expressed as means +/- SD, and statistical significance (P < 0.05) was determined using analysis of variance (ANOVA). Landiolol (700 microM)-induced contraction was completely inhibited by fasudil at 30 microM, while the landiolol-induced contraction was not inhibited by 4-diphenylacetoxy-N-methyl-piperidine methobromide (4-DAMP), ketanserin, or nicardipine. Landiolol did not stimulate IP(1) production. These results suggest that high concentrations of landiolol could cause airway smooth muscle contraction through the Rho-kinase pathway, but not through the PI response coupled with muscarinic M(3) receptors, 5-HT receptors or the activation of L-type Ca(2+) channels.

RhoG regulates anoikis through a phosphatidylinositol 3-kinase-dependent mechanism

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

Yamaki, Nao; Negishi, Manabu; Katoh, Hironori

2007-08-01

In normal epithelial cells, cell-matrix interaction is required for cell survival and proliferation, whereas disruption of this interaction causes epithelial cells to undergo apoptosis called anoikis. Here we show that the small GTPase RhoG plays an important role in the regulation of anoikis. HeLa cells are capable of anchorage-independent cell growth and acquire resistance to anoikis. We found that RNA interference-mediated knockdown of RhoG promoted anoikis in HeLa cells. Previous studies have shown that RhoG activates Rac1 and induces several cellular functions including promotion of cell migration through its effector ELMO and the ELMO-binding protein Dock180 that function as amore » Rac-specific guanine nucleotide exchange factor. However, RhoG-induced suppression of anoikis was independent of the ELMO- and Dock180-mediated activation of Rac1. On the other hand, the regulation of anoikis by RhoG required phosphatidylinositol 3-kinase (PI3K) activity, and constitutively active RhoG bound to the PI3K regulatory subunit p85{alpha} and induced the PI3K-dependent phosphorylation of Akt. Taken together, these results suggest that RhoG protects cells from apoptosis caused by the loss of anchorage through a PI3K-dependent mechanism, independent of its activation of Rac1.« less

Rho GTPases and their roles in cancer metabolism

PubMed Central

Wilson, Kristin F.; Erickson, Jon W.; Antonyak, Marc A.; Cerione, Richard A.

2013-01-01

Recently, the small molecule 968 was found to block the Rho GTPase-dependent growth of cancer cells in cell culture and mouse xenografts, and when the target of 968 was found to be mitochondrial enzyme glutaminase (GLS1) it revealed a surprising link between Rho GTPases and mitochondrial glutamine metabolism. Signal transduction via the Rho GTPases, together with NFκB, appears to elevate mitochondrial glutaminase activity in cancer cells, thereby helping cancer cells satisfy their altered metabolic demands. Here, we review what is known about the mechanism of glutaminase activation in cancer cells, as well as compare the properties of two distinct glutaminase inhibitors, and discuss recent findings that shed new light on how glutamine metabolism might affect cancer progression. PMID:23219172

Contribution of Rho kinase to the early phase of the calcium-contraction coupling in airway smooth muscle.

PubMed

Mbikou, Prisca; Fajmut, Ales; Brumen, Milan; Roux, Etienne

2011-02-01

We investigated theoretically and experimentally the role of Rho kinase (RhoK) in Ca(2+)-contraction coupling in rat airways. Isometric contraction was measured on tracheal, extrapulmonary and intrapulmonary bronchial rings. Intracellular [Ca(2+)] was recorded in freshly isolated tracheal myocytes. Stimulation by carbachol (0.3 and 10 μm) and 50 mm external KCl induced a short-time, Hill-shaped contraction obtained within 90 s, followed by a sustained or an additional delayed contraction. Responses of [Ca(2+)](i) to acetylcholine consisted in a fast peak followed by a plateau and, in 42% of the cells, superimposed Ca(2+) oscillations. The RhoK inhibitor Y27632 (10 μm) did not alter the [Ca(2+)](i) response. Whatever the agonist, Y27632 did not modify the basal tension but decreased the amplitude of the short-duration response, without altering the additional delayed contraction. The Myosin Light Chain Phosphatase (MLCP) inhibitor calyculin A increased the basal tension and abolished the effect of RhoK. KN93 (Ca(2+)-calmodulin-dependent protein kinase II inhibitor) and DIDS (inhibitor of Ca(2+)-activated Cl(-) channels) had no influence on the RhoK effect. We built a theoretical model of Ca(2+)-dependent active/inactive RhoK ratio and subsequent RhoK-dependent MLCP inactivation, which was further coupled with a four-state model of the contractile apparatus and Ca(2+)-dependent MLCK activation. The model explains the time course of the short-duration contraction and the role of RhoK by Ca(2+)-dependent activation of MLCK and RhoK, which inactivates MLCP. Oscillatory and non-oscillatory [Ca(2+)](i) responses result in a non-oscillatory contraction, the amplitude of which is encoded by the plateau value and oscillation frequency. In conclusion, Ca(2+)-dependent but CaMK II-independent RhoK activation contributes to the early phase of the contractile response via MLCP inhibition.

Thrombin-induced activation of RhoA in platelet shape change.

PubMed

Bodie, S L; Ford, I; Greaves, M; Nixon, G F

2001-09-14

Thrombin-induced activation of RhoA and its involvement in the regulation of myosin II light chain(20) phosphorylation (MLC-P) in alpha-toxin permeabilized platelets was investigated. Permeabilized platelets, expressing normal levels of P-selectin, displayed a Ca(2+)-dependent increase in shape change and MLC-P. Thrombin activated RhoA as measured by a rhotekin-binding assay within 30 s of stimulation under conditions of constant [Ca(2+)](i). Under the same conditions and timecourse, thrombin or GTPgammaS induced an increase in MLC-P and platelet shape change which was not dependent on an increase in [Ca(2+)](i). The thrombin- and GTPgammaS-induced MLC-P in constant [Ca(2+)](i) was inhibited by the addition of Y27632, a Rho-kinase inhibitor. This study directly demonstrates that thrombin can activate RhoA in platelets in a timecourse compatible with a role in increasing MLC-P and shape change (not involving an increase in [Ca(2+)](i)). This is also Rho-kinase-dependent. Copyright 2001 Academic Press.

Liquid chromatographic determination of chloramine-T and its primary degradation product, p-toluenesulfonamide, in water

USGS Publications Warehouse

Dawson, Verdel K.; Davis, Ruth A.

1997-01-01

N-sodium-N-chloro-rho-toluenesulfonamide (chloramine-T) effectively controls bacterial gill disease (BGD) in cultured fishes, BGD, a common disease of hatchery-reared salmonids, causes more fish losses than any other disease among these species. This study describes a liquid chromatographic (LC) method that is capable of direct, simultaneous analysis of chloramine-T and its primary degradation product, rho-toluenesulfonamide (rho-TSA), in water. The procedure involves reversed-phase (C-18) LC analysis with ion suppression, using 0.01 M phosphate buffer at pH 3. The mobile phase is phosphate buffer-acetonitrile (60 + 40) at 1 mL/min. Both chemicals can be detected with a UV spectrophotometer at 229 nm; the method is linear up to 40 mg, chloramine-T or rho-TSA/L. Mean recoveries were 96.4 +/- 6.1% for water samples fortified with 0.03 mg chloramine-T/L and 95.3 +/- 4.6% for water samples fortified with 0.005 mg rho-TSA/L. Limits of detection without sample enrichment for chloramine-T and rho-TSA are 0.01 mg/L and 0.001 mg/L, respectively.

Liquid chromatographic determination of chloramine-T and its primary degradation product, p-toluenesulfonamide, in water

USGS Publications Warehouse

Dawson, V.K.; Davis, R.A.

1997-01-01

N-sodium-N-chloro-rho-toluenesulfonamide (chloramine-T) effectively controls bacterial gill disease (BGD) in cultured fishes, BGD, a common disease of hatchery-reared salmonids, causes more fish losses than any other disease among these species, This study describes a liquid chromatographic (LC) method that is capable of direct, simultaneous analysis of chloramine-T and its primary degradation product, rho-toluenesulfonamide (rho-TSA), in water. The procedure involves reversed-phase (C-18) LC analysis with ion suppression, using 0.01 M phosphate buffer at pH 3. The mobile phase is phosphate buffer-acetonitrile (60 + 40) at 1 mL/min. Both chemicals can be detected with a UV spectrophotometer at 229 nm; the method is linear up to 40 mg, chloramine-T or rho-TSA/L. Mean recoveries were 96.4 +/- 6.1% for water samples fortified with 0.03 mg chloramine-T/L and 95.3 +/- 4.6% for water samples fortified with 0.005 mg rho-TSA/L. Limits of detection without sample enrichment for chloramine-T and rho-TSA are 0.01 mg/L and 0.001 mg/L, respectively.

CYK-4 regulates Rac, but not Rho, during cytokinesis

PubMed Central

Zhuravlev, Yelena; Hirsch, Sophia M.; Jordan, Shawn N.; Dumont, Julien; Shirasu-Hiza, Mimi; Canman, Julie C.

2017-01-01

Cytokinesis is driven by constriction of an actomyosin contractile ring that is controlled by Rho-family small GTPases. Rho, activated by the guanine-nucleotide exchange factor ECT-2, is upstream of both myosin-II activation and diaphanous formin-mediated filamentous actin (f-actin) assembly, which drive ring constriction. The role for Rac and its regulators is more controversial, but, based on the finding that Rac inactivation can rescue cytokinesis failure when the GTPase-activating protein (GAP) CYK-4 is disrupted, Rac activity was proposed to be inhibitory to contractile ring constriction and thus specifically inactivated by CYK-4 at the division plane. An alternative model proposes that Rac inactivation generally rescues cytokinesis failure by reducing cortical tension, thus making it easier for the cell to divide when ring constriction is compromised. In this alternative model, CYK-4 was instead proposed to activate Rho by binding ECT-2. Using a combination of time-lapse in vivo single-cell analysis and Caenorhabditis elegans genetics, our evidence does not support this alternative model. First, we found that Rac disruption does not generally rescue cytokinesis failure: inhibition of Rac specifically rescues cytokinesis failure due to disruption of CYK-4 or ECT-2 but does not rescue cytokinesis failure due to disruption of two other contractile ring components, the Rho effectors diaphanous formin and myosin-II. Second, if CYK-4 regulates cytokinesis through Rho rather than Rac, then CYK-4 inhibition should decrease levels of downstream targets of Rho. Inconsistent with this, we found no change in the levels of f-actin or myosin-II at the division plane when CYK-4 GAP activity was reduced, suggesting that CYK-4 is not upstream of ECT-2/Rho activation. Instead, we found that the rescue of cytokinesis in CYK-4 mutants by Rac inactivation was Cdc42 dependent. Together our data suggest that CYK-4 GAP activity opposes Rac (and perhaps Cdc42) during cytokinesis

Enhanced p122RhoGAP/DLC-1 Expression Can Be a Cause of Coronary Spasm

PubMed Central

Kinjo, Takahiko; Tanaka, Makoto; Osanai, Tomohiro; Shibutani, Shuji; Narita, Ikuyo; Tanno, Tomohiro; Nishizaki, Kimitaka; Ichikawa, Hiroaki; Kimura, Yoshihiro; Ishida, Yuji; Yokota, Takashi; Shimada, Michiko; Homma, Yoshimi; Tomita, Hirofumi; Okumura, Ken

2015-01-01

Background We previously showed that phospholipase C (PLC)-δ1 activity was enhanced by 3-fold in patients with coronary spastic angina (CSA). We also reported that p122Rho GTPase-activating protein/deleted in liver cancer-1 (p122RhoGAP/DLC-1) protein, which was discovered as a PLC-δ1 stimulator, was upregulated in CSA patients. We tested the hypothesis that p122RhoGAP/DLC-1 overexpression causes coronary spasm. Methods and Results We generated transgenic (TG) mice with vascular smooth muscle (VSM)-specific overexpression of p122RhoGAP/DLC-1. The gene and protein expressions of p122RhoGAP/DLC-1 were markedly increased in the aorta of homozygous TG mice. Stronger staining with anti-p122RhoGAP/DLC-1 in the coronary artery was found in TG than in WT mice. PLC activities in the plasma membrane fraction and the whole cell were enhanced by 1.43 and 2.38 times, respectively, in cultured aortic vascular smooth muscle cells from homozygous TG compared with those from WT mice. Immediately after ergometrine injection, ST-segment elevation was observed in 1 of 7 WT (14%), 6 of 7 heterozygous TG (84%), and 7 of 7 homozygous TG mice (100%) (p<0.05, WT versus TGs). In the isolated Langendorff hearts, coronary perfusion pressure was increased after ergometrine in TG, but not in WT mice, despite of the similar response to prostaglandin F2α between TG and WT mice (n = 5). Focal narrowing of the coronary artery after ergometrine was documented only in TG mice. Conclusions VSM-specific overexpression of p122RhoGAP/DLC-1 enhanced coronary vasomotility after ergometrine injection in mice, which is relevant to human CSA. PMID:26624289

Binding and Translocation of Termination Factor Rho Studied at the Single-Molecule Level

PubMed Central

Koslover, Daniel J.; Fazal, Furqan M.; Mooney, Rachel A.; Landick, Robert; Block, Steven M.

2012-01-01

Rho termination factor is an essential hexameric helicase responsible for terminating 20–50% of all mRNA synthesis in E. coli. We used single- molecule force spectroscopy to investigate Rho-RNA binding interactions at the Rho- utilization (rut) site of the ? tR1 terminator. Our results are consistent with Rho complexes adopting two states, one that binds 57 ±2 nucleotides of RNA across all six of the Rho primary binding sites, and another that binds 85 ±2 nucleotides at the six primary sites plus a single secondary site situated at the center of the hexamer. The single-molecule data serve to establish that Rho translocates 5′-to-3′ towards RNA polymerase (RNAP) by a tethered-tracking mechanism, looping out the intervening RNA between the rut site and RNAP. These findings lead to a general model for Rho binding and translocation, and establish a novel experimental approach that should facilitate additional single- molecule studies of RNA-binding proteins. PMID:22885804

BAR domain proteins regulate Rho GTPase signaling.

PubMed

Aspenström, Pontus

2014-01-01

BAR proteins comprise a heterogeneous group of multi-domain proteins with diverse biological functions. The common denominator is the Bin-Amphiphysin-Rvs (BAR) domain that not only confers targeting to lipid bilayers, but also provides scaffolding to mold lipid membranes into concave or convex surfaces. This function of BAR proteins is an important determinant in the dynamic reconstruction of membrane vesicles, as well as of the plasma membrane. Several BAR proteins function as linkers between cytoskeletal regulation and membrane dynamics. These links are provided by direct interactions between BAR proteins and actin-nucleation-promoting factors of the Wiskott-Aldrich syndrome protein family and the Diaphanous-related formins. The Rho GTPases are key factors for orchestration of this intricate interplay. This review describes how BAR proteins regulate the activity of Rho GTPases, as well as how Rho GTPases regulate the function of BAR proteins. This mutual collaboration is a central factor in the regulation of vital cellular processes, such as cell migration, cytokinesis, intracellular transport, endocytosis, and exocytosis.

De novo variants in RHOBTB2, an atypical Rho GTPase gene, cause epileptic encephalopathy.

PubMed

Belal, Hazrat; Nakashima, Mitsuko; Matsumoto, Hiroshi; Yokochi, Kenji; Taniguchi-Ikeda, Mariko; Aoto, Kazushi; Amin, Mohammed Badrul; Maruyama, Azusa; Nagase, Hiroaki; Mizuguchi, Takeshi; Miyatake, Satoko; Miyake, Noriko; Iijima, Kazumoto; Nonoyama, Shigeaki; Matsumoto, Naomichi; Saitsu, Hirotomo

2018-05-16

By whole exome sequencing, we identified three de novo RHOBTB2 variants in three patients with epileptic encephalopathies (EEs). Interestingly, all three patients showed acute encephalopathy (febrile status epilepticus), with magnetic resonance imaging revealing hemisphere swelling or reduced diffusion in various brain regions. RHOBTB2 encodes Rho-related BTB domain-containing protein 2, an atypical Rho GTPase that is a substrate-specific adaptor or itself is a substrate for the Cullin-3 (CUL3)-based ubiquitin/proteasome complex. Transient expression experiments in Neuro-2a cells revealed that mutant RHOBTB2 was more abundant than wild-type RHOBTB2. Co-expression of CUL3 with RHOBTB2 decreased the level of wild-type RHOBTB2 but not the level of any of the three mutants, indicating impaired CUL3 complex-dependent degradation of the three mutants. These data indicate that RHOBTB2 variants are a rare genetic cause of EEs, in which acute encephalopathy might be a characteristic feature, and that precise regulation of RHOBTB2 levels is essential for normal brain function. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

The new Be-type star HD 147196 in the Rho Ophiuchi dark cloud region

NASA Technical Reports Server (NTRS)

The, P. S.; Perez, M. R.; De Winter, D.; Van Den Ancker, M. E.

1993-01-01

The newly discovered hot-emission line star, HD 147196 in the Rho Oph dark cloud region was observed spectroscopically and photometrically and high and low resolution IUE spectra were obtained. The finding of Irvine (1990) that this relatively bright star show its H-alpha-line in emission is confirmed. Previous H-alpha-surveys of the Rho Oph star-forming region did not detect HD 147196 as an H-alpha-emission star, meaning that it must recently be very active and has perhaps transformed itself from a B-type star at shell phase to a Be-phase. The Mg II h + k resonance lines are in absorption and they appear to be interstellar in nature, which means that either the abundance of Mg in the extended atmosphere of the star is low or that the shell is not extended enough to produce emission lines of Mg II. Photometric observations of this B8 V type star do not show any variations during at least the years covered by our monitoring or any excess of NIR radiation in its spectral energy distribution up to the M-passband at 4.8 microns.

IκB Kinase γ/Nuclear Factor-κB-Essential Modulator (IKKγ/NEMO) Facilitates RhoA GTPase Activation, which, in Turn, Activates Rho-associated Kinase (ROCK) to Phosphorylate IKKβ in Response to Transforming Growth Factor (TGF)-β1*

PubMed Central

Kim, Hee-Jun; Kim, Jae-Gyu; Moon, Mi-Young; Park, Seol-Hye; Park, Jae-Bong

2014-01-01

Transforming growth factor (TGF)-β1 plays several roles in a variety of cellular functions. TGF-β1 transmits its signal through Smad transcription factor-dependent and -independent pathways. It was reported that TGF-β1 activates NF-κB and RhoA, and RhoA activates NF-κB in several kinds of cells in a Smad-independent pathway. However, the activation molecular mechanism of NF-κB by RhoA upon TGF-β1 has not been clearly elucidated. We observed that RhoA-GTP level was increased by TGF-β1 in RAW264.7 cells. RhoA-GDP and RhoGDI were bound to N- and C-terminal domains of IKKγ, respectively. Purified IKKγ facilitated GTP binding to RhoA complexed with RhoGDI. Furthermore, Dbs, a guanine nucletotide exchange factor of RhoA much more enhanced GTP binding to RhoA complexed with RhoGDI in the presence of IKKγ. Indeed, si-IKKγ abolished RhoA activation in response to TGF-β1 in cells. However, TGF-β1 stimulated the release of RhoA-GTP from IKKγ and Rho-associated kinase (ROCK), an active RhoA effector protein, directly phosphorylated IKKβ in vitro, whereas TGF-β1-activated kinase 1 activated RhoA upon TGF-β1 stimulation. Taken together, our data indicate that IKKγ facilitates RhoA activation via a guanine nucletotide exchange factor, which in turn activates ROCK to phosphorylate IKKβ, leading to NF-κB activation that induced the chemokine expression and cell migration upon TGF-β1. PMID:24240172

FgBud3, a Rho4-Interacting Guanine Nucleotide Exchange Factor, Is Involved in Polarity Growth, Cell Division and Pathogenicity of Fusarium graminearum.

PubMed

Zhang, Chengkang; Luo, Zenghong; He, Dongdong; Su, Li; Yin, Hui; Wang, Guo; Liu, Hong; Rensing, Christopher; Wang, Zonghua

2018-01-01

Rho GTPases are signaling macromolecules that are associated with developmental progression and pathogenesis of Fusarium graminearum . Generally, enzymatic activities of Rho GTPases are regulated by Rho GTPase guanine nucleotide exchange factors (RhoGEFs). In this study, we identified a putative RhoGEF encoding gene ( FgBUD3 ) in F. graminearum database and proceeded further by using a functional genetic approach to generate FgBUD3 targeted gene deletion mutant. Phenotypic analysis results showed that the deletion of FgBUD3 caused severe reduction in growth of FgBUD3 mutant generated during this study. We also observed that the deletion of FgBUD3 completely abolished sexual reproduction and triggered the production of abnormal asexual spores with nearly no septum in ΔFgbud3 strain. Further results obtained from infection assays conducted during this research revealed that the FgBUD3 defective mutant lost its pathogenicity on wheat and hence, suggests FgBud3 plays an essential role in the pathogenicity of F. graminearum . Additional, results derived from yeast two-hybrid assays revealed that FgBud3 strongly interacted with FgRho4 compared to the interaction with FgRho2, FgRho3, and FgCdc42. Moreover, we found that FgBud3 interacted with both GTP-bound and GDP-bound form of FgRho4. From these results, we subsequently concluded that, the Rho4-interacting GEF protein FgBud3 crucially promotes vegetative growth, asexual and sexual development, cell division and pathogenicity in F. graminearum .

Problem-Solving Test: The Mechanism of Transcription Termination by the Rho Factor

ERIC Educational Resources Information Center

Szeberenyi, Jozsef

2012-01-01

Transcription termination comes in two forms in "E. coli" cells. Rho-dependent termination requires the binding of a termination protein called Rho factor to the transcriptional machinery at the terminator region, whereas Rho-independent termination is achieved by conformational changes in the transcript itself. This article presents a test…

Acting on Actin: Rac and Rho Played by Yersinia.

PubMed

Aepfelbacher, Martin; Wolters, Manuel

2017-01-01

Pathogenic bacteria of the genus Yersinia include Y. pestis-the agent of plaque-and two enteropathogens, Y. enterocolitica, and Y. pseudotuberculosis. These pathogens have developed an array of virulence factors aimed at manipulating Rho GTP-binding proteins and the actin cytoskeleton in host cells to cross the intestinal barrier and suppress the immune system. Yersinia virulence factors include outer membrane proteins triggering cell invasion by binding to integrins, effector proteins injected into host cells to manipulate Rho protein functions and a Rho protein-activating exotoxin. Here, we present an overview of how Yersinia and host factors are integrated in a regulatory network that orchestrates the subversion of host defense.

RhoB controls endothelial barrier recovery by inhibiting Rac1 trafficking to the cell border

PubMed Central

Marcos-Ramiro, Beatriz; García-Weber, Diego; Barroso, Susana; Feito, Jorge; Ortega, María C.; Cernuda-Morollón, Eva; Reglero-Real, Natalia; Fernández-Martín, Laura; Durán, Maria C.; Alonso, Miguel A.; Correas, Isabel; Cox, Susan; Ridley, Anne J.

2016-01-01

Endothelial barrier dysfunction underlies chronic inflammatory diseases. In searching for new proteins essential to the human endothelial inflammatory response, we have found that the endosomal GTPase RhoB is up-regulated in response to inflammatory cytokines and expressed in the endothelium of some chronically inflamed tissues. We show that although RhoB and the related RhoA and RhoC play additive and redundant roles in various aspects of endothelial barrier function, RhoB specifically inhibits barrier restoration after acute cell contraction by preventing plasma membrane extension. During barrier restoration, RhoB trafficking is induced between vesicles containing RhoB nanoclusters and plasma membrane protrusions. The Rho GTPase Rac1 controls membrane spreading and stabilizes endothelial barriers. We show that RhoB colocalizes with Rac1 in endosomes and inhibits Rac1 activity and trafficking to the cell border during barrier recovery. Inhibition of endosomal trafficking impairs barrier reformation, whereas induction of Rac1 translocation to the plasma membrane accelerates it. Therefore, RhoB-specific regulation of Rac1 trafficking controls endothelial barrier integrity during inflammation. PMID:27138256

π π → π γ * amplitude and the resonant ρ → π γ * transition from lattice QCD

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

Briceño, Raúl A.; Dudek, Jozef J.; Edwards, Robert G.

2016-06-01

We present a determination of themore » $P$-wave $$\\pi\\pi\\to\\pi\\gamma^\\star$$ transition amplitude from lattice quantum chromodynamics. Matrix elements of the vector current in a finite-volume are extracted from three-point correlation functions, and from these we determine the infinite-volume amplitude using a generalization of the Lellouch-L\\"uscher formalism. We determine the amplitude for a range of discrete values of the $$\\pi\\pi$$ energy and virtuality of the photon, and observe the expected dynamical enhancement due to the $$\\rho$$ resonance. Describing the energy dependence of the amplitude, we are able to analytically continue into the complex energy plane and from the residue at the $$\\rho$$ pole extract the $$\\rho\\to\\gamma^\\star\\pi$$ transition form factor. This calculation, at $$m_\\pi\\approx 400$$~MeV, is the first time a form factor of a hadron resonance has been calculated within a first-principles approach to QCD.« less

Activation of G protein-coupled bile acid receptor, TGR5, induces smooth muscle relaxation via both Epac- and PKA-mediated inhibition of RhoA/Rho kinase pathway

PubMed Central

Rajagopal, Senthilkumar; Kumar, Divya P.; Mahavadi, Sunila; Bhattacharya, Sayak; Zhou, Ruizhe; Corvera, Carlos U.; Bunnett, Nigel W.; Grider, John R.

2013-01-01

The present study characterized the TGR5 expression and the signaling pathways coupled to this receptor that mediates the relaxation of gastric smooth muscle. TGR5 was detected in gastric muscle cells by RT-PCR and Western blotting. Treatment of cells with the TGR5-selective ligand oleanolic acid (OA) activated Gαs, but not Gαq, Gαi1, Gαi2, or Gαi3, and increased cAMP levels. OA did not elicit contraction, but caused relaxation of carbachol-induced contraction of gastric muscle cells from wild-type mice, but not tgr5−/− mice. OA, but not a selective exchange protein activated by cAMP (Epac) ligand (8-pCPT-2′-O-Me-cAMP), caused phosphorylation of RhoA and the phosphorylation was blocked by the PKA inhibitor, myristoylated PKI, and by the expression of phosphorylation-deficient mutant RhoA (S188A). Both OA and Epac ligand stimulated Ras-related protein 1 (Rap1) and inhibited carbachol (CCh)-induced Rho kinase activity. Expression of RhoA (S188A) or PKI partly reversed the inhibition of Rho kinase activity by OA but had no effect on inhibition by Epac ligand. However, suppression of Rap1 with siRNA blocked the inhibition of Rho kinase by Epac ligand, and partly reversed the inhibition by OA; the residual inhibition was blocked by PKI. Muscle relaxation in response to OA, but not Epac ligand, was partly reversed by PKI. We conclude that activation of TGR5 causes relaxation of gastric smooth muscle and the relaxation is mediated through inhibition of RhoA/Rho kinase pathway via both cAMP/Epac-dependent stimulation of Rap1 and cAMP/PKA-dependent phosphorylation of RhoA at Ser188. TGR5 receptor activation on smooth muscle reveals a novel mechanism for the regulation of gut motility by bile acids. PMID:23275618

The Nebivolol action on vascular tone is dependent on actin cytoskeleton polymerization and Rho-A activity into ECs and SMCs.

PubMed

Kadi, A; de Isla, N; Moby, V; Lacolley, P; Labrude, P; Stoltz, J F; Menu, P

2014-01-01

Nitric oxide is implicated in the target action of Nebivolol, a selective β1 adrenoceptor blocker used in hypertension treatment. As the Nitric Oxide (NO) production and the actin cytoskeleton are linked, the aim of this work was to study the involvement of actin cytoskeleton on mechanism of action of Nebivolol in cultured endothelial cells. We studied the effect of Nebivolol (200 μM) on actin filaments remodeling and its impact on NO production and eNOS activation. Results showed that Nebivolol perturbs actin filaments polymerization, increases NO production and eNOS activity between 30 minutes and 1 h. Stabilization of actin filaments with phalloïdine (50 μM) abolishes Nebivolol effects on eNOS activation and NO production. Furthermore, Rho-kinase activity decreased during the first hour of Nebivolol treatment, then increased after 3 h, while actin filaments repolymerized, eNOS activation and NO production decreased. In SMCs, Nebivolol induced a decrease in the Rho-kinase activity from 1 h until 24 h of incubation. In conclusion, we suggest that Nebivolol induced NO production in Endothelial Cells (ECs) via complementary actions between actin cytoskeleton remodeling inducing eNOS activation and Rho-kinase implication. The effect of Nebivolol on ECs occurs during the first hour, this effect on SMCs seems to be maintained until 24 h, explaining persisted action of Nebivolol observed in vivo.

The interdependence of the Rho GTPases and apicobasal cell polarity.

PubMed

Mack, Natalie Ann; Georgiou, Marios

2014-01-01

Signaling via the Rho GTPases provides crucial regulation of numerous cell polarization events, including apicobasal (AB) polarity, polarized cell migration, polarized cell division and neuronal polarity. Here we review the relationships between the Rho family GTPases and epithelial AB polarization events, focusing on the 3 best-characterized members: Rho, Rac and Cdc42. We discuss a multitude of processes that are important for AB polarization, including lumen formation, apical membrane specification, cell-cell junction assembly and maintenance, as well as tissue polarity. Our discussions aim to highlight the immensely complex regulatory mechanisms that encompass Rho GTPase signaling during AB polarization. More specifically, in this review we discuss several emerging common themes, that include: 1) the need for Rho GTPase activities to be carefully balanced in both a spatial and temporal manner through a multitude of mechanisms; 2) the existence of signaling feedback loops and crosstalk to create robust cellular responses; and 3) the frequent multifunctionality that exists among AB polarity regulators. Regarding this latter theme, we provide further discussion of the potential plasticity of the cell polarity machinery and as a result the possible implications for human disease.

Studies of the resonance structure in D0→KS0K±π∓ decays

NASA Astrophysics Data System (ADS)

Aaij, R.; Adeva, B.; Adinolfi, M.; Affolder, A.; Ajaltouni, Z.; Akar, S.; Albrecht, J.; Alessio, F.; Alexander, M.; Ali, S.; Alkhazov, G.; Alvarez Cartelle, P.; Alves, A. A.; Amato, S.; Amerio, S.; Amhis, Y.; An, L.; Anderlini, L.; Anderson, J.; Andreassi, G.; Andreotti, M.; Andrews, J. E.; Appleby, R. B.; Aquines Gutierrez, O.; Archilli, F.; d'Argent, P.; Artamonov, A.; Artuso, M.; Aslanides, E.; Auriemma, G.; Baalouch, M.; Bachmann, S.; Back, J. J.; Badalov, A.; Baesso, C.; Baldini, W.; Barlow, R. J.; Barschel, C.; Barsuk, S.; Barter, W.; Batozskaya, V.; Battista, V.; Bay, A.; Beaucourt, L.; Beddow, J.; Bedeschi, F.; Bediaga, I.; Bel, L. J.; Bellee, V.; Belyaev, I.; Ben-Haim, E.; Bencivenni, G.; Benson, S.; Benton, J.; Berezhnoy, A.; Bernet, R.; Bertolin, A.; Bettler, M.-O.; van Beuzekom, M.; Bien, A.; Bifani, S.; Bird, T.; Birnkraut, A.; Bizzeti, A.; Blake, T.; Blanc, F.; Blouw, J.; Blusk, S.; Bocci, V.; Bondar, A.; Bondar, N.; Bonivento, W.; Borghi, S.; Borsato, M.; Bowcock, T. J. V.; Bowen, E.; Bozzi, C.; Braun, S.; Brett, D.; Britsch, M.; Britton, T.; Brodzicka, J.; Brook, N. H.; Buchanan, E.; Bursche, A.; Buytaert, J.; Cadeddu, S.; Calabrese, R.; Calvi, M.; Calvo Gomez, M.; Campana, P.; Campora Perez, D.; Capriotti, L.; Carbone, A.; Carboni, G.; Cardinale, R.; Cardini, A.; Carniti, P.; Carson, L.; Carvalho Akiba, K.; Casse, G.; Cassina, L.; Castillo Garcia, L.; Cattaneo, M.; Cauet, Ch.; Cavallero, G.; Cenci, R.; Charles, M.; Charpentier, Ph.; Chefdeville, M.; Chen, S.; Cheung, S.-F.; Chiapolini, N.; Chrzaszcz, M.; Cid Vidal, X.; Ciezarek, G.; Clarke, P. E. L.; Clemencic, M.; Cliff, H. V.; Closier, J.; Coco, V.; Cogan, J.; Cogneras, E.; Cogoni, V.; Cojocariu, L.; Collazuol, G.; Collins, P.; Comerma-Montells, A.; Contu, A.; Cook, A.; Coombes, M.; Coquereau, S.; Corti, G.; Corvo, M.; Couturier, B.; Cowan, G. A.; Craik, D. C.; Crocombe, A.; Cruz Torres, M.; Cunliffe, S.; Currie, R.; D'Ambrosio, C.; Dall'Occo, E.; Dalseno, J.; David, P. N. Y.; Davis, A.; De Aguiar Francisco, O.; De Bruyn, K.; De Capua, S.; De Cian, M.; De Miranda, J. M.; De Paula, L.; De Simone, P.; Dean, C.-T.; Decamp, D.; Deckenhoff, M.; Del Buono, L.; Déléage, N.; Demmer, M.; Derkach, D.; Deschamps, O.; Dettori, F.; Dey, B.; Di Canto, A.; Di Ruscio, F.; Dijkstra, H.; Donleavy, S.; Dordei, F.; Dorigo, M.; Dosil Suárez, A.; Dossett, D.; Dovbnya, A.; Dreimanis, K.; Dufour, L.; Dujany, G.; Dupertuis, F.; Durante, P.; Dzhelyadin, R.; Dziurda, A.; Dzyuba, A.; Easo, S.; Egede, U.; Egorychev, V.; Eidelman, S.; Eisenhardt, S.; Eitschberger, U.; Ekelhof, R.; Eklund, L.; El Rifai, I.; Elsasser, Ch.; Ely, S.; Esen, S.; Evans, H. M.; Evans, T.; Falabella, A.; Färber, C.; Farinelli, C.; Farley, N.; Farry, S.; Fay, R.; Ferguson, D.; Fernandez Albor, V.; Ferrari, F.; Ferreira Rodrigues, F.; Ferro-Luzzi, M.; Filippov, S.; Fiore, M.; Fiorini, M.; Firlej, M.; Fitzpatrick, C.; Fiutowski, T.; Fohl, K.; Fol, P.; Fontana, M.; Fontanelli, F.; Forty, R.; Frank, M.; Frei, C.; Frosini, M.; Fu, J.; Furfaro, E.; Gallas Torreira, A.; Galli, D.; Gallorini, S.; Gambetta, S.; Gandelman, M.; Gandini, P.; Gao, Y.; García Pardiñas, J.; Garra Tico, J.; Garrido, L.; Gascon, D.; Gaspar, C.; Gauld, R.; Gavardi, L.; Gazzoni, G.; Gerick, D.; Gersabeck, E.; Gersabeck, M.; Gershon, T.; Ghez, Ph.; Gianı, S.; Gibson, V.; Girard, O. G.; Giubega, L.; Gligorov, V. V.; Göbel, C.; Golubkov, D.; Golutvin, A.; Gomes, A.; Gotti, C.; Grabalosa Gándara, M.; Graciani Diaz, R.; Granado Cardoso, L. A.; Graugés, E.; Graverini, E.; Graziani, G.; Grecu, A.; Greening, E.; Gregson, S.; Griffith, P.; Grillo, L.; Grünberg, O.; Gui, B.; Gushchin, E.; Guz, Yu.; Gys, T.; Hadavizadeh, T.; Hadjivasiliou, C.; Haefeli, G.; Haen, C.; Haines, S. C.; Hall, S.; Hamilton, B.; Han, X.; Hansmann-Menzemer, S.; Harnew, N.; Harnew, S. T.; Harrison, J.; He, J.; Head, T.; Heijne, V.; Hennessy, K.; Henrard, P.; Henry, L.; van Herwijnen, E.; Heß, M.; Hicheur, A.; Hill, D.; Hoballah, M.; Hombach, C.; Hulsbergen, W.; Humair, T.; Hussain, N.; Hutchcroft, D.; Hynds, D.; Idzik, M.; Ilten, P.; Jacobsson, R.; Jaeger, A.; Jalocha, J.; Jans, E.; Jawahery, A.; Jing, F.; John, M.; Johnson, D.; Jones, C. R.; Joram, C.; Jost, B.; Jurik, N.; Kandybei, S.; Kanso, W.; Karacson, M.; Karbach, T. M.; Karodia, S.; Kecke, M.; Kelsey, M.; Kenyon, I. R.; Kenzie, M.; Ketel, T.; Khanji, B.; Khurewathanakul, C.; Klaver, S.; Klimaszewski, K.; Kochebina, O.; Kolpin, M.; Komarov, I.; Koopman, R. F.; Koppenburg, P.; Kozeiha, M.; Kravchuk, L.; Kreplin, K.; Kreps, M.; Krocker, G.; Krokovny, P.; Kruse, F.; Kucewicz, W.; Kucharczyk, M.; Kudryavtsev, V.; Kuonen, A. K.; Kurek, K.; Kvaratskheliya, T.; Lacarrere, D.; Lafferty, G.; Lai, A.; Lambert, D.; Lanfranchi, G.; Langenbruch, C.; Langhans, B.; Latham, T.; Lazzeroni, C.; Le Gac, R.; van Leerdam, J.; Lees, J.-P.; Lefèvre, R.; Leflat, A.; Lefrançois, J.; Leroy, O.; Lesiak, T.; Leverington, B.; Li, Y.; Likhomanenko, T.; Liles, M.; Lindner, R.; Linn, C.; Lionetto, F.; Liu, B.; Liu, X.; Loh, D.; Lohn, S.; Longstaff, I.; Lopes, J. H.; Lucchesi, D.; Lucio Martinez, M.; Luo, H.; Lupato, A.; Luppi, E.; Lupton, O.; Lusiani, A.; Machefert, F.; Maciuc, F.; Maev, O.; Maguire, K.; Malde, S.; Malinin, A.; Manca, G.; Mancinelli, G.; Manning, P.; Mapelli, A.; Maratas, J.; Marchand, J. F.; Marconi, U.; Marin Benito, C.; Marino, P.; Märki, R.; Marks, J.; Martellotti, G.; Martin, M.; Martinelli, M.; Martinez Santos, D.; Martinez Vidal, F.; Martins Tostes, D.; Massafferri, A.; Matev, R.; Mathad, A.; Mathe, Z.; Matteuzzi, C.; Mauri, A.; Maurin, B.; Mazurov, A.; McCann, M.; McCarthy, J.; McNab, A.; McNulty, R.; Meadows, B.; Meier, F.; Meissner, M.; Melnychuk, D.; Merk, M.; Michielin, E.; Milanes, D. A.; Minard, M.-N.; Mitzel, D. S.; Molina Rodriguez, J.; Monroy, I. A.; Monteil, S.; Morandin, M.; Morawski, P.; Mordà, A.; Morello, M. J.; Moron, J.; Morris, A. B.; Mountain, R.; Muheim, F.; Müller, D.; Müller, J.; Müller, K.; Müller, V.; Mussini, M.; Muster, B.; Naik, P.; Nakada, T.; Nandakumar, R.; Nandi, A.; Nasteva, I.; Needham, M.; Neri, N.; Neubert, S.; Neufeld, N.; Neuner, M.; Nguyen, A. D.; Nguyen, T. D.; Nguyen-Mau, C.; Niess, V.; Niet, R.; Nikitin, N.; Nikodem, T.; Novoselov, A.; O'Hanlon, D. P.; Oblakowska-Mucha, A.; Obraztsov, V.; Ogilvy, S.; Okhrimenko, O.; Oldeman, R.; Onderwater, C. J. G.; Osorio Rodrigues, B.; Otalora Goicochea, J. M.; Otto, A.; Owen, P.; Oyanguren, A.; Palano, A.; Palombo, F.; Palutan, M.; Panman, J.; Papanestis, A.; Pappagallo, M.; Pappalardo, L. L.; Pappenheimer, C.; Parkes, C.; Passaleva, G.; Patel, G. D.; Patel, M.; Patrignani, C.; Pearce, A.; Pellegrino, A.; Penso, G.; Pepe Altarelli, M.; Perazzini, S.; Perret, P.; Pescatore, L.; Petridis, K.; Petrolini, A.; Petruzzo, M.; Picatoste Olloqui, E.; Pietrzyk, B.; Pilař, T.; Pinci, D.; Pistone, A.; Piucci, A.; Playfer, S.; Plo Casasus, M.; Poikela, T.; Polci, F.; Poluektov, A.; Polyakov, I.; Polycarpo, E.; Popov, A.; Popov, D.; Popovici, B.; Potterat, C.; Price, E.; Price, J. D.; Prisciandaro, J.; Pritchard, A.; Prouve, C.; Pugatch, V.; Puig Navarro, A.; Punzi, G.; Qian, W.; Quagliani, R.; Rachwal, B.; Rademacker, J. H.; Rama, M.; Rangel, M. S.; Raniuk, I.; Rauschmayr, N.; Raven, G.; Redi, F.; Reichert, S.; Reid, M. M.; dos Reis, A. C.; Ricciardi, S.; Richards, S.; Rihl, M.; Rinnert, K.; Rives Molina, V.; Robbe, P.; Rodrigues, A. B.; Rodrigues, E.; Rodriguez Lopez, J. A.; Rodriguez Perez, P.; Roiser, S.; Romanovsky, V.; Romero Vidal, A.; Ronayne, J. W.; Rotondo, M.; Rouvinet, J.; Ruf, T.; Ruiz, H.; Ruiz Valls, P.; Saborido Silva, J. J.; Sagidova, N.; Sail, P.; Saitta, B.; Salustino Guimaraes, V.; Sanchez Mayordomo, C.; Sanmartin Sedes, B.; Santacesaria, R.; Santamarina Rios, C.; Santimaria, M.; Santovetti, E.; Sarti, A.; Satriano, C.; Satta, A.; Saunders, D. M.; Savrina, D.; Schiller, M.; Schindler, H.; Schlupp, M.; Schmelling, M.; Schmelzer, T.; Schmidt, B.; Schneider, O.; Schopper, A.; Schubiger, M.; Schune, M.-H.; Schwemmer, R.; Sciascia, B.; Sciubba, A.; Semennikov, A.; Serra, N.; Serrano, J.; Sestini, L.; Seyfert, P.; Shapkin, M.; Shapoval, I.; Shcheglov, Y.; Shears, T.; Shekhtman, L.; Shevchenko, V.; Shires, A.; Siddi, B. G.; Silva Coutinho, R.; Silva de Oliveira, L.; Simi, G.; Sirendi, M.; Skidmore, N.; Skwarnicki, T.; Smith, E.; Smith, E.; Smith, I. T.; Smith, J.; Smith, M.; Snoek, H.; Sokoloff, M. D.; Soler, F. J. P.; Soomro, F.; Souza, D.; Souza De Paula, B.; Spaan, B.; Spradlin, P.; Sridharan, S.; Stagni, F.; Stahl, M.; Stahl, S.; Steinkamp, O.; Stenyakin, O.; Sterpka, F.; Stevenson, S.; Stoica, S.; Stone, S.; Storaci, B.; Stracka, S.; Straticiuc, M.; Straumann, U.; Sun, L.; Sutcliffe, W.; Swientek, K.; Swientek, S.; Syropoulos, V.; Szczekowski, M.; Szczypka, P.; Szumlak, T.; T'Jampens, S.; Tayduganov, A.; Tekampe, T.; Teklishyn, M.; Tellarini, G.; Teubert, F.; Thomas, C.; Thomas, E.; van Tilburg, J.; Tisserand, V.; Tobin, M.; Todd, J.; Tolk, S.; Tomassetti, L.; Tonelli, D.; Topp-Joergensen, S.; Torr, N.; Tournefier, E.; Tourneur, S.; Trabelsi, K.; Tran, M. T.; Tresch, M.; Trisovic, A.; Tsaregorodtsev, A.; Tsopelas, P.; Tuning, N.; Ukleja, A.; Ustyuzhanin, A.; Uwer, U.; Vacca, C.; Vagnoni, V.; Valenti, G.; Vallier, A.; Vazquez Gomez, R.; Vazquez Regueiro, P.; Vázquez Sierra, C.; Vecchi, S.; Velthuis, J. J.; Veltri, M.; Veneziano, G.; Vesterinen, M.; Viaud, B.; Vieira, D.; Vieites Diaz, M.; Vilasis-Cardona, X.; Volkov, V.; Vollhardt, A.; Volyanskyy, D.; Voong, D.; Vorobyev, A.; Vorobyev, V.; Voß, C.; de Vries, J. A.; Waldi, R.; Wallace, C.; Wallace, R.; Walsh, J.; Wandernoth, S.; Wang, J.; Ward, D. R.; Watson, N. K.; Websdale, D.; Weiden, A.; Whitehead, M.; Wilkinson, G.; Wilkinson, M.; Williams, M.; Williams, M. P.; Williams, M.; Williams, T.; Wilson, F. F.; Wimberley, J.; Wishahi, J.; Wislicki, W.; Witek, M.; Wormser, G.; Wotton, S. A.; Wright, S.; Wyllie, K.; Xie, Y.; Xu, Z.; Yang, Z.; Yu, J.; Yuan, X.; Yushchenko, O.; Zangoli, M.; Zavertyaev, M.; Zhang, L.; Zhang, Y.; Zhelezov, A.; Zhokhov, A.; Zhong, L.; Zucchelli, S.; LHCb Collaboration

2016-03-01

Amplitude models are applied to studies of resonance structure in D0→KS0K-π+ and D0→KS0K+π- decays using p p collision data corresponding to an integrated luminosity of 3.0 fb-1 collected by the LHCb experiment. Relative magnitude and phase information is determined, and coherence factors and related observables are computed for both the whole phase space and a restricted region of 100 MeV /c2 around the K*(892 )± resonance. Two formulations for the K π S -wave are used, both of which give a good description of the data. The ratio of branching fractions B (D0→KS0K+π- )/B (D0→KS0K-π+ ) is measured to be 0.655 ±0.004 (stat ) ±0.006 (syst ) over the full phase space and 0.370 ±0.003 (stat ) ±0.012 (syst ) in the restricted region. A search for C P violation is performed using the amplitude models and no significant effect is found. Predictions from SU(3) flavor symmetry for K*(892 ) K amplitudes of different charges are compared with the amplitude model results.

RhoA orchestrates glycolysis for Th2 cell differentiation and allergic airway inflammation

PubMed Central

Yang, Jun-Qi; Kalim, Khalid W.; Li, Yuan; Zhang, Shuangmin; Hinge, Ashwini; Filippi, Marie-Dominique; Zheng, Yi; Guo, Fukun

2015-01-01

Background Mitochondrial metabolism is known to be important for T cell activation. However, its involvement in effector T cell differentiation has just begun to gain attention. Importantly, how metabolic pathways are integrated with T cell activation and effector cell differentiation and function remains largely unknown. Objective We sought to test our hypothesis that RhoA GTPase orchestrates glycolysis for Th2 cell differentiation and Th2-mediated allergic airway inflammation. Methods Conditional RhoA-deficient mice were generated by crossing RhoAflox/flox mice with CD2-Cre transgenic mice. Effects of RhoA on Th2 differentiation were evaluated by in vitro Th2-polarized culture conditions, and in vivo in ovalbumin (OVA)-induced allergic airway inflammation. Cytokines were measured by intracellular staining and ELISA. T cell metabolism was measured by Seahorse XF24 Analyzer and flow cytometry. Results Disruption of RhoA inhibited T cell activation and Th2 differentiation in vitro and prevented the development of allergic airway inflammation in vivo, with no effect on Th1 cells. RhoA deficiency in activated T cells led to multiple defects in metabolic pathways such as glycolysis and oxidative phosphorylation. Importantly, RhoA couples glycolysis to Th2 cell differentiation and allergic airway inflammation via regulating IL-4 receptor mRNA expression and Th2-specific signaling events. Finally, inhibition of Rho-associated protein kinase (ROCK), an immediate downstream effector of RhoA, blocked Th2 differentiation and allergic airway inflammation. Conclusion RhoA is a key component of the signaling cascades leading to Th2-differentiation and allergic airway inflammation, at least in part, through the control of T cell metabolism and via ROCK pathway. PMID:26100081

NMR characterization of weak interactions between RhoGDI2 and fragment screening hits.

PubMed

Liu, Jiuyang; Gao, Jia; Li, Fudong; Ma, Rongsheng; Wei, Qingtao; Wang, Aidong; Wu, Jihui; Ruan, Ke

2017-01-01

The delineation of intrinsically weak interactions between novel targets and fragment screening hits has long limited the pace of hit-to-lead evolution. Rho guanine-nucleotide dissociation inhibitor 2 (RhoGDI2) is a novel target that lacks any chemical probes for the treatment of tumor metastasis. Protein-observed and ligand-observed NMR spectroscopy was used to characterize the weak interactions between RhoGDI2 and fragment screening hits. We identified three hits of RhoGDI2 using streamlined NMR fragment-based screening. The binding site residues were assigned using non-uniformly sampled C α - and H α -based three dimensional NMR spectra. The molecular docking to the proposed geranylgeranyl binding pocket of RhoGDI2 was guided by NMR restraints of chemical shift perturbations and ligand-observed transferred paramagnetic relaxation enhancement. We further validated the weak RhoGDI2-hit interactions using mutagenesis and structure-affinity analysis. Weak interactions between RhoGDI2 and fragment screening hits were delineated using an integrated NMR approach. Binders to RhoGDI2 as a potential anti-cancer target have been first reported, and their weak interactions were depicted using NMR spectroscopy. Our work highlights the powerfulness and the versatility of the integrative NMR techniques to provide valuable structural insight into the intrinsically weak interactions between RhoGDI2 and the fragment screening hits, which could hardly be conceived using other biochemical techniques. Copyright © 2016 Elsevier B.V. All rights reserved.

Progression of Human Renal Cell Carcinoma via Inhibition of RhoA-ROCK Axis by PARG1.

PubMed

Miyazaki, Junichiro; Ito, Keiichi; Fujita, Tomonobu; Matsuzaki, Yuriko; Asano, Takako; Hayakawa, Masamichi; Asano, Tomohiko; Kawakami, Yutaka

2017-04-01

Renal cell carcinoma (RCC) is the most lethal urological malignancy with high risk of recurrence; thus, new prognostic biomarkers are needed. In this study, a new RCC antigen, PTPL1 associated RhoGAP1 (PARG1), was identified by using serological identification of recombinant cDNA expression cloning with sera from RCC patients. PARG1 protein was found to be differentially expressed in RCC cells among patients. High PARG1 expression is significantly correlated with various clinicopathological factors relating to cancer cell proliferation and invasion, including G3 percentage (P = .0046), Ki-67 score (p expression is also correlated with high recurrence of N0M0 patients (P = .0084) and poor prognosis in RCC patients (P = .0345). Multivariate analysis has revealed that high PARG1 expression is an independent factor for recurrence (P = .0149) of N0M0 RCC patients. In in vitro studies, depletion of PARG1by siRNA in human RCC cell lines inhibited their proliferation through inducing G1 cell cycle arrest via upregulation of p53 and subsequent p21 Cip1/Waf1 , which are mediated by increased RhoA-ROCK activities. Similarly, PARG1 depletion cells inhibited invasion ability via increasing RhoA-ROCK activities in the RCC cell lines. Conversely, overexpression of PARG1 on human embryonic kidney cell line HEK293T promotes its cell proliferation and invasion. These results indicate that PARG1 plays crucial roles in progression of human RCC in increasing cell proliferation and invasion ability via inhibition of the RhoA-ROCK axis, and PARG1 is a poor prognostic marker, particularly for high recurrence of N0M0 RCC patients. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

Accurate and reproducible measurements of RhoA activation in small samples of primary cells.

PubMed

Nini, Lylia; Dagnino, Lina

2010-03-01

Rho GTPase activation is essential in a wide variety of cellular processes. Measurement of Rho GTPase activation is difficult with limited material, such as tissues or primary cells that exhibit stringent culture requirements for growth and survival. We defined parameters to accurately and reproducibly measure RhoA activation (i.e., RhoA-GTP) in cultured primary keratinocytes in response to serum and growth factor stimulation using enzyme-linked immunosorbent assay (ELISA)-based G-LISA assays. We also established conditions that minimize RhoA-GTP in unstimulated cells without affecting viability, allowing accurate measurements of RhoA activation on stimulation or induction of exogenous GTPase expression. Copyright 2009 Elsevier Inc. All rights reserved.

New physics in resonant production of Higgs boson pairs.

PubMed

Barger, Vernon; Everett, Lisa L; Jackson, C B; Peterson, Andrea D; Shaughnessy, Gabe

2015-01-09

We advocate a search for an extended scalar sector at the LHC via hh production, where h is the 125 GeV Higgs boson. A resonance feature in the hh invariant mass is a smoking gun of an s-channel heavy Higgs resonance, H. With one h decaying to two photons and the other decaying to b quarks, the resonant signal may be discoverable above the hh continuum background for M(H)<1  TeV. The product of the scalar and top Yukawa couplings can be measured to better than 10%-20% accuracy, and its sign can be inferred from the hh line shape via interference effects.

Tumor Metabolism and Perfusion in Head and Neck Squamous Cell Carcinoma: Pretreatment Multimodality Imaging With {sup 1}H Magnetic Resonance Spectroscopy, Dynamic Contrast-Enhanced MRI, and [{sup 18}F]FDG-PET

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

Jansen, Jacobus F.A.; Department of Radiology, Memorial Sloan-Kettering Cancer Center, New York, New York; Department of Radiology, Maastricht University Medical Center, Maastricht

2012-01-01

Purpose: To correlate proton magnetic resonance spectroscopy ({sup 1}H-MRS), dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI), and {sup 18}F-labeled fluorodeoxyglucose positron emission tomography ([{sup 18}F]FDG PET) of nodal metastases in patients with head and neck squamous cell carcinoma (HNSCC) for assessment of tumor biology. Additionally, pretreatment multimodality imaging was evaluated for its efficacy in predicting short-term response to treatment. Methods and Materials: Metastatic neck nodes were imaged with {sup 1}H-MRS, DCE-MRI, and [{sup 18}F]FDG PET in 16 patients with newly diagnosed HNSCC, before treatment. Short-term patient radiological response was evaluated at 3 to 4 months. Correlations among {sup 1}H-MRS (choline concentrationmore » relative to water [Cho/W]), DCE-MRI (volume transfer constant [K{sup trans}]; volume fraction of the extravascular extracellular space [v{sub e}]; and redistribution rate constant [k{sub ep}]), and [{sup 18}F]FDG PET (standard uptake value [SUV] and total lesion glycolysis [TLG]) were calculated using nonparametric Spearman rank correlation. To predict short-term responses, logistic regression analysis was performed. Results: A significant positive correlation was found between Cho/W and TLG ({rho} = 0.599; p = 0.031). Cho/W correlated negatively with heterogeneity measures of standard deviation std(v{sub e}) ({rho} = -0.691; p = 0.004) and std(k{sub ep}) ({rho} = -0.704; p = 0.003). Maximum SUV (SUVmax) values correlated strongly with MRI tumor volume ({rho} = 0.643; p = 0.007). Logistic regression indicated that std(K{sup trans}) and SUVmean were significant predictors of short-term response (p < 0.07). Conclusion: Pretreatment multimodality imaging using {sup 1}H-MRS, DCE-MRI, and [{sup 18}F]FDG PET is feasible in HNSCC patients with nodal metastases. Additionally, combined DCE-MRI and [{sup 18}F]FDG PET parameters were predictive of short-term response to treatment.« less

Abnormal Activation of RhoA/ROCK-I Signaling in Junctional Zone Smooth Muscle Cells of Patients With Adenomyosis.

PubMed

Wang, S; Duan, H; Zhang, Y; Sun, F Q

2016-03-01

Adenomyosis (ADS) is a common estrogen-dependent gynecological disease with unknown etiology. The RhoA/Rho-kinase (ROCK) signaling pathway is involved in various cellular functions, including migration, proliferation, and smooth muscle contraction. Here we examined the potential role of this pathway in junctional zone (JZ) contraction in women with and without ADS. We demonstrated that in the normal JZ, RhoA and ROCK-I messenger RNA (mRNA) and protein expression was significantly higher in the proliferative phase of the menstrual cycle than in the secretory phase. Expression of RhoA and ROCK-I in the JZ from women with ADS was significantly higher than in the control women and showed no significant differences across the menstrual cycle. Treatment of JZ smooth muscle cells (JZSMCs) with estrogen at 0, 1, 10, or 100 nmol/L for 24 hours resulted in increased expression of RhoA, ROCK-I, and myosin light-chain (MLC) phosphorylation (p-MLC) in a dose-dependent manner. In parallel to its effects on p-MLC, estrogen-mediated, dose-dependent contraction responses in JZSMCs. Estrogen-mediated contraction in the ADS group was significantly higher than in the controls and also showed no significant differences across the menstrual cycle. These effects were suppressed in the presence of ICI 182780 or Y27632, supporting an estrogen receptor-dependent and RhoA activation-dependent mechanism. Our results indicate that the level of RhoA and ROCK-I increases in patients with ADS and the cyclic change is lost. Estrogen may affect uterine JZ contraction of ADS by enhancing RhoA/ ROCK-I signaling. © The Author(s) 2015.

Involvement of rho-gtpases in fibroblast adhesion and fibronectine fibrillogenesis under stretch

NASA Astrophysics Data System (ADS)

Guignandon, A.; Lambert, C.; Rattner, A.; Servotte, S.; Lapiere, C.; Nusgens, B.; Vico, L.

The Rho family small GTPases play a crucial role in mediating cellular adaptation to mechanical stimulation (MS), and possibly to microgravity (μg), through effects on the cytoskeleton and cell adhesion which is, in turn, mainly regulated by fibronectin fibrillogenesis (FnF). It remains unclear how mechanical stimulation is transduced to the Rho signaling pathways and how it impacts on fibronectin (fbn) fibrillogenesis (FnF). μg (2 days, mission STS-095) led to de-adhesion of fibroblasts and modification of the underlying extracellular matrix. To determine whether GTPases modulated FnF, we generated stable cell lines expressing high level of activated RhoA and Rac1 (QL) as compared to wild type (WI26-WT). After MS application [8% deformation, 1Hz, 15 min., 3 times/day for 1-2 days], we quantified focal adhesion (vinculin, paxillin, FAKY397), f-actin stress fibers (Sf) and FnF with home-developed softwares. We reported that after MS, Sf are more rapidly (30min) formed under the nucleus in Wi26-WT (+100%) and Rac1 (+200%) than in RhoA (+20%). Vinculin & paxillin were only restricted to the cell edge in static conditions and homogeneously distributed after MS in WT and Rac1. The relative area of contacts (vinculin & paxillin) was more dramatically enhanced by MS in Rac1 (+80%) than in WT (+40%) and RhoA (+25%) indicating that new focal contacts are formed under MS and supported the presence of Sf. MS Activation of FAK (FAKY397) was clear in WT and Rac1 and reduced in RhoA. FnF was restricted to cell-cell contacts zone without any change in the relative area of fbn after a 2-days MS. However we found more numerous spots of fbn at the cell center in Rac1 as compared with RhoA & WT suggesting that these fibrillar contacts will grow upon maturation and modulate FnF. The results indicate that MS induces formation of Sf and focal adhesions and enhances FF. RhoA has been shown to induce the formation of Sf and focal adhesions, and Rac1 activation decreases Rho activity in

Pion decay constant and the {rho}-meson mass at finite temperature in hidden local symmetry

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

Harada, M.; Shibata, A.

1997-06-01

We study the temperature dependence of the pion decay constant and {rho}-meson mass in the hidden local symmetry model at one loop. Using the standard imaginary time formalism, we include the thermal effect of the {rho} meson as well as that of the pion. We show that the pion gives a dominant contribution to the pion decay constant and the {rho}-meson contribution slightly decreases the critical temperature. The {rho}-meson pole mass increases as T{sup 4}/m{sub {rho}}{sup 2} at low temperature, dominated by the pion-loop effect. At high temperature, although the pion-loop effect decreases the {rho}-meson mass, the {rho}-loop contribution overcomesmore » the pion-loop contribution and the {rho}-meson mass increases with temperature. We also show that the conventional parameter a is stable as the temperature increases. {copyright} {ital 1997} {ital The American Physical Society}« less

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

PubMed Central

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

2015-01-01

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

Angular momentum content of the rho meson in lattice QCD.

PubMed

Glozman, Leonid Ya; Lang, C B; Limmer, Markus

2009-09-18

The variational method allows one to study the mixing of interpolators with different chiral transformation properties in the nonperturbatively determined physical state. It is then possible to define and calculate in a gauge-invariant manner the chiral as well as the partial wave content of the quark-antiquark component of a meson in the infrared, where mass is generated. Using a unitary transformation from the chiral basis to the ;{2S+1}L_{J} basis one may extract a partial wave content of a meson. We present results for the ground state of the rho meson using quenched simulations as well as simulations with n_{f} = 2 dynamical quarks, all for lattice spacings close to 0.15 fm. We point out that these results indicate a simple ;{3}S_{1}-wave composition of the rho meson in the infrared, like in the SU(6) flavor-spin quark model.

An empirical model to determine the hadronic resonance contributions \\overline{B}{} ^0 → \\overline{K}{} ^{*0} μ ^+ μ ^- to transitions

NASA Astrophysics Data System (ADS)

Blake, T.; Egede, U.; Owen, P.; Petridis, K. A.; Pomery, G.

2018-06-01

A method for analysing the hadronic resonance contributions in \\overline{B}{} ^0 → \\overline{K}{} ^{*0} μ ^+ μ ^- decays is presented. This method uses an empirical model that relies on measurements of the branching fractions and polarisation amplitudes of final states involving J^{PC}=1^{-} resonances, relative to the short-distance component, across the full dimuon mass spectrum of \\overline{B}{} ^0 → \\overline{K}{} ^{*0} μ ^+ μ ^- transitions. The model is in good agreement with existing calculations of hadronic non-local effects. The effect of this contribution to the angular observables is presented and it is demonstrated how the narrow resonances in the q^2 spectrum provide a dramatic enhancement to CP-violating effects in the short-distance amplitude. Finally, a study of the hadronic resonance effects on lepton universality ratios, R_{K^{(*)}}, in the presence of new physics is presented.

Rho-kinase inhibition acutely augments blood flow in focal cerebral ischemia via endothelial mechanisms.

PubMed

Shin, Hwa Kyoung; Salomone, Salvatore; Potts, E Michelle; Lee, Sae-Won; Millican, Eric; Noma, Kensuke; Huang, Paul L; Boas, David A; Liao, James K; Moskowitz, Michael A; Ayata, Cenk

2007-05-01

Rho-kinase is a serine threonine kinase that increases vasomotor tone via its effects on both endothelium and smooth muscle. Rho-kinase inhibition reduces cerebral infarct size in wild type, but not endothelial nitric oxide synthase deficient (eNOS-/-) mice. The mechanism may be related to Rho-kinase activation under hypoxic/ischemic conditions and impaired vasodilation because of downregulation of eNOS activity. To further implicate Rho-kinase in impaired vascular relaxation during hypoxia/ischemia, we exposed isolated vessels from rat and mouse to 60 mins of hypoxia, and showed that hypoxia reversibly abolished acetylcholine-induced eNOS-dependent relaxation, and that Rho-kinase inhibitor hydroxyfasudil partially preserved this relaxation during hypoxia. We, therefore, hypothesized that if hypoxia-induced Rho-kinase activation acutely impairs vasodilation in ischemic cortex, in vivo, then Rho-kinase inhibitors would acutely augment cerebral blood flow (CBF) as a mechanism by which they reduce infarct size. To test this, we studied the acute cerebral hemodynamic effects of Rho-kinase inhibitors in ischemic core and penumbra during distal middle cerebral artery occlusion (dMCAO) in wild-type and eNOS-/- mice using laser speckle flowmetry. When administered 60 mins before or immediately after dMCAO, Rho-kinase inhibitors hydroxyfasudil and Y-27632 reduced the area of severely ischemic cortex. However, hydroxyfasudil did not reduce the area of CBF deficit in eNOS-/- mice, suggesting that its effect on CBF within the ischemic cortex is primarily endothelium-dependent, and not mediated by its direct vasodilator effect on vascular smooth muscle. Our results suggest that Rho-kinase negatively regulates eNOS activity in acutely ischemic brain, thereby worsening the CBF deficit. Therefore, rapid nontranscriptional upregulation of eNOS activity by small molecule inhibitors of Rho-kinase may be a viable therapeutic approach in acute stroke.

Small Rho GTPases and Cholesterol Biosynthetic Pathway Intermediates in African Swine Fever Virus Infection

PubMed Central

Quetglas, Jose I.; Hernáez, Bruno; Galindo, Inmaculada; Muñoz-Moreno, Raquel; Cuesta-Geijo, Miguel A.

2012-01-01

The integrity of the cholesterol biosynthesis pathway is required for efficient African swine fever virus (ASFV) infection. Incorporation of prenyl groups into Rho GTPases plays a key role in several stages of ASFV infection, since both geranylgeranyl and farnesyl pyrophosphates are required at different infection steps. We found that Rho GTPase inhibition impaired virus morphogenesis and resulted in an abnormal viral factory size with the accumulation of envelope precursors and immature virions. Furthermore, abundant defective virions reached the plasma membrane, and filopodia formation in exocytosis was abrogated. Rac1 was activated at early ASFV infection stages, coincident with microtubule acetylation, a process that stabilizes microtubules for virus transport. Rac1 inhibition did not affect the viral entry step itself but impaired subsequent virus production. We found that specific Rac1 inhibition impaired viral induced microtubule acetylation and viral intracellular transport. These findings highlight that viral infection is the result of a carefully orchestrated modulation of Rho family GTPase activity within the host cell; this modulation results critical for virus morphogenesis and in turn, triggers cytoskeleton remodeling, such as microtubule stabilization for viral transport during early infection. PMID:22114329

Granzyme B of cytotoxic T cells induces extramitochondrial reactive oxygen species production via caspase-dependent NADPH oxidase activation.

PubMed

Aguiló, Juan I; Anel, Alberto; Catalán, Elena; Sebastián, Alvaro; Acín-Pérez, Rebeca; Naval, Javier; Wallich, Reinhard; Simon, Markus M; Pardo, Julián

2010-07-01

Induction of reactive oxygen species (ROS) is a hallmark of granzyme B (gzmB)-mediated pro-apoptotic processes and target cell death. However, it is unclear to what extent the generated ROS derive from mitochondrial and/or extra-mitochondrial sources. To clarify this point, we have produced a mutant EL4 cell line, termed EL4-rho(0), which lacks mitochondrial DNA, associated with a decreased mitochondrial membrane potential and a defective ROS production through the electron transport chain of oxidative phosphorylation. When incubated with either recombinant gzmB plus streptolysin or ex vivo gzmB(+) cytotoxic T cells, EL4-rho(0) cells showed phosphatydylserine translocation, caspase 3 activation, Bak conformational change, cytochrome c release and apoptotic morphology comparable to EL4 cells. Moreover, EL4-rho(0) cells produced ROS at levels similar to EL4 under these conditions. GzmB-mediated ROS production was almost totally abolished in both cell lines by the pan-caspase inhibitor, Z-VAD-fmk. However, addition of apocynin, a specific inhibitor of nicotinamide adenine dinucleotide phosphate (NADPH) oxidases, led to a significant reduction of ROS production and cell death only in EL4-rho(0) but not EL4 cells. These data suggest that gzmB-induced cell death is accompanied by a caspase-dependent pathway of extra-mitochondrial ROS production, most probably through activation of NADPH oxidase.

Spin Wave Resonances in La_0.67Ba_0.33MnO_3

NASA Astrophysics Data System (ADS)

Lofland, S. E.; Dominguez, M.; Tyagi, S. D.; Bhagat, S. M.; Kwon, C.; Robson, M. C.; Sharma, R. P.; Ramesh, R.; Venkatesan, T.

1996-03-01

Thin ( ~ 110 nm thick) films of La_0.67Ba_0.33MnO3 (LBMO) were prepared by pulsed laser deposition on LaAlO3 substrates. Some films were grown directly onto LaAlO3 while other films were made by first creating a ~ 80 nm thick buffer layer of SrTiO3 (STO) and then capped with a 20 nm thick layer of STO. X-ray and RBS measurements showed the films to be of high crystalline quality. Film thickness was determined by RBS. Spin wave resonance (SWR) measurements were performed at both 10 and 36 GHz. In both types of films Portis (equally spaced) modes were observed. This indicated a non-uniform magnetization which has a parabolic spatial distribution. However, certain tri-layer films showed Kittel modes which follow the n^2 dependence of the mode number n on the resonance field. From the mode separation and the thickness, we calculate the spin stiffness D(0) to be 47 ± 10 meVÅWith this value of D and the magnetization M, we estimate a spatial variation of the magnetization of ~ 20% for those films which showed Portis modes.

Differential effects of Rho GTPases on axonal and dendritic development in hippocampal neurones.

PubMed

Ahnert-Hilger, G; Höltje, M; Grosse, G; Pickert, G; Mucke, C; Nixdorf-Bergweiler, B; Boquet, P; Hofmann, F; Just, I

2004-07-01

Formation of neurites and their differentiation into axons and dendrites requires precisely controlled changes in the cytoskeleton. While small GTPases of the Rho family appear to be involved in this regulation, it is still unclear how Rho function affects axonal and dendritic growth during development. Using hippocampal neurones at defined states of differentiation, we have dissected the function of RhoA in axonal and dendritic growth. Expression of a dominant negative RhoA variant inhibited axonal growth, whereas dendritic growth was promoted. The opposite phenotype was observed when a constitutively active RhoA variant was expressed. Inactivation of Rho by C3-catalysed ADP-ribosylation using C3 isoforms (Clostridium limosum, C3(lim) or Staphylococcus aureus, C3(stau2)), diminished axonal branching. By contrast, extracellularly applied nanomolar concentrations of C3 from C. botulinum (C3(bot)) or enzymatically dead C3(bot) significantly increased axon growth and axon branching. Taken together, axonal development requires activation of RhoA, whereas dendritic development benefits from its inactivation. However, extracellular application of enzymatically active or dead C3(bot) exclusively promotes axonal growth and branching suggesting a novel neurotrophic function of C3 that is independent from its enzymatic activity.

Microfilament regulatory protein MENA increases activity of RhoA and promotes metastasis of hepatocellular carcinoma.

PubMed

Lin, Ling; Yang, Xiao-Mei; Li, Jun; Zhang, Yan-Li; Qin, Wenxin; Zhang, Zhi-Gang

2014-09-10

Mammalian enabled (MENA), usually known as a direct regulator of microfilament polymerization and bundling, promotes metastasis in various cancers. Here we focus on the role of MENA in hepatocellular carcinoma (HCC) metastasis and the relevant mechanism from the view of RhoA activity regulation. By HCC tissue microarray analysis, we found that MENA expression was positively associated with satellite lesions (P<0.01) and vascular invasion (P<0.01). Cases with membrane reinforcement of MENA staining in HCC tissues had significantly higher rates of early recurrence in the intermediate MENA expression group. Knockdown of MENA significantly suppressed HCC cell migration and invasion in vitro, as well as their intrahepatic and distant metastasis in vivo. Knockdown of MENA also decreased filopodia and stress fibers in SMMC-7721 cells. Furthermore, a decrease of RhoA activity was detected by a pull-down assay in SMMC-7721-shMENA cells. The ROCK inhibitor, Y-27632, suppressed migration of both MENA knockdown SMMC-7721 cells and control cells, but diminished their difference. Thus, our findings suggest that MENA promotes HCC cell motility by activating RhoA. Copyright © 2014 Elsevier Inc. All rights reserved.

Rotation in USco and rho Oph with K2

NASA Astrophysics Data System (ADS)

Rebull, Luisa; Stauffer, John; K2 Clusters Team

2018-01-01

K2 observed Upper Scorpius and rho Oph as part of their Campaign 2 in 2014. At ~8 and ~1 Myr respectively, the stars in Upper Sco and rho Oph exhibit greater diversity of light curve shapes than are found in older clusters observed with K2 such as Pleiades or Praesepe. Nonetheless, we are able to derive rotation periods for 85% (971/1136) of the USco members and 80% (71/88) of the rho Oph members. About 25% of the periodic stars have evidence for multiple periods. These light curves sample smaller amplitudes to lower masses and with a far better cadence, than has even been probed before. We can compare USco with similar stars in Praesepe (~700 Myr) and the Pleiades (~125 Myr), all with K2 light curves.

The proteinase-activated receptor-2 mediates phagocytosis in a Rho-dependent manner in human keratinocytes.

PubMed

Scott, Glynis; Leopardi, Sonya; Parker, Lorelle; Babiarz, Laura; Seiberg, Miri; Han, Rujiing

2003-09-01

Recent work shows that the G-protein-coupled receptor proteinase activated receptor-2 activates signals that stimulate melanosome uptake in keratinocytes in vivo and in vitro. The Rho family of GTP-binding proteins is involved in cytoskeletal remodeling during phagocytosis. We show that proteinase-activated receptor-2 mediated phagocytosis in human keratinocytes is Rho dependent and that proteinase-activated receptor-2 signals to activate Rho. In contrast, Rho activity did not affect either proteinase-activated receptor-2 activity or mRNA and protein levels. We explored the signaling mechanisms of proteinase-activated receptor-2 mediated Rho activation in human keratinocytes and show that activation of proteinase-activated receptor-2, either through specific proteinase-activated receptor-2 activating peptides or through trypsinization, elevates cAMP in keratinocytes. Proteinase-activated receptor-2 mediated Rho activation was pertussis toxin insensitive and independent of the protein kinase A signaling pathway. These data are the first to show that proteinase-activated receptor-2 mediated phagocytosis is Rho dependent and that proteinase-activated receptor-2 signals to Rho and cAMP in keratinocytes. Because phagocytosis of melanosomes is recognized as an important mechanism for melanosome transfer to keratinocytes, these results suggest that Rho is a critical signaling intermediate in melanosome uptake in keratinocytes.

RhoA/ROCK Signaling Pathway Mediates Shuanghuanglian Injection-Induced Pseudo-allergic Reactions.

PubMed

Han, Jiayin; Zhao, Yong; Zhang, Yushi; Li, Chunying; Yi, Yan; Pan, Chen; Tian, Jingzhuo; Yang, Yifei; Cui, Hongyu; Wang, Lianmei; Liu, Suyan; Liu, Jing; Deng, Nuo; Liang, Aihua

2018-01-01

Background: Shuanghuanglian injection (SHLI) is a famous Chinese medicine used as an intravenous preparation for the treatment of acute respiratory tract infections. In the recent years, the immediate hypersensitivity reactions induced by SHLI have attracted broad attention. However, the mechanism involved in these reactions has not yet been elucidated. The present study aims to explore the characteristics of the immediate hypersensitivity reactions induced by SHLI and deciphers the role of the RhoA/ROCK signaling pathway in these reactions. Methods: SHLI-immunized mice or naive mice were intravenously injected (i.v.) with SHLI (600 mg/kg) once, and vascular leakage in the ears was evaluated. Passive cutaneous anaphylaxis test was conducted using sera collected from SHLI-immunized mice. Naive mice were administered (i.v.) with a single dose of 150, 300, or 600 mg/kg of SHLI, and vascular leakage, histamine release, and histopathological alterations in the ears, lungs, and intestines were tested. In vitro , human umbilical vein endothelial cell (HUVEC) monolayer was incubated with SHLI (0.05, 0.1, or 0.15 mg/mL), and the changes in endothelial permeability and cytoskeleton were observed. Western blot analysis was performed and ROCK inhibitor was employed to investigate the contribution of the RhoA/ROCK signaling pathway in SHLI-induced hypersensitivity reactions, both in HUVECs and in mice. Results: Our results indicate that SHLI was able to cause immediate dose-dependent vascular leakage, edema, and exudates in the ears, lungs, and intestines, and histamine release in mice. These were pseudo-allergic reactions, as SHLI-specific IgE was not elicited during sensitization. In addition, SHLI induced reorganization of actin cytoskeleton and disrupted the endothelial barrier. The administration of SHLI directly activated the RhoA/ROCK signaling pathway both in HUVECs and in the ears, lungs, and intestines of mice. Fasudil hydrochloride, a ROCK inhibitor, ameliorated the

RhoA/ROCK Signaling Pathway Mediates Shuanghuanglian Injection-Induced Pseudo-allergic Reactions

PubMed Central

Han, Jiayin; Zhao, Yong; Zhang, Yushi; Li, Chunying; Yi, Yan; Pan, Chen; Tian, Jingzhuo; Yang, Yifei; Cui, Hongyu; Wang, Lianmei; Liu, Suyan; Liu, Jing; Deng, Nuo; Liang, Aihua

2018-01-01

Background: Shuanghuanglian injection (SHLI) is a famous Chinese medicine used as an intravenous preparation for the treatment of acute respiratory tract infections. In the recent years, the immediate hypersensitivity reactions induced by SHLI have attracted broad attention. However, the mechanism involved in these reactions has not yet been elucidated. The present study aims to explore the characteristics of the immediate hypersensitivity reactions induced by SHLI and deciphers the role of the RhoA/ROCK signaling pathway in these reactions. Methods: SHLI-immunized mice or naive mice were intravenously injected (i.v.) with SHLI (600 mg/kg) once, and vascular leakage in the ears was evaluated. Passive cutaneous anaphylaxis test was conducted using sera collected from SHLI-immunized mice. Naive mice were administered (i.v.) with a single dose of 150, 300, or 600 mg/kg of SHLI, and vascular leakage, histamine release, and histopathological alterations in the ears, lungs, and intestines were tested. In vitro, human umbilical vein endothelial cell (HUVEC) monolayer was incubated with SHLI (0.05, 0.1, or 0.15 mg/mL), and the changes in endothelial permeability and cytoskeleton were observed. Western blot analysis was performed and ROCK inhibitor was employed to investigate the contribution of the RhoA/ROCK signaling pathway in SHLI-induced hypersensitivity reactions, both in HUVECs and in mice. Results: Our results indicate that SHLI was able to cause immediate dose-dependent vascular leakage, edema, and exudates in the ears, lungs, and intestines, and histamine release in mice. These were pseudo-allergic reactions, as SHLI-specific IgE was not elicited during sensitization. In addition, SHLI induced reorganization of actin cytoskeleton and disrupted the endothelial barrier. The administration of SHLI directly activated the RhoA/ROCK signaling pathway both in HUVECs and in the ears, lungs, and intestines of mice. Fasudil hydrochloride, a ROCK inhibitor, ameliorated the

Resonance Production in Heavy-Ion Collisions

NASA Astrophysics Data System (ADS)

Knospe, Anders G.

2018-02-01

Hadronic resonances are unique probes that allow the properties of heavyion collisions to be studied. Topics that can be studied include modification of spectral shapes, in-medium energy loss of parsons, vector-meson spin alignment, hydrodynamic flow, recombination, strangeness production, and the properties of the hadronic phase. Measurements of resonances in p+p, p+A, and d+A collisions serve as baselines for heavy-ion studies and also permit searches for possible collective effects in these smaller systems. These proceedings present a selection of results related to these topics from experiments at RHIC, LHC, and other facilities, as well as comparisons to theoretical models.

DNA topoisomerase IIβ stimulates neurite outgrowth in neural differentiated human mesenchymal stem cells through regulation of Rho-GTPases (RhoA/Rock2 pathway) and Nurr1 expression.

PubMed

Zaim, Merve; Isik, Sevim

2018-04-25

DNA topoisomerase IIβ (topo IIβ) is known to regulate neural differentiation by inducing the neuronal genes responsible for critical neural differentiation events such as neurite outgrowth and axon guidance. However, the pathways of axon growth controlled by topo IIβ have not been clarified yet. Microarray results of our previous study have shown that topo IIβ silencing in neural differentiated primary human mesenchymal stem cells (hMSCs) significantly alters the expression pattern of genes involved in neural polarity, axonal growth, and guidance, including Rho-GTPases. This study aims to further analyze the regulatory role of topo IIβ on the process of axon growth via regulation of Rho-GTPases. For this purpose, topo IIβ was silenced in neurally differentiated hMSCs. Cells lost their morphology because of topo IIβ deficiency, becoming enlarged and flattened. Additionally, a reduction in both neural differentiation efficiency and neurite length, upregulation in RhoA and Rock2, downregulation in Cdc42 gene expression were detected. On the other hand, cells were transfected with topo IIβ gene to elucidate the possible neuroprotective effect of topo IIβ overexpression on neural-induced hMSCs. Topo IIβ overexpression prompted all the cells to exhibit neural cell morphology as characterized by longer neurites. RhoA and Rock2 expressions were downregulated, whereas Cdc42 expression was upregulated. Nurr1 expression level correlated with topo IIβ in both topo IIβ-overexpressed and -silenced cells. Furthermore, differential translocation of Rho-GTPases was detected by immunostaining in response to topo IIβ. Our results suggest that topo IIβ deficiency could give rise to neurodegeneration through dysregulation of Rho-GTPases. However, further in-vivo research is needed to demonstrate if re-regulation of Rho GTPases by topo IIβ overexpression could be a neuroprotective treatment in the case of neurodegenerative diseases.

The amino acid motif L/IIxxFE defines a novel actin-binding sequence in PDZ-RhoGEF

PubMed Central

Banerjee, Jayashree; Fischer, Christopher C.; Wedegaertner, Philip B.

2009-01-01

PDZ-RhoGEF is a member of the regulator of G protein signaling (RGS) domain-containing RhoGEFs (RGS-RhoGEFs) that link activated heterotrimeric G protein α subunits of the G12 family to activation of the small GTPase RhoA. Unique among the RGS-RhoGEFs, PDZ-RhoGEF contains a short sequence that localizes the protein to the actin cytoskeleton. In this report, we demonstrate that the actin-binding domain, located between amino acids 561–585, directly binds to F-actin in vitro. Extensive mutagenesis identifies isoleucine 568, isoleucine 569, phenylalanine 572, and glutamic acid 573 as necessary for binding to actin and for co-localization with the actin cytoskeleton in cells. These results define a novel actin-binding sequence in PDZ-RhoGEF with a critical amino acid motif of IIxxFE. Moreover, sequence analysis identifies a similar actin-binding motif in the N-terminus of the RhoGEF frabin, and, as with PDZ-RhoGEF, mutagenesis and actin interaction experiments demonstrate a motif of LIxxFE, consisting of the key amino acids leucine 23, isoleucine 24, phenylalanine 27, and glutamic acid 28. Taken together, results with PDZ-RhoGEF and frabin identify a novel actin binding sequence. Lastly, inducible dimerization of the actin-binding region of PDZ-RhoGEF revealed a dimerization-dependent actin bundling activity in vitro. PDZ-RhoGEF exists in cells as a dimer, raising the possibility that PDZ-RhoGEF could influence actin structure independent of its ability to activate RhoA. PMID:19618964

RhoA/ROCK may involve in cardiac hypertrophy induced by experimental hyperthyroidism.

PubMed

Na, Wang; Peng, Guan; Jianping, Zhang; Yanzhong, Chang; Shengjiang, Guan; Li, Chu

2012-10-01

In this study, the role of the RhoA/Rho-kinase (RhoA/ROCK)-signaling pathway in cardiovascular dysfunction associated with hyperthyroidism was examined with the use of fasudil, a Rho-kinase inhibitor. Male Spraque-Dawley rats were treated with l-thyroxine (T(4)) alone, T(4) + low-dose fasudil (2 mg/kg/day) or T(4) + high-dose fasudil (10 mg/kg/day) and compared with control animals. Rats in the T(4) group showed an increase in the ratio of heart weight to body weight, which was ameliorated by fasudil at both low and high doses. Morphometric and hemodynamic parameters were also evaluated and confirmed that fasudil attenuated the cardiac hypertrophy induced by T(4). The extent of phosphorylation of the myosin phosphatase targeting subunit was quantified by Western blotting to evaluate the activity of Rho-kinase in the heart tissue. Both Western blotting and reverse transcriptase-polymerase chain reaction analyses revealed enhancement of Rho-kinase and activator protein 1 activity and reduction of c-FLIP(L) expression in the T(4) group, and this response was inhibited by fasudil in a dose-dependent manner. Furthermore, fasudil inhibited apoptosis induced by T(4) as evidenced by the detection of terminal deoxynucleotidyl transferase dUTP nick end labeling-positive cells and the expressions of bax and bcl-2. These results suggested that the RhoA/ROCK pathway is involved in the cardiac hypertrophy induced by experimental hyperthyroidism. The antagonism of this pathway may thus be useful as an alternative target in the treatment of hyperthyroid heart disease.

The Andes Virus Nucleocapsid Protein Directs Basal Endothelial Cell Permeability by Activating RhoA

PubMed Central

Gorbunova, Elena E.; Simons, Matthew J.; Gavrilovskaya, Irina N.

2016-01-01

ABSTRACT Andes virus (ANDV) predominantly infects microvascular endothelial cells (MECs) and nonlytically causes an acute pulmonary edema termed hantavirus pulmonary syndrome (HPS). In HPS patients, virtually every pulmonary MEC is infected, MECs are enlarged, and infection results in vascular leakage and highly lethal pulmonary edema. We observed that MECs infected with the ANDV hantavirus or expressing the ANDV nucleocapsid (N) protein showed increased size and permeability by activating the Rheb and RhoA GTPases. Expression of ANDV N in MECs increased cell size by preventing tuberous sclerosis complex (TSC) repression of Rheb-mTOR-pS6K. N selectively bound the TSC2 N terminus (1 to 1403) within a complex containing TSC2/TSC1/TBC1D7, and endogenous TSC2 reciprocally coprecipitated N protein from ANDV-infected MECs. TSCs normally restrict RhoA-induced MEC permeability, and we found that ANDV infection or N protein expression constitutively activated RhoA. This suggests that the ANDV N protein alone is sufficient to activate signaling pathways that control MEC size and permeability. Further, RhoA small interfering RNA, dominant-negative RhoA(N19), and the RhoA/Rho kinase inhibitors fasudil and Y27632 dramatically reduced the permeability of ANDV-infected MECs by 80 to 90%. Fasudil also reduced the bradykinin-directed permeability of ANDV and Hantaan virus-infected MECs to control levels. These findings demonstrate that ANDV activation of RhoA causes MEC permeability and reveal a potential edemagenic mechanism for ANDV to constitutively inhibit the basal barrier integrity of infected MECs. The central importance of RhoA activation in MEC permeability further suggests therapeutically targeting RhoA, TSCs, and Rac1 as potential means of resolving capillary leakage during hantavirus infections. PMID:27795403

Involvement of RhoGDI2 in the resistance of colon cancer cells to 5-fluorouracil.

PubMed

Zheng, Zhong; Li, Jianfang; He, Xiangyi; Chen, Xuehua; Yu, Beiqin; Ji, Jun; Zhang, Jianian; Wang, Tingfeng; Gu, Qinlong; Zhu, Zhenggang; Liu, Bingya

2010-01-01

The acquisition of resistance to 5-FU is one of the most prominent obstacles to successful chemotherapy, and the mechanisms underlying the resistance are not fully understood. The aim of this study is to identify novel mediators of 5-FU resistance in colon cancer cells. LoVo colon cancer cells were induced to 5-FU resistance in vitro. The global protein profiles between LoVo and its 5-FU resistant derivative cell line LoVo/5-FU were analyzed by two dimensional gel electrophoresis-based comparative proteomics. The identified proteins expression was confirmed by Western blot analysis. The cytotoxicity of 5-FU was measured in LoVo/5-FU after knockdown of RhoGDI2 (one of the identified protien). Three differentially expressed proteins were identified. RhoGDI2 and CapG were upregulated, whereas proapoptotic protein Maspin was down-regulated in LoVo/5-FU and validated by Western blotting. Furthermore, knockdown of RhoGDI2 expression by transfection with the RhoGDI2-specific siRNA significantly reduced the resistance to 5-FU in LoVo/5-FU (p < 0.05). These novel data suggest that these differentially expressed proteins may contribute to the development of 5-FU resistance in colon cancer cells.

Measurement of direct f0(980) photoproduction on the proton.

PubMed

Battaglieri, M; De Vita, R; Szczepaniak, A P; Adhikari, K P; Aghasyan, M; Amaryan, M J; Ambrozewicz, P; Anghinolfi, M; Asryan, G; Avakian, H; Bagdasaryan, H; Baillie, N; Ball, J P; Baltzell, N A; Batourine, V; Bedlinskiy, I; Bellis, M; Benmouna, N; Berman, B L; Bibrzycki, L; Biselli, A S; Bookwalter, C; Bouchigny, S; Boiarinov, S; Bradford, R; Branford, D; Briscoe, W J; Brooks, W K; Bültmann, S; Burkert, V D; Calarco, J R; Careccia, S L; Carman, D S; Casey, L; Chen, S; Cheng, L; Clinton, E; Cole, P L; Collins, P; Crabb, D; Crannell, H; Crede, V; Cummings, J P; Dale, D; Daniel, A; Dashyan, N; De Masi, R; De Sanctis, E; Degtyarenko, P V; Deur, A; Dhamija, S; Dharmawardane, K V; Dickson, R; Djalali, C; Dodge, G E; Donnelly, J; Doughty, D; Dugger, M; Dzyubak, O P; Egiyan, H; Egiyan, K S; El Fassi, L; Elouadrhiri, L; Eugenio, P; Fedotov, G; Fersch, R; Forest, T A; Fradi, A; Gabrielyan, M Y; Gan, L; Garçon, M; Gasparian, A; Gavalian, G; Gevorgyan, N; Gilfoyle, G P; Giovanetti, K L; Girod, F X; Glamazdin, O; Goett, J; Goetz, J T; Gohn, W; Golovatch, E; Gordon, C I O; Gothe, R W; Graham, L; Griffioen, K A; Guidal, M; Guler, N; Guo, L; Gyurjyan, V; Hadjidakis, C; Hafidi, K; Hakobyan, H; Hakobyan, R S; Hanretty, C; Hardie, J; Hassall, N; Heddle, D; Hersman, F W; Hicks, K; Hleiqawi, I; Holtrop, M; Hyde, C E; Ilieva, Y; Ireland, D G; Ishkhanov, B S; Isupov, E L; Ito, M M; Jenkins, D; Jo, H S; Johnstone, J R; Joo, K; Juengst, H G; Kageya, T; Kalantarians, N; Keller, D; Kellie, J D; Khandaker, M; Khetarpal, P; Kim, W; Klein, A; Klein, F J; Klimenko, A V; Konczykowski, P; Kossov, M; Krahn, Z; Kramer, L H; Kubarovsky, V; Kuhn, J; Kuhn, S E; Kuleshov, S V; Kuznetsov, V; Lachniet, J; Laget, J M; Langheinrich, J; Lawrence, D; Lee, T; Lesniak, L; Li, Ji; Livingston, K; Lowry, M; Lu, H Y; Maccormick, M; Malace, S; Markov, N; Mattione, P; McCracken, M E; McKinnon, B; Mecking, B A; Melone, J J; Mestayer, M D; Meyer, C A; Mibe, T; Mikhailov, K; Mineeva, T; Minehart, R; Mirazita, M; Miskimen, R; Mochalov, V; Mokeev, V; Moreno, B; Moriya, K; Morrow, S A; Moteabbed, M; Munevar, E; Mutchler, G S; Nadel-Turonski, P; Nakagawa, I; Nasseripour, R; Niccolai, S; Niculescu, G; Niculescu, I; Niczyporuk, B B; Niroula, M R; Niyazov, R A; Nozar, M; Osipenko, M; Ostrovidov, A I; Park, K; Park, S; Pasyuk, E; Paris, M; Paterson, C; Pereira, S Anefalos; Pierce, J; Pivnyuk, N; Pocanic, D; Pogorelko, O; Pozdniakov, S; Price, J W; Prok, Y; Protopopescu, D; Raue, B A; Riccardi, G; Ricco, G; Ripani, M; Ritchie, B G; Rosner, G; Rossi, P; Sabatié, F; Saini, M S; Salamanca, J; Salgado, C; Sandorfi, A; Santoro, J P; Sapunenko, V; Schott, D; Schumacher, R A; Serov, V S; Sharabian, Y G; Sharov, D; Shvedunov, N V; Smith, E S; Smith, L C; Sober, D I; Sokhan, D; Starostin, A; Stavinsky, A; Stepanyan, S; Stepanyan, S S; Stokes, B E; Stoler, P; Stopani, K A; Strakovsky, I I; Strauch, S; Taiuti, M; Tedeschi, D J; Teymurazyan, A; Tkabladze, A; Tkachenko, S; Todor, L; Tur, C; Ungaro, M; Vineyard, M F; Vlassov, A V; Watts, D P; Wei, X; Weinstein, L B; Weygand, D P; Williams, M; Wolin, E; Wood, M H; Yegneswaran, A; Yurov, M; Zana, L; Zhang, J; Zhao, B; Zhao, Z W

2009-03-13

We report on the results of the first measurement of exclusive f_{0}(980) meson photoproduction on protons for E_{gamma}=3.0-3.8 GeV and -t=0.4-1.0 GeV2. Data were collected with the CLAS detector at the Thomas Jefferson National Accelerator Facility. The resonance was detected via its decay in the pi;{+}pi;{-} channel by performing a partial wave analysis of the reaction gammap-->ppi;{+}pi;{-}. Clear evidence of the f_{0}(980) meson was found in the interference between P and S waves at M_{pi;{+}pi;{-}} approximately 1 GeV. The S-wave differential cross section integrated in the mass range of the f_{0}(980) was found to be a factor of about 50 smaller than the cross section for the rho meson. This is the first time the f_{0}(980) meson has been measured in a photoproduction experiment.

A multipronged strategy of an anti-terminator protein to overcome Rho-dependent transcription termination

PubMed Central

Muteeb, Ghazala; Dey, Debashish; Mishra, Saurabh; Sen, Ranjan

2012-01-01

One of the important role of Rho-dependent transcription termination in bacteria is to prevent gene expressions from the bacteriophage DNA. The transcription anti-termination systems of the lambdoid phages have been designed to overcome this Rho action. The anti-terminator protein N has three interacting regions, which interact with the mRNA, with the NusA and with the RNA polymerase. Here, we show that N uses all these interaction modules to overcome the Rho action. N and Rho co-occupy their overlapping binding sites on the nascent RNA (the nutR/tR1 site), and this configuration slows down the rate of ATP hydrolysis and the rate of RNA release by Rho from the elongation complex. N-RNA polymerase interaction is not too important for this Rho inactivation process near/at the nutR site. This interaction becomes essential when the elongation complex moves away from the nutR site. From the unusual NusA-dependence property of a Rho mutant E134K, a suppressor of N, we deduced that the N-NusA complex in the anti-termination machinery reduces the efficiency of Rho by removing NusA from the termination pathway. We propose that NusA-remodelling is also one of the mechanisms used by N to overcome the termination signals. PMID:23024214

A multipronged strategy of an anti-terminator protein to overcome Rho-dependent transcription termination.

PubMed

Muteeb, Ghazala; Dey, Debashish; Mishra, Saurabh; Sen, Ranjan

2012-12-01

One of the important role of Rho-dependent transcription termination in bacteria is to prevent gene expressions from the bacteriophage DNA. The transcription anti-termination systems of the lambdoid phages have been designed to overcome this Rho action. The anti-terminator protein N has three interacting regions, which interact with the mRNA, with the NusA and with the RNA polymerase. Here, we show that N uses all these interaction modules to overcome the Rho action. N and Rho co-occupy their overlapping binding sites on the nascent RNA (the nutR/tR1 site), and this configuration slows down the rate of ATP hydrolysis and the rate of RNA release by Rho from the elongation complex. N-RNA polymerase interaction is not too important for this Rho inactivation process near/at the nutR site. This interaction becomes essential when the elongation complex moves away from the nutR site. From the unusual NusA-dependence property of a Rho mutant E134K, a suppressor of N, we deduced that the N-NusA complex in the anti-termination machinery reduces the efficiency of Rho by removing NusA from the termination pathway. We propose that NusA-remodelling is also one of the mechanisms used by N to overcome the termination signals.

Structural Basis of Membrane Targeting by the Dock180 Family of Rho Family Guanine Exchange Factors (Rho-GEFs)*

PubMed Central

Premkumar, Lakshmanane; Bobkov, Andrey A.; Patel, Manishha; Jaroszewski, Lukasz; Bankston, Laurie A.; Stec, Boguslaw; Vuori, Kristiina; Côté, Jean-Francois; Liddington, Robert C.

2010-01-01

The Dock180 family of atypical Rho family guanine nucleotide exchange factors (Rho-GEFs) regulate a variety of processes involving cellular or subcellular polarization, including cell migration and phagocytosis. Each contains a Dock homology region-1 (DHR-1) domain that is required to localize its GEF activity to a specific membrane compartment where levels of phosphatidylinositol (3,4,5)-trisphosphate (PtdIns(3,4,5)P3) are up-regulated by the local activity of PtdIns 3-kinase. Here we define the structural and energetic bases of phosphoinositide specificity by the DHR-1 domain of Dock1 (a GEF for Rac1), and show that DHR-1 utilizes a C2 domain scaffold and surface loops to create a basic pocket on its upper surface for recognition of the PtdIns(3,4,5)P3 head group. The pocket has many of the characteristics of those observed in pleckstrin homology domains. We show that point mutations in the pocket that abolish phospholipid binding in vitro ablate the ability of Dock1 to induce cell polarization, and propose a model that brings together recent mechanistic and structural studies to rationalize the central role of DHR-1 in dynamic membrane targeting of the Rho-GEF activity of Dock180. PMID:20167601

Inhibition of the RhoA GTPase Activity Increases Sensitivity of Melanoma Cells to UV Radiation Effects

PubMed Central

Espinha, Gisele; Osaki, Juliana Harumi; Costa, Erico Tosoni; Forti, Fabio Luis

2016-01-01

Ultraviolet radiation is the main cause of DNA damage to melanocytes and development of melanoma, one of the most lethal human cancers, which leads to metastasis due to uncontrolled cell proliferation and migration. These phenotypes are mediated by RhoA, a GTPase overexpressed or overactivated in highly aggressive metastatic tumors that plays regulatory roles in cell cycle progression and cytoskeleton remodeling. This work explores whether the effects of UV on DNA damage, motility, proliferation, and survival of human metastatic melanoma cells are mediated by the RhoA pathway. Mutant cells expressing dominant-negative (MeWo-RhoA-N19) or constitutively active RhoA (MeWo-RhoA-V14) were generated and subjected to UV radiation. A slight reduction in migration and invasion was observed in MeWo and MeWo-RhoA-V14 cells but not in MeWo-RhoA-N19 cells, which presented inefficient motility and invasiveness associated with stress fibers fragmentation. Proliferation and survival of RhoA-deficient cells were drastically reduced by UV compared to cells displaying normal or high RhoA activity, suggesting increased sensitivity to UV. Loss of RhoA activity also caused less efficient DNA repair, with elevated levels of DNA lesions such as strand breaks and cyclobutane pyrimidine dimers (CPDs). Thus, RhoA mediates genomic stability and represents a potential target for sensitizing metastatic tumors to genotoxic agents. PMID:26823948

Subdominant Dark Matter sterile neutrino resonant production in the light of PLANCK

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

Popa, L.A.; Tonoiu, D., E-mail: lpopa@spacescience.ro, E-mail: tonoiud@spacescience.ro

2015-09-01

Few independent detections of a weak X-ray line at an energy of ∼ 3.5 keV seen toward a number of astrophysical sites have been reported. If this signal will be confirmed to be the signature of decaying DM sterile neutrino with a mass of ∼ 7.1 keV, then the cosmological observables should be consistent with its properties. In this paper we make a coupled treatment of the weak decoupling, primordial nucleosynthesis and photon decoupling epochs in the sterile neutrino resonant production scenario, including the extra radiation energy density via N{sub eff}. We compute the radiation and matter perturbations including the full resonancemore » sweep solution for ν{sub α}/ν-bar {sub α} → ν{sub s} flavor conversion in the expanding Universe.We show that the cosmological measurements are in agreement with subdominant Dark Matter sterile neutrino resonant production with following parameters (errors at 95% CL): mass m{sub ν{sub s}}=6.08 ± 3.22 keV, mixing angle sin{sup 2} 2θ < 5.61 × 10{sup −10}, lepton number per flavor L{sub 4} = 1.23 ± 0.04 (L{sub 4} ≡ 10{sup 4} L{sub ν{sub a}}) and sterile neutrino mass fraction f{sub ν{sub s}}< 0.078.Our results are in good agreement with the sterile neutrino resonant production parameters inferred in ref. [1] from the linear large scale structure constraints to produce full Dark Matter density.« less

Molecular characterization of a novel RhoGAP, RRC-1 of the nematode Caenorhabditis elegans

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

Delawary, Mina; Nakazawa, Takanobu; Tezuka, Tohru

2007-06-01

The GTPase-activating proteins for Rho family GTPases (RhoGAP) transduce diverse intracellular signals by negatively regulating Rho family GTPase-mediated pathways. In this study, we have cloned and characterized a novel RhoGAP for Rac1 and Cdc42, termed RRC-1, from Caenorhabditis elegans. RRC-1 was highly homologous to mammalian p250GAP and promoted GTP hydrolysis of Rac1 and Cdc42 in cells. The rrc-1 mRNA was expressed in all life stages. Using an RRC-1::GFP fusion protein, we found that RRC-1 was localized to the coelomocytes, excretory cell, GLR cells, and uterine-seam cell in adult worms. These data contribute toward understanding the roles of Rho family GTPasesmore » in C. elegans.« less

Production and Decay of {xi}{sub c}{sup 0} at BABAR

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

Aubert, B.; Barate, R.; Boutigny, D.

Using 116.1 fb{sup -1} of data collected by the BABAR detector, we present an analysis of {xi}{sub c}{sup 0} production in B decays and from the cc continuum, with the {xi}{sub c}{sup 0} decaying into {omega}{sup -}K{sup +} and {xi}{sup -}{pi}{sup +} final states. We measure the ratio of branching fractions B({xi}{sub c}{sup 0}{yields}{omega}{sup -}K{sup +})/B({xi}{sub c}{sup 0}{yields}{xi}{sup -}{pi}{sup +}) to be 0.294{+-}0.018{+-}0.016, where the first uncertainty is statistical and the second is systematic. The {xi}{sub c}{sup 0} momentum spectrum is measured on and 40 MeV below the {upsilon}(4S) resonance. From these spectra the branching fraction product B(B{yields}{xi}{sub c}{sup 0}X)xB({xi}{submore » c}{sup 0}{yields}{xi}{sup -}{pi}{sup +}) is measured to be (2.11{+-}0.19{+-}0.25)x10{sup -4}, and the cross-section product {sigma}(e{sup +}e{sup -}{yields}{xi}{sub c}{sup 0}X)xB({xi}{sub c}{sup 0}{yields}{xi}{sup -}{pi}{sup +}) from the continuum is measured to be (388{+-}39{+-}41) fb at a center-of-mass energy of 10.58 GeV.« less

Isolation and characterization of a 66-kDa protein from rat liver plasma membrane with RhoA-stimulated phospholipase D activity.

PubMed

Dunkirk, Shawn G; Wallert, Mark A; Baumgartner, Matt L; Provost, Joseph J

2002-02-01

A 66-kDa molecular weight protein with phospholipase D activity was solubilized and partially purified from rat liver plasma membrane. The activity and regulation of this phospholipase D have been characterized. Immunoblot analyses indicated that the enzyme was distinct from hPLD1 and PLD2, but was recognized by an antibody to the 12 terminal amino acids of PLD1. PLD activity was stimulated by 1-100 microM Ca(2+) and Mg(2+) and displayed a pH optimum of 7.5. Activity was inhibited by both saturated and unsaturated fatty acids. This PLD was activated in an ATP-independent manner by the PKC isozymes alpha and betaII but not activated by other PKC isozymes. It was also stimulated by the small G-proteins RhoA and ARF. RhoA stimulated the greatest activation, followed by ARF and PKC(alpha). This enzyme was further activated in a synergistic manner when combinations of PKC(alpha) and RhoA or ARF were used. This enzyme displayed a greater response activation by RhoA than to activation by ARF. While a potential breakdown product of PLD1, activation by RhoA indicates that the PLD characterized here is distinct from the other PLDs cloned or isolated to date. Copyright 2002 Elsevier Science (USA).

RhoA-Mediated Functions in C3H10T1/2 Osteoprogenitors Are Substrate Topography Dependent.

PubMed

Ogino, Yoichiro; Liang, Ruiwei; Mendonça, Daniela B S; Mendonça, Gustavo; Nagasawa, Masako; Koyano, Kiyoshi; Cooper, Lyndon F

2016-03-01

Surface topography broadly influences cellular responses. Adherent cell activities are regulated, in part, by RhoA, a member of the Rho-family of GTPases. In this study, we evaluated the influence of surface topography on RhoA activity and associated cellular functions. The murine mesenchymal stem cell line C3H10T1/2 cells (osteoprogenitor cells) were cultured on titanium substrates with smooth topography (S), microtopography (M), and nanotopography (N) to evaluate the effect of surface topography on RhoA-mediated functions (cell spreading, adhesion, migration, and osteogenic differentiation). The influence of RhoA activity in the context of surface topography was also elucidated using RhoA pharmacologic inhibitor. Following adhesion, M and N adherent cells developed multiple projections, while S adherent cells had flattened and widespread morphology. RhoA inhibitor induced remarkable longer and thinner cytoplasmic projections on all surfaces. Cell adhesion and osteogenic differentiation was topography dependent with S < M and N surfaces. RhoA inhibition increased adhesion on S and M surfaces, but not N surfaces. Cell migration in a wound healing assay was greater on S versus M versus N surfaces and RhoA inhibitor increased S adherent cell migration, but not N adherent cell migration. RhoA inhibitor enhanced osteogenic differentiation in S adherent cells, but not M or N adherent cells. RhoA activity was surface topography roughness dependent (S < M, N). RhoA activity and -mediated functions are influenced by surface topography. Smooth surface adherent cells appear highly sensitive to RhoA function, while nano-scale topography adherent cell may utilize alternative cellular signaling pathway(s) to influence adherent cellular functions regardless of RhoA activity. © 2015 Wiley Periodicals, Inc.

Rho-dependent kinase is involved in agonist-activated calcium entry in rat arteries

PubMed Central

Ghisdal, Philippe; Vandenberg, Greet; Morel, Nicole

2003-01-01

The present study was aimed at investigating whether, besides its pivotal role in Ca2+-independent contraction of smooth muscle, Rho-kinase is involved in the mechanisms underlying the Ca2+ signal activated by noradrenaline in arteries. In rat aorta and mesenteric artery, the Rho-kinase inhibitor Y-27632 (10 μM) completely relaxed the contraction evoked by noradrenaline (1 μM) and simultaneously inhibited the Ca2+ signal by 54 ± 1 % (mesenteric artery) and 71 ± 15 % (aorta), and the cell membrane depolarisation by 56 ± 11 % (mesenteric artery). A similar effect was observed in arteries contracted by AlF4−, while in KCl-contracted arteries, Y-27632 decreased tension without changing cytosolic Ca2+. The same effects were observed with another inhibitor of Rho-kinase (HA1077) but not with an inhibitor of protein kinase C (Ro-31–8220). Effects of Y-27632 were not prevented by incubating the artery in 25 mM KCl, with K+ channel blockers or with the Ca2+ channel blocker nimodipine. Y-27632 did not affect either the increase in the production of inositol phosphates activated by noradrenaline, or the release of Ca2+ from non-mitochondrial stores evoked by InsP3 in permeabilised aortic cells, or the Ca2+ signals evoked by thapsigargin or caffeine. The capacitative Ca2+ entry activated by thapsigargin was not impaired by Y-27632, but the entry of Ba2+ activated by noradrenaline in the presence of nimodipine was blocked by 10 μM Y-27632. These results indicate that Rho-kinase is involved in noradrenaline activation of a Ca2+ entry distinct from voltage- or store-operated channels in rat arteries. PMID:12853654

High-mobility group box 1 inhibits HCO3− absorption in the medullary thick ascending limb through RAGE-Rho-ROCK-mediated inhibition of basolateral Na+/H+ exchange

PubMed Central

Watts, Bruns A.; George, Thampi; Badalamenti, Andrew

2016-01-01

High-mobility group box 1 (HMGB1) is a nuclear protein released extracellularly in response to infection or injury, where it activates immune responses and contributes to the pathogenesis of kidney dysfunction in sepsis and sterile inflammatory disorders. Recently, we demonstrated that HMGB1 inhibits HCO3− absorption in perfused rat medullary thick ascending limbs (MTAL) through a basolateral receptor for advanced glycation end products (RAGE)-dependent pathway that is additive to Toll-like receptor 4 (TLR4)-ERK-mediated inhibition by LPS (Good DW, George T, Watts BA III. Am J Physiol Renal Physiol 309: F720–F730, 2015). Here, we examined signaling and transport mechanisms that mediate inhibition by HMGB1. Inhibition of HCO3− absorption by HMGB1 was eliminated by the Rho-associated kinase (ROCK) inhibitor Y27632 and by a specific inhibitor of Rho, the major upstream activator of ROCK. HMGB1 increased RhoA and ROCK1 activity. HMGB1-induced ROCK1 activation was eliminated by the RAGE antagonist FPS-ZM1 and by inhibition of Rho. The Rho and ROCK inhibitors had no effect on inhibition of HCO3− absorption by bath LPS. Inhibition of HCO3− absorption by HMGB1 was eliminated by bath amiloride, 0 Na+ bath, and the F-actin stabilizer jasplakinolide, three conditions that selectively prevent inhibition of MTAL HCO3− absorption mediated through NHE1. HMGB1 decreased basolateral Na+/H+ exchange activity through activation of ROCK. We conclude that HMGB1 inhibits HCO3− absorption in the MTAL through a RAGE-RhoA-ROCK1 signaling pathway coupled to inhibition of NHE1. The HMGB1-RAGE-RhoA-ROCK1 pathway thus represents a potential target to attenuate MTAL dysfunction during sepsis and other inflammatory disorders. HMGB1 and LPS inhibit HCO3− absorption through different receptor signaling and transport mechanisms, which enables these pathogenic mediators to act directly and independently to impair MTAL function. PMID:27358052

Nε-Fatty acylation of Rho GTPases by a MARTX toxin effector.

PubMed

Zhou, Yan; Huang, Chunfeng; Yin, Li; Wan, Muyang; Wang, Xiaofei; Li, Lin; Liu, Yanhua; Wang, Zhao; Fu, Panhan; Zhang, Ni; Chen, She; Liu, Xiaoyun; Shao, Feng; Zhu, Yongqun

2017-10-27

The multifunctional autoprocessing repeats-in-toxin (MARTX) toxins are a family of large toxins that are extensively distributed in bacterial pathogens. MARTX toxins are autocatalytically cleaved to multiple effector domains, which are released into host cells to modulate the host signaling pathways. The Rho guanosine triphosphatase (GTPase) inactivation domain (RID), a conserved effector domain of MARTX toxins, is implicated in cell rounding by disrupting the host actin cytoskeleton. We found that the RID is an N ε -fatty acyltransferase that covalently modifies the lysine residues in the C-terminal polybasic region of Rho GTPases. The resulting fatty acylation inhibited Rho GTPases and disrupted Rho GTPase-mediated signaling in the host. Thus, RID can mediate the lysine N ε -fatty acylation of mammalian proteins and represents a family of toxins that harbor N-fatty acyltransferase activities in bacterial pathogens. Copyright © 2017 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works.

[Effect of Different Stimulating Strength of Electroacupuncture on Gastrointestinal Motility and RhoA/ROCK Signaling in Gastric Antral Smooth Muscle in Diabetic Gastroparesis Rats].

PubMed

Wu, Xue-Fen; Chen, Xiao-Li; Zheng, Xue-Na; Guo, Xin; Xie, Zhi-Qiang; Liu, Li; Wei, Xin-Ran; Yue, Zeng-Hui

2018-03-25

To observe the effect of different strength of electroacupuncture (EA) stimulation on gastrointestinal motility and Ras homolog gene family member (RhoA)/Rho associated coiled-coil forming protein kinase (ROCK) signaling in diabetic gastroparesis (DGP) rats, so as to reveal the underlying mechanisms of EA for improving DGP. Sixty SD rats were randomly and equally divided into blank control, DGP model, weak EA, medium EA, and strong EA groups ( n ＝12 rats in each). The DGP model was established by intraperitoneal injection of streptozotocin (STZ, 55 mmol/kg, 2%) and high-sugar and high-fat fodder feeding for 8 weeks. EA (0.12, 0.24, 0.36 mA, 20 Hz/100 Hz) was applied to "Zusanli" (ST 36), "Sanyinjiao" (SP 6) and "Liangmen" (ST 21) for 20 min, once daily for 15 successive days. Blood glucose levels were measured weekly with blood glucose meter and blood glucose test paper. Fecal phenol red excretion method was used to display gastric emptying and small intestinal propulsion function. The expression of RhoA protein in the gastric antral smooth muscle tissue was detected by immunohistochemistry and Western blot (WB), separately, and that of ROCK, myosin phosphatase target subunit 1 (MYPT 1) and phosphorylated (p)-MYPT 1 proteins in gastric antrum detected by WB. Compared with the blank control group, the gastric emptying rate and small intestine propulsion rate of the model group were significantly decreased ( P <0.05), and the blood glucose level was remarkably increased ( P <0.05). Moreover, the expression levels of RhoA, ROCK, MYPT 1 and p-MYPT 1 proteins in the gastric antrum were significantly down-regulated relevant to the control group ( P <0.05). After administration of EA, the decreased gastric emptying rate and intestinal propulsion rate, and the down-regulated expression of RhoA, ROCK, MYPT 1 and p-MYPT 1 proteins were significantly increased in the strong, medium and weak EA stimulation groups ( P <0.05). Comparison among the 3 EA groups showed that the

Knockdown of RhoA expression alters ovarian cancer biological behavior in vitro and in nude mice.

PubMed

Wang, Xiaoxia; Jiang, Wenyan; Kang, Jiali; Liu, Qicai; Nie, Miaoling

2015-08-01

RhoA regulates cell proliferation, migration, angiogenesis and gene expression. Altered RhoA activity contributes to cancer progression. The present study investigated the effects of RhoA knockdown on the regulation of ovarian cancer biological behavior in vitro and in nude mice. The expression of RhoA was knocked down using a lentivirus carrying RhoA short hairpin RNA (shRNA) in ovarian cancer cells and was confirmed by reverse transcription-quantitative polymerase chain reaction (RT-qPCR) and western blot analysis. The altered ovarian cancer biological behaviors were assayed by cell viability, terminal deoxynucleotidyltransferase-mediated dUTP nick end-labeling (TUNEL), migration, invasion, and nude mice tumorigenicity assays, while the altered gene expression was detected by RT-qPCR and western blot analysis. The results showed that lentivirus-carrying RhoA shRNA significantly suppressed RhoA expression in ovarian cancer cells, which suppressed tumor cell viability, migration, invasion and adhesion in vitro. RhoA silencing also inhibited the tumorigenicity of ovarian cancer cells in nude mice, which was characterized by the suppression of tumor xenograft formation and growth and induction of tumor cell apoptosis. The results of the present study demonstrated that knockdown of RhoA expression had a significant antitumor effect on ovarian cancer cells in vitro and in nude mice, suggesting that RhoA may be a target for the development of a novel therapeutic strategy in the control of ovarian cancer.

Regulation of hepatic Na+/K+-ATPase in obese female and male rats: involvement of ERK1/2, AMPK, and Rho/ROCK.

PubMed

Stanimirovic, Julijana; Obradovic, Milan; Panic, Anastasija; Petrovic, Voin; Alavantic, Dragan; Melih, Irena; Isenovic, Esma R

2018-03-01

In this study, we assessed whether the disturbed regulation of sodium/potassium-adenosine-triphosphatase (Na + /K + -ATPase) occurs as a consequence of obesity-induced IR in sex-specific manner. We also assessed whether alterations of IRS/PI3K/Akt, ERK1/2, AMPKα, and RhoA/ROCK signaling cascades have an important role in this pathology. Female and male Wistar rats (150-200 g, 8 weeks old) were fed a standard laboratory diet or a high-fat (HF) diet (42% fat) for 10 weeks. The activity of hepatic Na + /K + -ATPase and Rho, and the association of IRS-1/p85 were assessed in liver. Furthermore, the protein level of α 1 Na + /K + -ATPase in plasma membrane fractions, and protein levels of IRS-1, PI3K-p85, -p110, RhoA, ROCK1, ROCK2, ERK1/2, AMPKα, ERα, and ERβ in liver lysates were assessed. The expression of hepatic α 1 Na + /K + -ATPase mRNA was also analyzed by qRT-PCR. The results show that HF-fed female rats exhibited an increase in hepatic ERK1/2 (p < 0.05) and AMPKα (p < 0.05) phosphorylation levels, unchanged level of Na + /K + -ATPase α 1 mRNA, decreased level of Na + /K + -ATPase activity (p < 0.05), and decreased α 1 Na + /K + -ATPase protein expression (p < 0.01). In liver of HF-fed male rats, results show decreased levels of Na + /K + -ATPase activity (p < 0.01), both protein and mRNA of α 1 subunit (p < 0.05), but significant increase in Rho activity (p < 0.05). Our results indicate significant sex differences in α 1 Na + /K + -ATPase mRNA expression and activation of ERK1/2, AMPKα, and Rho in the liver. Exploring the sex-specific factors and pathways that promote obesity-related diseases may lead to a better understanding of pathogenesis and discovering new therapeutic targets.

The RhoA-ROCK-PTEN pathway as a molecular switch for anchorage dependent cell behavior.

PubMed

Yang, Seungwon; Kim, Hyun-Man

2012-04-01

The proliferation of anchorage-dependent cells of mesenchymal origin requires the attachment of the cells to substrates. Thus, cells that are poorly attached to substrates exhibit retarded cell cycle progression or apoptotic death. A major disadvantage of most polymers used in tissue engineering is their hydrophobicity; hydrophobic surfaces do not allow cells to attach firmly and, therefore, do not allow normal proliferation rates. In this study, we investigated the molecular mechanism underlying the reduced proliferation rate of cells that are poorly attached to substrates. There was an inverse relationship between the activity of the small GTPase RhoA (RhoA) and the cell proliferation rate. RhoA activity correlated inversely with the strength of cell adhesion to the substrates. The high RhoA activity in the cells poorly attached to substrates caused an increase in the activity of Rho-associated kinase (ROCK), a well-known effector of RhoA that upregulated the activity of phosphatase and tensin homolog (PTEN). The resulting activated PTEN downregulated Akt activity, which is essential for cell proliferation. Thus, the cells that were poorly attached to substrates showed low levels of cell proliferation because the RhoA-ROCK-PTEN pathway was hyperactive. In addition, RhoA activity seemed to be related to focal adhesion kinase (FAK) activity. Weak FAK activity in these poorly attached cells failed to downregulate the high RhoA activity that restrained cell proliferation. Interestingly, reducing the expression of any component of the RhoA-ROCK-PTEN pathway rescued the proliferation rate without physico-chemical surface modifications. Based on these results, we suggest that the RhoA-ROCK-PTEN pathway acts as a molecular switch to control cell proliferation and determine anchorage dependence. In cells that are poorly attached to substrates, its inhibition is sufficient to restore cell proliferation without the need for physico-chemical modification of the material

Fine regulation of RhoA and Rock is required for skeletal muscle differentiation.

PubMed

Castellani, Loriana; Salvati, Erica; Alemà, Stefano; Falcone, Germana

2006-06-02

The RhoA GTPase controls a variety of cell functions such as cell motility, cell growth, and gene expression. Previous studies suggested that RhoA mediates signaling inputs that promote skeletal myogenic differentiation. We show here that levels and activity of RhoA protein are down-regulated in both primary avian myoblasts and mouse satellite cells undergoing differentiation, suggesting that a fine regulation of this GTPase is required. In addition, ectopic expression of activated RhoA in primary quail myocytes, but not in mouse myocytes, inhibits accumulation of muscle-specific proteins and cell fusion. By disrupting RhoA signaling with specific inhibitors, we have shown that this GTPase, although required for cell identity in proliferating myoblasts, is not essential for commitment to terminal differentiation and muscle gene expression. Ectopic expression of an activated form of its downstream effector, Rock, impairs differentiation of both avian and mouse myoblasts. Conversely, Rock inhibition with specific inhibitors and small interfering RNA-mediated gene silencing leads to accelerated progression in the lineage and enhanced cell fusion, underscoring a negative regulatory function of Rock in myogenesis. Finally, we have reported that Rock acts independently from RhoA in preventing myoblast exit from the cell cycle and commitment to differentiation and may receive signaling inputs from Raf-1 kinase.

Synthetic 8-hydroxydeoxyguanosine inhibited metastasis of pancreatic cancer through concerted inhibitions of ERM and Rho-GTPase.

PubMed

Park, Jong-Min; Han, Young-Min; Jeong, Migyeong; Chung, Myung Hee; Kwon, Chang Il; Ko, Kwang Hyun; Hahm, Ki Baik

2017-09-01

8-hydroxydeoxyguanosine (8-OHdG) is generated consequent to oxidative stress, but its paradoxical anti-oxidative, anti-inflammatory, and anti-mutagenic effects via Rho-GTPase inhibition were noted in various models of inflammation and cancer. Metastasis occurs through cell detachment, epithelial-mesenchymal transition (EMT), and cell migration; during these processes, changes in cell morphology are initiated through Rho-GTPase-dependent actin cytoskeleton polymerization. In this study, we explored the anti-metastatic mechanisms of 8-OHdG in Panc-1 pancreatic cancer cells. 8-OHdG inhibits cell migration by inactivating ERM and Rho-GTPase proteins, and inhibiting focal adhesion kinase (FAK) and matrix metalloproteinases (MMPs). At 15min, 8-OHdG significantly inactivated ERM (p < 0.05) and led to a significant retardation of wound healing; siERM and H1152 (ROCK inhibitor) had similar effects (p < 0.05). However, FAK inhibitor 14, DPI (NOX inhibitor), and NAC (antioxidant) significantly delayed wound healing without inhibiting ERM or CD44 (p < 0.05). In the experiments on cell migration, siERM, siCD44, DPI, and 8-OHdG significantly inhibited MMPs. 8-OHdG significantly decreased DCF-DA activation in Panc-1 pancreatic cancer cells and down-regulated NOXs (nox-1, nox-2, and nox-3). Finally, all of these anti-migration actions of 8-OHdG resulted in significant inhibition of EMT, as evidenced by the up-regulation of ZO-1 and claudin-1 and down-regulation of vimentin. We found significant inhibition of lung metastasis of Panc-1 cells by 8-OHdG. In conclusion, exogenous 8-OHdG had potent anti-metastasis effects mediated by either ERM or Rho GTPase inhibition in metastasis-prone pancreatic cancer cells. Copyright © 2017 Elsevier Inc. All rights reserved.

Deregulation of HEF1 Impairs M-Phase Progression by Disrupting the RhoA Activation Cycle

PubMed Central

Dadke, Disha; Jarnik, Michael; Pugacheva, Elena N.; Singh, Mahendra K.; Golemis, Erica A.

2006-01-01

The focal adhesion-associated signaling protein HEF1 undergoes a striking relocalization to the spindle at mitosis, but a function for HEF1 in mitotic signaling has not been demonstrated. We here report that overexpression of HEF1 leads to failure of cells to progress through cytokinesis, whereas depletion of HEF1 by small interfering RNA (siRNA) leads to defects earlier in M phase before cleavage furrow formation. These defects can be explained mechanistically by our determination that HEF1 regulates the activation cycle of RhoA. Inactivation of RhoA has long been known to be required for cytokinesis, whereas it has recently been determined that activation of RhoA at the entry to M phase is required for cellular rounding. We find that increased HEF1 sustains RhoA activation, whereas depleted HEF1 by siRNA reduces RhoA activation. Furthermore, we demonstrate that chemical inhibition of RhoA is sufficient to reverse HEF1-dependent cellular arrest at cytokinesis. Finally, we demonstrate that HEF1 associates with the RhoA-GTP exchange factor ECT2, an orthologue of the Drosophila cytokinetic regulator Pebble, providing a direct means for HEF1 control of RhoA. We conclude that HEF1 is a novel component of the cell division control machinery and that HEF1 activity impacts division as well as cell attachment signaling events. PMID:16394104

42 CFR 493.859 - Standard; ABO group and D (Rho) typing.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 42 Public Health 5 2010-10-01 2010-10-01 false Standard; ABO group and D (Rho) typing. 493.859 Section 493.859 Public Health CENTERS FOR MEDICARE & MEDICAID SERVICES, DEPARTMENT OF HEALTH AND HUMAN..., Or Any Combination of These Tests § 493.859 Standard; ABO group and D (Rho) typing. (a) Failure to...

Search for resonant top-antitop production in the lepton plus jets decay mode using the full CDF data set.

PubMed

Aaltonen, T; Amerio, S; Amidei, D; Anastassov, A; Annovi, A; Antos, J; Apollinari, G; Appel, J A; Arisawa, T; Artikov, A; Asaadi, J; Ashmanskas, W; Auerbach, B; Aurisano, A; Azfar, F; Badgett, W; Bae, T; Barbaro-Galtieri, A; Barnes, V E; Barnett, B A; Barria, P; Bartos, P; Bauce, M; Bedeschi, F; Behari, S; Bellettini, G; Bellinger, J; Benjamin, D; Beretvas, A; Bhatti, A; Bland, K R; Blumenfeld, B; Bocci, A; Bodek, A; Bortoletto, D; Boudreau, J; Boveia, A; Brigliadori, L; Bromberg, C; Brucken, E; Budagov, J; Budd, H S; Burkett, K; Busetto, G; Bussey, P; Butti, P; Buzatu, A; Calamba, A; Camarda, S; Campanelli, M; Canelli, F; Carls, B; Carlsmith, D; Carosi, R; Carrillo, S; Casal, B; Casarsa, M; Castro, A; Catastini, P; Cauz, D; Cavaliere, V; Cavalli-Sforza, M; Cerri, A; Cerrito, L; Chen, Y C; Chertok, M; Chiarelli, G; Chlachidze, G; Cho, K; Chokheli, D; Ciocci, M A; Clark, A; Clarke, C; Convery, M E; Conway, J; Corbo, M; Cordelli, M; Cox, C A; Cox, D J; Cremonesi, M; Cruz, D; Cuevas, J; Culbertson, R; d'Ascenzo, N; Datta, M; De Barbaro, P; Demortier, L; Deninno, M; Devoto, F; d'Errico, M; Di Canto, A; Di Ruzza, B; Dittmann, J R; D'Onofrio, M; Donati, S; Dorigo, M; Driutti, A; Ebina, K; Edgar, R; Elagin, A; Erbacher, R; Errede, S; Esham, B; Eusebi, R; Farrington, S; Fernández Ramos, J P; Field, R; Flanagan, G; Forrest, R; Franklin, M; Freeman, J C; Frisch, H; Funakoshi, Y; Garfinkel, A F; Garosi, P; Gerberich, H; Gerchtein, E; Giagu, S; Giakoumopoulou, V; Gibson, K; Ginsburg, C M; Giokaris, N; Giromini, P; Giurgiu, G; Glagolev, V; Glenzinski, D; Gold, M; Goldin, D; Golossanov, A; Gomez, G; Gomez-Ceballos, G; Goncharov, M; González López, O; Gorelov, I; Goshaw, A T; Goulianos, K; Gramellini, E; Grinstein, S; Grosso-Pilcher, C; Group, R C; Guimaraes da Costa, J; Hahn, S R; Han, J Y; Happacher, F; Hara, K; Hare, M; Harr, R F; Harrington-Taber, T; Hatakeyama, K; Hays, C; Heinrich, J; Herndon, M; Hocker, A; Hong, Z; Hopkins, W; Hou, S; Hughes, R E; Husemann, U; Hussein, M; Huston, J; Introzzi, G; Iori, M; Ivanov, A; James, E; Jang, D; Jayatilaka, B; Jeon, E J; Jindariani, S; Jones, M; Joo, K K; Jun, S Y; Junk, T R; Kambeitz, M; Kamon, T; Karchin, P E; Kasmi, A; Kato, Y; Ketchum, W; Keung, J; Kilminster, B; Kim, D H; Kim, H S; Kim, J E; Kim, M J; Kim, S B; Kim, S H; Kim, Y K; Kim, Y J; Kimura, N; Kirby, M; Knoepfel, K; Kondo, K; Kong, D J; Konigsberg, J; Kotwal, A V; Kreps, M; Kroll, J; Kruse, M; Kuhr, T; Kurata, M; Laasanen, A T; Lammel, S; Lancaster, M; Lannon, K; Latino, G; Lee, H S; Lee, J S; Leo, S; Leone, S; Lewis, J D; Limosani, A; Lipeles, E; Liu, H; Liu, Q; Liu, T; Lockwitz, S; Loginov, A; Lucchesi, D; Lueck, J; Lujan, P; Lukens, P; Lungu, G; Lys, J; Lysak, R; Madrak, R; Maestro, P; Malik, S; Manca, G; Manousakis-Katsikakis, A; Margaroli, F; Marino, P; Martínez, M; Matera, K; Mattson, M E; Mazzacane, A; Mazzanti, P; McNulty, R; Mehta, A; Mehtala, P; Mesropian, C; Miao, T; Mietlicki, D; Mitra, A; Miyake, H; Moed, S; Moggi, N; Moon, C S; Moore, R; Morello, M J; Mukherjee, A; Muller, Th; Murat, P; Mussini, M; Nachtman, J; Nagai, Y; Naganoma, J; Nakano, I; Napier, A; Nett, J; Neu, C; Nigmanov, T; Nodulman, L; Noh, S Y; Norniella, O; Oakes, L; Oh, S H; Oh, Y D; Oksuzian, I; Okusawa, T; Orava, R; Ortolan, L; Pagliarone, C; Palencia, E; Palni, P; Papadimitriou, V; Parker, W; Pauletta, G; Paulini, M; Paus, C; Phillips, T J; Piacentino, G; Pianori, E; Pilot, J; Pitts, K; Plager, C; Pondrom, L; Poprocki, S; Potamianos, K; Prokoshin, F; Pranko, A; Ptohos, F; Punzi, G; Ranjan, N; Redondo Fernández, I; Renton, P; Rescigno, M; Riddick, T; Rimondi, F; Ristori, L; Robson, A; Rodriguez, T; Rolli, S; Ronzani, M; Roser, R; Rosner, J L; Ruffini, F; Ruiz, A; Russ, J; Rusu, V; Safonov, A; Sakumoto, W K; Sakurai, Y; Santi, L; Sato, K; Saveliev, V; Savoy-Navarro, A; Schlabach, P; Schmidt, E E; Schwarz, T; Scodellaro, L; Scuri, F; Seidel, S; Seiya, Y; Semenov, A; Sforza, F; Shalhout, S Z; Shears, T; Shepard, P F; Shimojima, M; Shochet, M; Shreyber-Tecker, I; Simonenko, A; Sinervo, P; Sliwa, K; Smith, J R; Snider, F D; Sorin, V; Song, H; Stancari, M; St Denis, R; Stelzer, B; Stelzer-Chilton, O; Stentz, D; Strologas, J; Sudo, Y; Sukhanov, A; Suslov, I; Takemasa, K; Takeuchi, Y; Tang, J; Tecchio, M; Teng, P K; Thom, J; Thomson, E; Thukral, V; Toback, D; Tokar, S; Tollefson, K; Tomura, T; Tonelli, D; Torre, S; Torretta, D; Totaro, P; Trovato, M; Ukegawa, F; Uozumi, S; Vázquez, F; Velev, G; Vellidis, C; Vernieri, C; Vidal, M; Vilar, R; Vizán, J; Vogel, M; Volpi, G; Wagner, P; Wallny, R; Wang, S M; Warburton, A; Waters, D; Wester, W C; Whiteson, D; Wicklund, A B; Wilbur, S; Williams, H H; Wilson, J S; Wilson, P; Winer, B L; Wittich, P; Wolbers, S; Wolfe, H; Wright, T; Wu, X; Wu, Z; Yamamoto, K; Yamato, D; Yang, T; Yang, U K; Yang, Y C; Yao, W-M; Yeh, G P; Yi, K; Yoh, J; Yorita, K; Yoshida, T; Yu, G B; Yu, I; Zanetti, A M; Zeng, Y; Zhou, C; Zucchelli, S

2013-03-22

This Letter reports a search for a narrow resonant state decaying into two W bosons and two b quarks where one W boson decays leptonically and the other decays into a quark-antiquark pair. The search is particularly sensitive to top-antitop resonant production. We use the full data sample of proton-antiproton collisions at a center-of-mass energy of 1.96 TeV collected by the CDF II detector at the Fermilab Tevatron, corresponding to an integrated luminosity of 9.45 fb(-1). No evidence for resonant production is found, and upper limits on the production cross section times branching ratio for a narrow resonant state are extracted. Within a specific benchmark model, we exclude a Z' boson with mass, M(Z'), below 915 GeV/c(2) decaying into a top-antitop pair at the 95% credibility level assuming a Z' boson decay width of Γ(Z') = 0.012 M(Z'). This is the most sensitive search for a narrow qq-initiated tt resonance in the mass region below 750 GeV/c(2).

Astrophysical neutrino production diagnostics with the Glashow resonance

NASA Astrophysics Data System (ADS)

Biehl, Daniel; Fedynitch, Anatoli; Palladino, Andrea; Weiler, Tom J.; Winter, Walter

2017-01-01

We study the Glashow resonance bar nue + e- → W- → hadrons at 6.3 PeV as diagnostic of the production processes of ultra-high energy neutrinos. The focus lies on describing the physics of neutrino production from pion decay as accurate as possible by including the kinematics of weak decays and Monte Carlo simulations of pp and pγ interactions. We discuss optically thick (to photohadronic interactions) sources, sources of cosmic ray ``nuclei'' and muon damped sources. Even in the proposed upgrade IceCube-Gen2, a discrimination of scenarios such as pp versus pγ is extremely challenging under realistic assumptions. Nonetheless, the Glashow resonance can serve as a smoking gun signature of neutrino production from photohadronic (Aγ) interactions of heavier nuclei, as the expected Glashow event rate exceeds that of pp interactions. We finally quantify the exposures for which the non-observation of Glashow events exerts pressure on certain scenarios.

Fitness landscape transformation through a single amino acid change in the rho terminator.

PubMed

Freddolino, Peter L; Goodarzi, Hani; Tavazoie, Saeed

2012-05-01

Regulatory networks allow organisms to match adaptive behavior to the complex and dynamic contingencies of their native habitats. Upon a sudden transition to a novel environment, the mismatch between the native behavior and the new niche provides selective pressure for adaptive evolution through mutations in elements that control gene expression. In the case of core components of cellular regulation and metabolism, with broad control over diverse biological processes, such mutations may have substantial pleiotropic consequences. Through extensive phenotypic analyses, we have characterized the systems-level consequences of one such mutation (rho*) in the global transcriptional terminator Rho of Escherichia coli. We find that a single amino acid change in Rho results in a massive change in the fitness landscape of the cell, with widely discrepant fitness consequences of identical single locus perturbations in rho* versus rho(WT) backgrounds. Our observations reveal the extent to which a single regulatory mutation can transform the entire fitness landscape of the cell, causing a massive change in the interpretation of individual mutations and altering the evolutionary trajectories which may be accessible to a bacterial population.

Ultra-low field T1 vs. T1rho at 3T and 7T: study of rotationally immobilized protein gels and animal brain tissues

NASA Astrophysics Data System (ADS)

Dong, Hui; Inglis, Ben; Barr, Ian; Clarke, John

2015-03-01

Clinical magnetic resonance imaging (MRI) machines operating in static fields of typically 1.5 T or 3 T can capture information on slow molecular dynamics utilizing the so-called T1rho technique. This technique, in which a radiofrequency (RF) spin-lock field is applied with microtesla amplitude, has been used, for example, to determine the onset time of stroke in studies on rats. The long RF pulse, however, may exceed the specific absorption rate (SAR) limit, putting subjects at risk. Ultra-low-field (ULF) MRI, based on Superconducting Quantum Interference Devices (SQUIDs), directly detects proton signals at a static magnetic field of typically 50-250 μT. Using our ULF MRI system with adjustable static field of typically 55 to 240 μT, we systematically measured the T1 and T2 dispersion profiles of rotationally immobilized protein gels (bovine serum albumin), ex vivo pig brains, and ex vivo rat brains with induced stroke. Comparing the ULF results with T1rho dispersion obtained at 3 T and 7 T, we find that the degree of protein immobilization determines the frequency-dependence of both T1 and T1rho. Furthermore, T1rho and ULF T1 show similar results for stroke, suggesting that ULF MRI may be used to image traumatic brain injury with negligible SAR. This research was supported by the Henry H. Wheeler, Jr. Brain Imaging Center and the Donaldson Trust.

Resonant slepton production yields CMS e e j j and e p Tj j excesses

NASA Astrophysics Data System (ADS)

Allanach, Ben; Biswas, Sanjoy; Mondal, Subhadeep; Mitra, Manimala

2015-01-01

Recent CMS searches for dileptoquark production report local excesses of 2.4 σ in an e e j j channel and 2.6 σ in an e p Tj j channel. Here, we simultaneously explain both excesses with resonant slepton production in R -parity violating supersymmetry. We consider resonant slepton production, which decays to a lepton and a chargino/neutralino, followed by three-body decays of the neutralino/chargino via an R -parity violating coupling. There are regions of parameter space which are also compatible at the 95% confidence level with a 2.8 σ e e j j excess in a recent CMS WR search, while being compatible with other direct search constraints. Phase II of the GERDA neutrinoless double beta decay (0 ν β β ) experiment will probe a sizable portion of the good-fit region.

Transport and thermoelectric properties of Sr{sub 3}(Ti{sub 0.95}R{sub 0.05}){sub 2}O{sub 7} (R = Ta, Nb, W) oxides

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

Sun, R. R.; Qin, X. Y.; Li, L. L.

2012-12-15

The Sr{sub 3}(Ti{sub 0.95}R{sub 0.05}){sub 2}O{sub 7} (R = Ta, Nb, W) polycrystalline compounds were fabricated, and their transport and thermoelectric properties were investigated. The results indicate that at T > 300 K electrical resistivity {rho} for all the doped compounds increases monotonically with temperature, and basically can be described by a relation {rho}{proportional_to}T{sup M} at T > {approx}650 K, with M = 1.39, 1.66, and 1.77 for R = Ta, Nb, and W, respectively, implying that at the high temperatures the acoustic phonon scattering dominates the scattering process. Although the resistivity {rho} of Sr{sub 3}(Ti{sub 0.95}Ta{sub 0.05}){sub 2}O{sub 7}more » exhibits a metallic-like behavior at the temperature as low as 5 K, a transition from metallic state (d{rho}/dT > 0) to semiconductor-like state (d{rho}/dT < 0) was observed at a critical low temperature {approx}41 K and {approx}79 K for R = Nb and W, respectively. At T < {approx}22 K, {approx}57 K, and {approx}80 K, a relation of {sigma}{proportional_to}T{sup 1/2} (here conductivity {sigma} = 1/{rho}) holds for the doped compounds with R = Nb, Ta, and W, respectively, suggesting that at the low temperatures the main transport mechanism is electron-electron interaction due to the presence of disorder induced by the dopants. The thermoelectric figure of merit (ZT) for Ta-doped compound increases more steeply with increasing temperature among the three compounds and reaches 0.066 at 1000 K.« less

RhoA/ROCK signaling regulates smooth muscle phenotypic modulation and vascular remodeling via the JNK pathway and vimentin cytoskeleton.

PubMed

Tang, Lian; Dai, Fan; Liu, Yan; Yu, Xiaoqiang; Huang, Chao; Wang, Yuqin; Yao, Wenjuan

2018-05-20

The RhoA/ROCK signaling pathway regulates cell morphology, adhesion, proliferation, and migration. In this study, we investigated the regulatory role of RhoA/ROCK signaling on PDGF-BB-mediated smooth muscle phenotypic modulation and vascular remodeling and clarified the molecular mechanisms behind these effects. PDGF-BB treatment induced the activation of RhoA, ROCK, PDGF-Rβ, and the expression of PDGF-Rβ in HA-VSMCs (human aortic vascular smooth muscle cells). PDGF-Rβ inhibition and RhoA suppression blocked PDGF-BB-induced RhoA activation and ROCK induction. In addition, PDGF-BB-mediated cell proliferation and migration were suppressed by PDGF-Rβ inhibition, RhoA suppression, and ROCK inhibition, suggesting that PDGF-BB promotes phenotypic modulation of HA-VSMCs by activating the RhoA/ROCK pathway via the PDGF receptor. Moreover, suppressing both ROCK1 and ROCK2 blocked cell cycle progression from G0/G1 to S phase by decreasing the transcription and protein expression of cyclin D1, CDK2, and CDK4 via JNK/c-Jun pathway, thus reducing cell proliferation in PDGF-BB-treated HA-VSMCs. ROCK1 deletion, rather than ROCK2 suppression, significantly inhibited PDGF-BB-induced migration by reducing the expression of vimentin and preventing the remodeling of vimentin and phospho-vimentin. Furthermore, ROCK1 deletion suppressed vimentin by inhibiting the phosphorylation of Smad2/3 and the nuclear translocation of Smad4. These findings suggested that ROCK1 and ROCK2 might play different roles in PDGF-BB-mediated cell proliferation and migration in HA-VSMCs. In addition, PDGF-BB and its receptor participated in neointima formation and vascular remodeling by promoting cell cycle protein expression via the JNK pathway and enhancing vimentin expression in a rat balloon injury model; effects that were inhibited by treatment with fasudil. Together, the results of this study reveal a novel mechanism through which RhoA/ROCK signaling regulates smooth muscle phenotypic modulation and

Triptolide disrupts the actin-based Sertoli-germ cells adherens junctions by inhibiting Rho GTPases expression

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

Wang, Xiang; Zhao, Fang

Triptolide (TP), derived from the medicinal plant Triterygium wilfordii Hook. f. (TWHF), is a diterpene triepoxide with variety biological and pharmacological activities. However, TP has been restricted in clinical application due to its narrow therapeutic window especially in reproductive system. During spermatogenesis, Sertoli cell cytoskeleton plays an essential role in facilitating germ cell movement and cell-cell actin-based adherens junctions (AJ). At Sertoli cell-spermatid interface, the anchoring device is a kind of AJ, known as ectoplasmic specializations (ES). In this study, we demonstrate that β-actin, an important component of cytoskeleton, has been significantly down-regulated after TP treatment. TP can inhibit themore » expression of Rho GTPase such as, RhoA, RhoB, Cdc42 and Rac1. Downstream of Rho GTPase, Rho-associated protein kinase (ROCKs) gene expressions were also suppressed by TP. F-actin immunofluorescence proved that TP disrupts Sertoli cells cytoskeleton network. As a result of β-actin down-regulation, TP treatment increased expression of testin, which indicating ES has been disassembled. In summary, this report illustrates that TP induces cytoskeleton dysfunction and disrupts cell-cell adherens junctions via inhibition of Rho GTPases. - Highlights: • Triptolide induced the disruption of Sertoli-germ cell adherens junction. • Rho GTPases expression and actin dynamics have been suppressed by triptolide. • Actin-based adherens junction is a potential antifertility target of triptolide. • Rho-Rock is involved in the regulation of actin dynamics.« less

Induction of Oligodendrocyte Differentiation and In Vitro Myelination by Inhibition of Rho-Associated Kinase

PubMed Central

Taylor, Christopher; Pereira, Albertina; Seng, Michelle; Tham, Chui-Se; Izrael, Michal; Webb, Michael

2014-01-01

In inflammatory demyelinating diseases such as multiple sclerosis (MS), myelin degradation results in loss of axonal function and eventual axonal degeneration. Differentiation of resident oligodendrocyte precursor cells (OPCs) leading to remyelination of denuded axons occurs regularly in early stages of MS but halts as the pathology transitions into progressive MS. Pharmacological potentiation of endogenous OPC maturation and remyelination is now recognized as a promising therapeutic approach for MS. In this study, we analyzed the effects of modulating the Rho-A/Rho-associated kinase (ROCK) signaling pathway, by the use of selective inhibitors of ROCK, on the transformation of OPCs into mature, myelinating oligodendrocytes. Here we demonstrate, with the use of cellular cultures from rodent and human origin, that ROCK inhibition in OPCs results in a significant generation of branches and cell processes in early differentiation stages, followed by accelerated production of myelin protein as an indication of advanced maturation. Furthermore, inhibition of ROCK enhanced myelin formation in cocultures of human OPCs and neurons and remyelination in rat cerebellar tissue explants previously demyelinated with lysolecithin. Our findings indicate that by direct inhibition of this signaling molecule, the OPC differentiation program is activated resulting in morphological and functional cell maturation, myelin formation, and regeneration. Altogether, we show evidence of modulation of the Rho-A/ROCK signaling pathway as a viable target for the induction of remyelination in demyelinating pathologies. PMID:25289646

Electron spin resonance in the superconducting state of Ba0.6K0.4Fe2As2

NASA Astrophysics Data System (ADS)

Dlamini, Zolile Wiseman; Srinivasan, A.; Ma, Yanwei; Srinivasu, V. V.

2018-05-01

We report the observation of electron spin resonance (ESR) signals in a single crystal of Ba0.6K0.4Fe2As2 grown by self-flux method. We observed two narrow resonant absorption signals at g-values of 4.3 and 1.99. Significantly, these signals are stronger in intensity at 5 K. They become weaker as the temperature is increased and finally vanish at Tc. The resonance at g = 4.3 (signal I) shows different temperature dependence of intensity for parallel and perpendicular orientations of the magnetic field to the iron arsenide plane. However, the resonance at g = 1.99 (signal 2) does not show much difference in temperature dependence of intensity for the two orientations. Further, temperature dependence of the linewidth of the two signals are also different. We propose that these two signals have their origin in fluctuations in the spin system as magnetic fluctuations are believed to be the origin of superconductivity in iron pnictides. Temperature dependence of intensity of signal I is indicative of Fe cluster formation in the scenario of coexistence of spin density wave and superconducting phase for this composition of the crystal.

Measurement of Muon Neutrino Charged Current Single $$\\pi^0$$ Production on Hydrocarbon using MINERvA

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

Altinok, Ozgur

A sample of charged-current single pion production events for the semi- exclusive channel ν µ + CH → µ -π 0 + nucleon(s) has been obtained using neutrino exposures of the MINERvA detector. Differential cross sections for muon momentum, muon production angle, pion momentum, pion production angle, and four-momentum transfer square Q 2 are reported and are compared to a GENIE-based simulation. The cross section versus neutrino energy is also re- ported. The effects of pion final-state interactions on these cross sections are investigated. The effect of baryon resonance suppression at low Q 2 is examined and an event re-weight used by two previous experiments is shown to improve the data versus simulation agreement. The differential cross sections for Q 2 for Eν < 4.0 GeV and E ν ≥ 4.0 GeV are examined and the shapes of these distributions are compared to those from the experiment’smore » $$\\bar{v}$$ µ-CC (π 0) measurement. The polarization of the pπ 0 system is measured and compared to the simulation predictions. The hadronic invariant mass W distribution is examined for evidence of resonance content, and a search is reported for evidence of a two-particle two-hole (2p2h) contribution. All of the differential cross-section measurements of this Thesis are compared with published MINERvA measurements for ν µ-CC (π +) and \\bar{v}$ µ-CC (π 0) processes.« less

Effect of oxidative stress on Rho kinase II and smooth muscle contraction in rat stomach.

PubMed

Al-Shboul, Othman; Mustafa, Ayman

2015-06-01

Recent studies have shown that both Rho kinase signaling and oxidative stress are involved in the pathogenesis of a number of human diseases, such as diabetes mellitus, hypertension, and atherosclerosis. However, very little is known about the effect of oxidative stress on the gastrointestinal (GI) smooth muscle Rho kinase pathway. The aim of the current study was to investigate the effect of oxidative stress on Rho kinase II and muscle contraction in rat stomach. The peroxynitrite donor 3-morpholinosydnonimine (SIN-1), hydrogen peroxide (H2O2), and peroxynitrite were used to induce oxidative stress. Rho kinase II expression and ACh-induced activity were measured in control and oxidant-treated cells via specifically designed enzyme-linked immunosorbent assay (ELISA) and activity assay kits, respectively. Single smooth muscle cell contraction was measured via scanning micrometry in the presence or absence of the Rho kinase blocker, Y-27632 dihydrochloride. All oxidant agents significantly increased ACh-induced Rho kinase II activity without affecting its expression level. Most important, oxidative stress induced by all three agents augmented ACh-stimulated muscle cell contraction, which was significantly inhibited by Y-27632. In conclusion, oxidative stress activates Rho kinase II and enhances contraction in rat gastric muscle, suggesting an important role in GI motility disorders associated with oxidative stress.

Estradiol induces endothelial cell migration and proliferation through estrogen receptor-enhanced RhoA/ROCK pathway.

PubMed

Oviedo, Pilar J; Sobrino, Agua; Laguna-Fernandez, Andrés; Novella, Susana; Tarín, Juan J; García-Pérez, Miguel-Angel; Sanchís, Juan; Cano, Antonio; Hermenegildo, Carlos

2011-03-30

Migration and proliferation of endothelial cells are involved in re-endothelialization and angiogenesis, two important cardiovascular processes that are increased in response to estrogens. RhoA, a small GTPase which controls multiple cellular processes, is involved in the control of cell migration and proliferation. Our aim was to study the role of RhoA on estradiol-induced migration and proliferation and its dependence on estrogen receptors activity. Human umbilical vein endothelial cells were stimulated with estradiol, in the presence or absence of ICI 182780 (estrogen receptors antagonist) and Y-27632 (Rho kinase inhibitor). Estradiol increased Rho GEF-1 gene expression and RhoA (gene and protein expression and activity) in an estrogen receptor-dependent manner. Cell migration, stress fiber formation and cell proliferation were increased in response to estradiol and were also dependent on the estrogen receptors and RhoA activation. Estradiol decreased p27 levels, and significantly raised the expression of cyclins and CDK. These effects were counteracted by the use of either ICI 182780 or Y-27632. In conclusion, estradiol enhances the RhoA/ROCK pathway and increases cell cycle-related protein expression by acting through estrogen receptors. This results in an enhanced migration and proliferation of endothelial cells. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.

The 'invisible hand': regulation of RHO GTPases by RHOGDIs.

PubMed

Garcia-Mata, Rafael; Boulter, Etienne; Burridge, Keith

2011-07-22

The 'invisible hand' is a term originally coined by Adam Smith in The Theory of Moral Sentiments to describe the forces of self-interest, competition and supply and demand that regulate the resources in society. This metaphor continues to be used by economists to describe the self-regulating nature of a market economy. The same metaphor can be used to describe the RHO-specific guanine nucleotide dissociation inhibitor (RHOGDI) family, which operates in the background, as an invisible hand, using similar forces to regulate the RHO GTPase cycle.

The invisible hand: regulation of RHO GTPases by RHOGDIs

PubMed Central

Garcia-Mata, Rafael; Boulter, Etienne; Burridge, Keith

2011-01-01

Preface The 'invisible hand' is a term originally coined by Adam Smith in the Theory of Moral Sentiments to describe the forces of self-interest, competition, and supply and demand that regulate the resources in society. This metaphor continues to be used by economists to describe the self-regulating nature of a market economy. The same metaphor can be used to describe the RHO-specific guanine nucleotide dissociation inhibitor (RHOGDI) family, which operates in the background, as an invisible hand, using similar forces to regulate the RHO GTPase cycle. PMID:21779026

Observed Ωc0 resonances as pentaquark states

NASA Astrophysics Data System (ADS)

An, C. S.; Chen, H.

2017-08-01

In the present work, we investigate the spectrum of several low-lying s s c q q ¯ pentaquark configurations employing the constituent quark model, within which the hyperfine interaction between quarks is taken to be mediated by Goldstone boson exchange. Our numerical results show that four s s c q q ¯ configurations with JP=1 /2- or JP=3 /2- lie at energies very close to the recently observed five Ωc0 states by the LHCb Collaboration; this indicates that the s s c q q ¯ pentaquark configurations may form sizable components of the observed Ωc0 resonances.

Artifacts correction for T1rho imaging with constant amplitude spin-lock

NASA Astrophysics Data System (ADS)

Chen, Weitian

2017-01-01

T1rho imaging with constant amplitude spin-lock is prone to artifacts in the presence of B1 RF and B0 field inhomogeneity. Despite significant technological progress, improvements on the robustness of constant amplitude spin-lock are necessary in order to use it for routine clinical practice. This work proposes methods to simultaneously correct for B1 RF and B0 field inhomogeneity in constant amplitude spin-lock. By setting the maximum B1 amplitude of the excitation adiabatic pulses equal to the expected constant amplitude spin-lock frequency, the spins become aligned along the effective field throughout the spin-lock process. This results in T1rho-weighted images free of artifacts, despite the spatial variation of the effective field caused by B1 RF and B0 field inhomogeneity. When the pulse is long, the relaxation effect during the adiabatic half passage may result in a non-negligible error in the mono-exponential relaxation model. A two-acquisition approach is presented to solve this issue. Simulation, phantom, and in-vivo scans demonstrate the proposed methods achieve superior image quality compared to existing methods, and that the two-acquisition method is effective in resolving the relaxation effect during the adiabatic half passage.

Optogenetic control of RhoA reveals zyxin-mediated elasticity of stress fibres

NASA Astrophysics Data System (ADS)

Oakes, Patrick W.; Wagner, Elizabeth; Brand, Christoph A.; Probst, Dimitri; Linke, Marco; Schwarz, Ulrich S.; Glotzer, Michael; Gardel, Margaret L.

2017-06-01

Cytoskeletal mechanics regulates cell morphodynamics and many physiological processes. While contractility is known to be largely RhoA-dependent, the process by which localized biochemical signals are translated into cell-level responses is poorly understood. Here we combine optogenetic control of RhoA, live-cell imaging and traction force microscopy to investigate the dynamics of actomyosin-based force generation. Local activation of RhoA not only stimulates local recruitment of actin and myosin but also increased traction forces that rapidly propagate across the cell via stress fibres and drive increased actin flow. Surprisingly, this flow reverses direction when local RhoA activation stops. We identify zyxin as a regulator of stress fibre mechanics, as stress fibres are fluid-like without flow reversal in its absence. Using a physical model, we demonstrate that stress fibres behave elastic-like, even at timescales exceeding turnover of constituent proteins. Such molecular control of actin mechanics likely plays critical roles in regulating morphodynamic events.

Deletion of RhoA in Progesterone Receptor-Expressing Cells Leads to Luteal Insufficiency and Infertility in Female Mice.

PubMed

El Zowalaty, Ahmed E; Li, Rong; Zheng, Yi; Lydon, John P; DeMayo, Francesco J; Ye, Xiaoqin

2017-07-01

Ras homolog gene family, member A (RhoA) is widely expressed throughout the female reproductive system. To assess its role in progesterone receptor-expressing cells, we generated RhoA conditional knockout mice RhoAd/d (RhoAf/f-Pgr-Cre+/-). RhoAd/d female mice had comparable mating activity, serum luteinizing hormone, prolactin, and estradiol levels and ovulation with control but were infertile with progesterone insufficiency, indicating impaired steroidogenesis in RhoAd/d corpus luteum (CL). RhoA was highly expressed in wild-type luteal cells and conditionally deleted in RhoAd/d CL. Gestation day 3.5 (D3.5) RhoAd/d ovaries had reduced numbers of CL, less defined corpus luteal cord formation, and disorganized CL collagen IV staining. RhoAd/d CL had lipid droplet and free cholesterol accumulation, indicating the availability of cholesterol for steroidogenesis, but disorganized β-actin and vimentin staining, indicating disrupted cytoskeleton integrity. Cytoskeleton is important for cytoplasmic cholesterol movement to mitochondria and for regulating mitochondria. Dramatically reduced expression of mitochondrial markers heat shock protein 60 (HSP60), voltage-dependent anion channel, and StAR was detected in RhoAd/d CL. StAR carries out the rate-limiting step of steroidogenesis. StAR messenger RNA expression was reduced in RU486-treated D3.5 wild-type CL and tended to be induced in progesterone-treated D3.5 RhoAd/d CL, with parallel changes of HSP60 expression. These data demonstrated the in vivo function of RhoA in CL luteal cell cytoskeleton integrity, cholesterol transport, StAR expression, and progesterone synthesis, and a positive feedback on StAR expression in CL by progesterone signaling. These findings provide insights into mechanisms of progesterone insufficiency.

Activator-inhibitor coupling between Rho signaling and actin assembly make the cell cortex an excitable medium

PubMed Central

Bement, William M.; Leda, Marcin; Moe, Alison M.; Kita, Angela M.; Larson, Matthew E.; Golding, Adriana E.; Pfeuti, Courtney; Su, Kuan-Chung; Miller, Ann L.; Goryachev, Andrew B.; von Dassow, George

2016-01-01

Animal cell cytokinesis results from patterned activation of the small GTPase Rho, which directs assembly of actomyosin in the equatorial cortex. Cytokinesis is restricted to a portion of the cell cycle following anaphase onset in which the cortex is responsive to signals from the spindle. We show that shortly after anaphase onset oocytes and embryonic cells of frogs and echinoderms exhibit cortical waves of Rho activity and F-actin polymerization. The waves are modulated by cyclin-dependent kinase 1 (Cdk1) activity and require the Rho GEF (guanine nucleotide exchange factor), Ect2. Surprisingly, during wave propagation, while Rho activity elicits F-actin assembly, F-actin subsequently inactivates Rho. Experimental and modeling results show that waves represent excitable dynamics of a reaction diffusion system with Rho as the activator and F-actin the inhibitor. We propose that cortical excitability explains fundamental features of cytokinesis including its cell cycle regulation. PMID:26479320

Interaction of Myosin Phosphatase Target Subunit (MYPT1) with Myosin Phosphatase-RhoA Interacting Protein (MRIP): A Role of Glutamic Acids in the Interaction.

PubMed

Lee, Eunhee; Stafford, Walter F

2015-01-01

Scaffold proteins bind to and functionally link protein members of signaling pathways. Interaction of the scaffold proteins, myosin phosphatase target subunit (MYPT1) and myosin phosphatase-RhoA interacting protein (MRIP), causes co-localization of myosin phosphatase and RhoA to actomyosin. To examine biophysical properties of interaction of MYPT1 with MRIP, we employed analytical ultracentrifugation and surface plasmon resonance. In regard to MRIP, its residues 724-837 are sufficient for the MYPT1/MRIP interaction. Moreover, MRIP binds to MYPT1 as either a monomer or a dimer. With respect to MYPT1, its leucine repeat region, LR (residues 991-1030) is sufficient to account for the MYPT1/MRIP interaction. Furthermore, point mutations that replace glutamic acids 998-1000 within LR reduced the binding affinity toward MRIP. This suggests that the glutamic acids of MYPT1 play an important role in the interaction.

A High-Throughput Assay for Rho Guanine Nucleotide Exchange Factors Based on the Transcreener GDP Assay.

PubMed

Reichman, Melvin; Schabdach, Amanda; Kumar, Meera; Zielinski, Tom; Donover, Preston S; Laury-Kleintop, Lisa D; Lowery, Robert G

2015-12-01

Ras homologous (Rho) family GTPases act as molecular switches controlling cell growth, movement, and gene expression by cycling between inactive guanosine diphosphate (GDP)- and active guanosine triphosphate (GTP)-bound conformations. Guanine nucleotide exchange factors (GEFs) positively regulate Rho GTPases by accelerating GDP dissociation to allow formation of the active, GTP-bound complex. Rho proteins are directly involved in cancer pathways, especially cell migration and invasion, and inhibiting GEFs holds potential as a therapeutic strategy to diminish Rho-dependent oncogenesis. Methods for measuring GEF activity suitable for high-throughput screening (HTS) are limited. We developed a simple, generic biochemical assay method for measuring GEF activity based on the fact that GDP dissociation is generally the rate-limiting step in the Rho GTPase catalytic cycle, and thus addition of a GEF causes an increase in steady-state GTPase activity. We used the Transcreener GDP Assay, which relies on selective immunodetection of GDP, to measure the GEF-dependent stimulation of steady-state GTP hydrolysis by small GTPases using Dbs (Dbl's big sister) as a GEF for Cdc42, RhoA, and RhoB. The assay is well suited for HTS, with a homogenous format and far red fluorescence polarization (FP) readout, and it should be broadly applicable to diverse Rho GEF/GTPase pairs. © 2015 Society for Laboratory Automation and Screening.

Coupled channel analysis of overlinepp annihilation into π0π0π0, π0ηη and π0π0η

NASA Astrophysics Data System (ADS)

Amsler, C.; Armstrong, D. S.; Baker, C. A.; Barnett, B. M.; Batty, C. J.; Benayoun, M.; Beuchert, K.; Birien, P.; Blüm, P.; Bossingham, R.; Braune, K.; Brose, J.; Bugg, D. V.; Case, T.; Chung, S. U.; Cooper, A. R.; Cramer, O.; Crowe, K. M.; Degener, T.; Dietz, H. P.; Djaoshvili, N.; Dombroski, S. v.; Doser, M.; Dünnweber, W.; Engelhardt, D.; Englert, M.; Faessler, M. A.; Felix, C.; Giarritta, P.; Hackmann, R.; Haddock, R. P.; Heinsius, F. H.; Herz, M.; Hessey, N. P.; Hidas, P.; Holzhaussen, C.; Illinger, P.; Jamnik, D.; Kalinowsky, H.; Kalteyer, B.; Kämmle, B.; Kiel, T.; Kisiel, J.; Klempt, E.; Koch, H.; Kobel, M.; Kolo, C.; Kunze, M.; Lakata, M.; Landua, R.; Lüdemann, J.; Matthäy, H.; McCrady, R.; Merlo, J. P.; Meyer, C. A.; Montanet, L.; Noble, A.; Ouared, R.; Ould-Saada, F.; Peters, K.; Pinder, C. N.; Pinter, G.; Ravndal, S.; Regenfus, C.; Schäfer, E.; Schmidt, P.; Schütrumpf, M.; Seibert, R.; Spanier, S.; Stöck, H.; Straßburger, C.; Strohbusch, U.; Suffert, M.; Thoma, U.; Tischhäuser, M.; Urner, D.; Völcker, C.; Walter, F.; Walther, D.; Wiedner, U.; Winter, N.; Zoll, J.; Zou, B. S.; Zupančič, Č.; Crystal Barrel Collaboration

1995-02-01

We confirm the existence of the two IG( JPC) = 0 +(0 ++) resonances f0(1370) and f0(1500) reported by us in earlier analyses. The analysis presented here couples the final states π0π0π0, π0π0η and π0ηη of overlinepp annihilation at rest. It is based on a 3 × 3 K-matrix. We find masses and widths of M = (1390±30) MeV, Γ = (380±80) MeV; and M = (1500±10) MeV, Γ = (154 ± 30) MeV, respectively. The product branching ratios for the production and decay into π0π0 and ηη of the f 0(1500) are (1.27 ± 0.33) · 10 -3 and (0.60 ± 0.17) · 10 -3, respectively.

Macrophage differentiation induced by PMA is mediated by activation of RhoA/ROCK signaling.

PubMed

Yang, Lifeng; Dai, Fan; Tang, Lian; Le, Yulan; Yao, Wenjuan

2017-01-01

In order to investigate the effects of RhoA/ROCK signaling in macrophage differentiation, we used 100 ng/mL PMA to induce macrophage differentiation from U937 cells in vitro. The observation of cell morphology and the expression of CD68 and SR-A were performed to confirm the differentiation induced by PMA. Western blot analysis showed that the expression of ROCK1 and ROCK2 and the phosphorylation of MYPT1 were significantly increased after PMA treatment. Pulldown assay showed that the activation of RhoA was obviously enhanced when U937 cells were treated with PMA. In order to further demonstrate whether RhoA/ROCK signaling could mediate the macrophage differentiation induced by PMA, we successfully suppressed the expression of RhoA, ROCK1 and ROCK2 by performing siRNA technology in U937 cells, respectively. The macrophage differentiation and the expression of CD68 and SR-A were significantly inhibited by the suppression of RhoA, ROCK1 or ROCK2 in PMA-induced U937 cells, indicating that the macrophage differentiation induced by PMA is associated with RhoA/ROCK signaling pathway. In addition, we pretreated U937 cells with Y27632 (ROCK inhibitor, 20 μM) for 30 min and then observed the macrophage differentiation induced by PMA. The result illustrated that Y27632 pretreatment obviously inhibited PMA-induced differentiation and the expression of CD68 and SR-A. In conclusion, the activation of RhoA/ROCK signaling is responsible for the macrophage differentiation induced by PMA.

Activation of RhoA by Lysophosphatidic Acid and Gα12/13 Subunits in Neuronal Cells: Induction of Neurite Retraction

PubMed Central

Kranenburg, Onno; Poland, Mieke; van Horck, Francis P. G.; Drechsel, David; Hall, Alan; Moolenaar, Wouter H.

1999-01-01

Neuronal cells undergo rapid growth cone collapse, neurite retraction, and cell rounding in response to certain G protein–coupled receptor agonists such as lysophosphatidic acid (LPA). These shape changes are driven by Rho-mediated contraction of the actomyosin-based cytoskeleton. To date, however, detection of Rho activation has been hampered by the lack of a suitable assay. Furthermore, the nature of the G protein(s) mediating LPA-induced neurite retraction remains unknown. We have developed a Rho activation assay that is based on the specific binding of active RhoA to its downstream effector Rho-kinase (ROK). A fusion protein of GST and the Rho-binding domain of ROK pulls down activated but not inactive RhoA from cell lysates. Using GST-ROK, we show that in N1E-115 neuronal cells LPA activates endogenous RhoA within 30 s, concomitant with growth cone collapse. Maximal activation occurs after 3 min when neurite retraction is complete and the actin cytoskeleton is fully contracted. LPA-induced RhoA activation is completely inhibited by tyrosine kinase inhibitors (tyrphostin 47 and genistein). Activated Gα12 and Gα13 subunits mimic LPA both in activating RhoA and in inducing RhoA-mediated cytoskeletal contraction, thereby preventing neurite outgrowth. We conclude that in neuronal cells, LPA activates RhoA to induce growth cone collapse and neurite retraction through a G12/13-initiated pathway that involves protein-tyrosine kinase activity. PMID:10359601

Resonant production of dark photons in positron beam dump experiments

NASA Astrophysics Data System (ADS)

Nardi, Enrico; Carvajal, Cristian D. R.; Ghoshal, Anish; Meloni, Davide; Raggi, Mauro

2018-05-01

Positrons beam dump experiments have unique features to search for very narrow resonances coupled superweakly to e+e- pairs. Due to the continued loss of energy from soft photon bremsstrahlung, in the first few radiation lengths of the dump a positron beam can continuously scan for resonant production of new resonances via e+ annihilation off an atomic e- in the target. In the case of a dark photon A' kinetically mixed with the photon, this production mode is of first order in the electromagnetic coupling α , and thus parametrically enhanced with respect to the O (α2)e+e-→γ A' production mode and to the O (α3)A' bremsstrahlung in e- -nucleon scattering so far considered. If the lifetime is sufficiently long to allow the A' to exit the dump, A'→e+e- decays could be easily detected and distinguished from backgrounds. We explore the foreseeable sensitivity of the Frascati PADME experiment in searching with this technique for the 17 MeV dark photon invoked to explain the Be 8 anomaly in nuclear transitions.

Significance of Pathways Leading to RhoC Overexpression in Breast Cancer

DTIC Science & Technology

2008-04-01

relationship of RhoC and NF-kappa B to aggressive, metastatic, and therapy-resistant breast cancer. Inflammation is currently being considered a key...scored the initial TMA for EZH2 (Polycomb group protein Enhancer of zeste-2) and found a significant relationship with estrogen and progesterone... relationship of RhoC and NF-kappa B expression to aggressive tumors while controlling for demographics and treatment. EPIDEMIOLOGY

Sex differences in the enhanced responsiveness to acute angiotensin II in growth-restricted rats: role of fasudil, a Rho kinase inhibitor

PubMed Central

Ojeda, Norma B.; Royals, Thomas P.

2013-01-01

This study tested the hypothesis that Rho kinase contributes to the enhanced pressor response to acute angiotensin II in intact male growth-restricted and gonadectomized female growth-restricted rats. Mean arterial pressure (MAP) and renal function were determined in conscious animals pretreated with enalapril (250 mg/l in drinking water) for 1 wk to block the endogenous renin-angiotensin system and normalize blood pressure (baseline). Blood pressure and renal hemodynamics did not differ at baseline. Acute Ang II (100 ng·kg−1·min−1) induced a greater increase in MAP and renal vascular resistance and enhanced reduction in glomerular filtration rate in intact male growth-restricted rats compared with intact male controls (P < 0.05). Cotreatment with the Rho kinase inhibitor fasudil (33 μg·kg−1·min−1) significantly attenuated these hemodynamic changes (P < 0.05), but it did not abolish the differential increase in blood pressure above baseline, suggesting that the impact of intrauterine growth restriction on blood pressure in intact male growth-restricted rats is independent of Rho kinase. Gonadectomy in conjunction with fasudil returned blood pressure back to baseline in male growth-restricted rats, and yet glomerular filtration rate remained significantly reduced (P < 0.05). Thus, these data suggest a role for enhanced renal sensitivity to acute Ang II in the developmental programming of hypertension in male growth-restricted rats. However, inhibition of Rho kinase had no effect on the basal or enhanced increase in blood pressure induced by acute Ang II in the gonadectomized female growth-restricted rat. Therefore, these studies suggest that Rho kinase inhibition exerts a sex-specific effect on blood pressure sensitivity to acute Ang II in growth-restricted rats. PMID:23344570

Sex differences in the enhanced responsiveness to acute angiotensin II in growth-restricted rats: role of fasudil, a Rho kinase inhibitor.

PubMed

Ojeda, Norma B; Royals, Thomas P; Alexander, Barbara T

2013-04-01

This study tested the hypothesis that Rho kinase contributes to the enhanced pressor response to acute angiotensin II in intact male growth-restricted and gonadectomized female growth-restricted rats. Mean arterial pressure (MAP) and renal function were determined in conscious animals pretreated with enalapril (250 mg/l in drinking water) for 1 wk to block the endogenous renin-angiotensin system and normalize blood pressure (baseline). Blood pressure and renal hemodynamics did not differ at baseline. Acute Ang II (100 ng·kg(-1)·min(-1)) induced a greater increase in MAP and renal vascular resistance and enhanced reduction in glomerular filtration rate in intact male growth-restricted rats compared with intact male controls (P < 0.05). Cotreatment with the Rho kinase inhibitor fasudil (33 μg·kg(-1)·min(-1)) significantly attenuated these hemodynamic changes (P < 0.05), but it did not abolish the differential increase in blood pressure above baseline, suggesting that the impact of intrauterine growth restriction on blood pressure in intact male growth-restricted rats is independent of Rho kinase. Gonadectomy in conjunction with fasudil returned blood pressure back to baseline in male growth-restricted rats, and yet glomerular filtration rate remained significantly reduced (P < 0.05). Thus, these data suggest a role for enhanced renal sensitivity to acute Ang II in the developmental programming of hypertension in male growth-restricted rats. However, inhibition of Rho kinase had no effect on the basal or enhanced increase in blood pressure induced by acute Ang II in the gonadectomized female growth-restricted rat. Therefore, these studies suggest that Rho kinase inhibition exerts a sex-specific effect on blood pressure sensitivity to acute Ang II in growth-restricted rats.

The effect of butylphthalide on the brain edema, blood-brain barrier of rats after focal cerebral infarction and the expression of Rho A.

PubMed

Hu, Jinyang; Wen, Qingping; Wu, Yue; Li, Baozhu; Gao, Peng

2014-06-01

The aim of this study was to explore the effect of butylphthalide on the brain edema, blood-brain barrier of rats of rats after focal cerebral infarction and the expression of Rho A. A total of 195 sprague-dawley male rats were randomly divided into control group, model group, and butylphthalide group (40 mg/kg, once a day, by gavage). The model was made by photochemical method. After surgery 3, 12, 24, 72, and 144 h, brain water content was done to see the effect of butylphthalide for the cerebral edema. Evans blue extravasation method was done to see the changes in blood-brain barrier immunohistochemistry, and Western blot was done to see the expression of Rho A around the infarction. Compared with the control group, the brain water content of model group and butylphthalide group rats was increased, the permeability of blood-brain barrier of model group and butylphthalide group rats was increased, and the Rho A protein of model group and butylphthalide group rats was increased. Compared with the model group, the brain water content of butylphthalide group rats was induced (73.67 ± 0.67 vs 74.14 ± 0.46; 74.89 ± 0.57 vs 75.61 ± 0.52; 77.49 ± 0.34 vs 79.33 ± 0.49; 76.31 ± 0.56 vs 78.01 ± 0.48; 72.36 ± 0.44 vs 73.12 ± 0.73; P < 0.05), the permeability of blood-brain barrier of butylphthalide group rats was induced (319.20 ± 8.11 vs 394.60 ± 6.19; 210.40 ± 9.56 vs 266.40 ± 7.99; 188.00 ± 9.22 vs 232.40 ± 7.89; 288.40 ± 7.86 vs 336.00 ± 6.71; 166.60 ± 6.23 vs 213.60 ± 13.79; P < 0.05), and the Rho A protein of butylphthalide group rats was decreased (western blot result: 1.2230 ± 0.0254 vs 1.3970 ± 0.0276; 1.5985 ± 0.0206 vs 2.0368 ± 0.0179; 1.4229 ± 0.0167 vs 1.7930 ± 0.0158;1.3126 ± 0.0236 vs 1.5471 ± 0.0158; P < 0.05). The butylphthalide could reduce the brain edema, protect the blood-brain barrier, and decrease the expression of Rho A around the infarction.

Connecting physical resonant amplitudes and lattice QCD

DOE PAGES

Bolton, Daniel R.; Briceno, Raul A.; Wilson, David J.

2016-03-18

Here, we present a determination of the isovector,more » $P$-wave $$\\pi\\pi$$ scattering phase shift obtained by extrapolating recent lattice QCD results from the Hadron Spectrum Collaboration using $$m_\\pi =236$$ MeV. The finite volume spectra are described using extensions of L\\"uscher's method to determine the infinite volume Unitarized Chiral Perturbation Theory scattering amplitude. We exploit the pion mass dependence of this effective theory to obtain the scattering amplitude at $$m_\\pi= 140$$ MeV. The scattering phase shift is found to be in good agreement with experiment up to center of mass energies of 1.2 GeV. The analytic continuation of the scattering amplitude to the complex plane yields a $$\\rho$$-resonance pole at $$E_\\rho= \\left[755(2)(1)(^{20}_{02})-\\frac{i}{2}\\,129(3)(1)(^{7}_{1})\\right]~{\\rm MeV}$$. The techniques presented illustrate a possible pathway towards connecting lattice QCD observables of few-body, strongly interacting systems to experimentally accessible quantities.« less

Expected accuracy in a measurement of the CKM angle alpha using a Dalitz plot analysis of B0 ---> rho pi decays in the BTeV project

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

Shestermanov, K.E.; Vasiliev, A.N; /Serpukhov, IHEP

2005-12-01

A precise measurement of the angle {alpha} in the CKM triangle is very important for a complete test of Standard Model. A theoretically clean method to extract {alpha} is provided by B{sup 0} {yields} {rho}{pi} decays. Monte Carlo simulations to obtain the BTeV reconstruction efficiency and to estimate the signal to background ratio for these decays were performed. Finally the time-dependent Dalitz plot analysis, using the isospin amplitude formalism for tre and penguin contributions, was carried out. It was shown that in one year of data taking BTeV could achieve an accuracy on {alpha} better than 5{sup o}.

The balance between Gαi-Cdc42/Rac and Gα12/13-RhoA pathways determines endothelial barrier regulation by sphingosine-1-phosphate

PubMed Central

Reinhard, Nathalie R.; Mastop, Marieke; Yin, Taofei; Wu, Yi; Bosma, Esmeralda K.; Gadella, Theodorus W. J.; Goedhart, Joachim; Hordijk, Peter L.

2017-01-01

The bioactive sphingosine-1-phosphatephosphate (S1P) is present in plasma, bound to carrier proteins, and involved in many physiological processes, including angiogenesis, inflammatory responses, and vascular stabilization. S1P can bind to several G-protein–coupled receptors (GPCRs) activating a number of different signaling networks. At present, the dynamics and relative importance of signaling events activated immediately downstream of GPCR activation are unclear. To examine these, we used a set of fluorescence resonance energy transfer–based biosensors for different RhoGTPases (Rac1, RhoA/B/C, and Cdc42) as well as for heterotrimeric G-proteins in a series of live-cell imaging experiments in primary human endothelial cells. These experiments were accompanied by biochemical GTPase activity assays and transendothelial resistance measurements. We show that S1P promotes cell spreading and endothelial barrier function through S1PR1-Gαi-Rac1 and S1PR1-Gαi-Cdc42 pathways. In parallel, a S1PR2-Gα12/13-RhoA pathway is activated that can induce cell contraction and loss of barrier function, but only if Gαi-mediated signaling is suppressed. Our results suggest that Gαq activity is not involved in S1P-mediated regulation of barrier integrity. Moreover, we show that early activation of RhoA by S1P inactivates Rac1 but not Cdc42, and vice versa. Together, our data show that the rapid S1P-induced increase in endothelial integrity is mediated by a S1PR1-Gαi-Cdc42 pathway. PMID:28954861

The role of the RhoA/ROCK pathway in gender-dependent differences in gastric smooth muscle contraction.

PubMed

Al-Shboul, Othman

2016-01-01

Gender-related differences in various gastric functions and diseases have been reported, with women having a higher prevalence of gastrointestinal disturbances than men. The aim of this study was to investigate sex-dependent differences in activation of the Rho-associated protein kinase (ROCK; RhoA/Rho kinase) pathway and muscle contraction in the stomach using single gastric smooth muscle cells (GSMC) from male and female Sprague-Dawley rats. Expression of ROCK1 and ROCK2 protein and acetylcholine (ACh)-induced activation of RhoA and ROCK were measured using a specifically designed enzyme-linked immunosorbent assay and activity assay kits, respectively. Contraction of a single GSMC was measured by scanning micrometry in the presence or absence of the ROCK inhibitor Y27632 dihydrochloride. ACh-induced activation of RhoA and ROCK and subsequent contraction were greater in male rats than in female rats but neither was related to differences in the expression of ROCK1 or ROCK2 or total RhoA amount. Most important, Y27632 inhibited and abolished differences in ACh-induced contraction in both sexes. In conclusion, increased ACh-induced contraction in the GSMC of male rats is attributable to greater RhoA/ROCK activation independent of differences in the expression of ROCK isoforms or total RhoA.

RhoB controls coordination of adult angiogenesis and lymphangiogenesis following injury by regulating VEZF1-mediated transcription

NASA Astrophysics Data System (ADS)

Gerald, Damien; Adini, Irit; Shechter, Sharon; Perruzzi, Carole; Varnau, Joseph; Hopkins, Benjamin; Kazerounian, Shiva; Kurschat, Peter; Blachon, Stephanie; Khedkar, Santosh; Bagchi, Mandrita; Sherris, David; Prendergast, George C.; Klagsbrun, Michael; Stuhlmann, Heidi; Rigby, Alan C.; Nagy, Janice A.; Benjamin, Laura E.

2013-11-01

Mechanisms governing the distinct temporal dynamics that characterize post-natal angiogenesis and lymphangiogenesis elicited by cutaneous wounds and inflammation remain unclear. RhoB, a stress-induced small GTPase, modulates cellular responses to growth factors, genotoxic stress and neoplastic transformation. Here we show, using RhoB null mice, that loss of RhoB decreases pathological angiogenesis in the ischaemic retina and reduces angiogenesis in response to cutaneous wounding, but enhances lymphangiogenesis following both dermal wounding and inflammatory challenge. We link these unique and opposing roles of RhoB in blood versus lymphatic vasculatures to the RhoB-mediated differential regulation of sprouting and proliferation in primary human blood versus lymphatic endothelial cells. We demonstrate that nuclear RhoB-GTP controls expression of distinct gene sets in each endothelial lineage by regulating VEZF1-mediated transcription. Finally, we identify a small-molecule inhibitor of VEZF1-DNA interaction that recapitulates RhoB loss in ischaemic retinopathy. Our findings establish the first intra-endothelial molecular pathway governing the phased response of angiogenesis and lymphangiogenesis following injury.

Viral vector-mediated downregulation of RhoA increases survival and axonal regeneration of retinal ganglion cells

PubMed Central

Koch, Jan Christoph; Tönges, Lars; Michel, Uwe; Bähr, Mathias; Lingor, Paul

2014-01-01

The Rho/ROCK pathway is a promising therapeutic target in neurodegenerative and neurotraumatic diseases. Pharmacological inhibition of various pathway members has been shown to promote neuronal regeneration and survival. However, because pharmacological inhibitors are inherently limited in their specificity, shRNA-mediated approaches can add more information on the function of each single kinase involved. Thus, we generated adeno-associated viral vectors (AAV) to specifically downregulate Ras homologous member A (RhoA) via shRNA. We found that specific knockdown of RhoA promoted neurite outgrowth of retinal ganglion cells (RGC) grown on the inhibitory substrate chondroitin sulfate proteoglycan (CSPG) as well as neurite regeneration of primary midbrain neurons (PMN) after scratch lesion. In the rat optic nerve crush (ONC) model in vivo, downregulation of RhoA significantly enhanced axonal regeneration compared to control. Moreover, survival of RGC transduced with AAV expressing RhoA-shRNA was substantially increased at 2 weeks after optic nerve axotomy. Compared to previous data using pharmacological inhibitors to target RhoA, its upstream regulator Nogo or its main downstream target ROCK, the specific effects of RhoA downregulation shown here were most pronounced in regard to promoting RGC survival but neurite outgrowth and axonal regeneration were also increased significantly. Taken together, we show here that specific knockdown of RhoA substantially increases neuronal survival after optic nerve axotomy and modestly increases neurite outgrowth in vitro and axonal regeneration after optic nerve crush. PMID:25249936

Detection of Metastatic Potential in Breast Cancer by RhoC-GTPase and WISP3 Proteins

DTIC Science & Technology

2007-05-01

De A, Gambhir SV, Merajver SD, Kolodney MS. Atorvastatin Prevents RhoC Isoprenylation, Invasion and Metastasis in Human Melanoma Cells. Molecular...3-hydroxy-3- methylglutaryl-CoA) reductase inhibitors (statins). In particular, atorvastatin has been clearly shown to inhibit RhoC driven phenotypes...Gambhir SS, Merajver SD, Kolodney MS: Atorvastatin prevents RhoC isoprenylation, inva- sion, and metastasis in human melanoma cells Mol Cancer Ther 2: 941

Use of Synthetic Isoprenoids to Target Protein Prenylation and Rho GTPases in Breast Cancer Invasion

PubMed Central

Chen, Min; Knifley, Teresa; Subramanian, Thangaiah; Spielmann, H. Peter; O’Connor, Kathleen L.

2014-01-01

Dysregulation of Ras and Rho family small GTPases drives the invasion and metastasis of multiple cancers. For their biological functions, these GTPases require proper subcellular localization to cellular membranes, which is regulated by a series of post-translational modifications that result in either farnesylation or geranylgeranylation of the C-terminal CAAX motif. This concept provided the rationale for targeting farnesyltransferase (FTase) and geranylgeranyltransferases (GGTase) for cancer treatment. However, the resulting prenyl transferase inhibitors have not performed well in the clinic due to issues with alternative prenylation and toxicity. As an alternative, we have developed a unique class of potential anti-cancer therapeutics called Prenyl Function Inhibitors (PFIs), which are farnesol or geranyl-geraniol analogs that act as alternate substrates for FTase or GGTase. Here, we test the ability of our lead PFIs, anilinogeraniol (AGOH) and anilinofarnesol (AFOH), to block the invasion of breast cancer cells. We found that AGOH treatment effectively decreased invasion of MDA-MB-231 cells in a two-dimensional (2D) invasion assay at 100 µM while it blocked invasive growth in three-dimensional (3D) culture model at as little as 20 µM. Notably, the effect of AGOH on 3D invasive growth was phenocopied by electroporation of cells with C3 exotransferase. To determine if RhoA and RhoC were direct targets of AGOH, we performed Rho activity assays in MDA-MB-231 and MDA-MB-468 cells and found that AGOH blocked RhoA and RhoC activation in response to LPA and EGF stimulation. Notably, the geranylgeraniol analog AFOH was more potent than AGOH in inhibiting RhoA and RhoC activation and invasive growth. Interestingly, neither AGOH nor AFOH impacted 3D growth of MCF10A cells. Collectively, this study demonstrates that AGOH and AFOH dramatically inhibit breast cancer invasion, at least in part by blocking Rho function, thus, suggesting that targeting prenylation by using

Rho-Kinase Inhibition During Early Cardiac Development Causes Arrhythmogenic Right Ventricular Cardiomyopathy in Mice.

PubMed

Ellawindy, Alia; Satoh, Kimio; Sunamura, Shinichiro; Kikuchi, Nobuhiro; Suzuki, Kota; Minami, Tatsuro; Ikeda, Shohei; Tanaka, Shinichi; Shimizu, Toru; Enkhjargal, Budbazar; Miyata, Satoshi; Taguchi, Yuhto; Handoh, Tetsuya; Kobayashi, Kenta; Kobayashi, Kazuto; Nakayama, Keiko; Miura, Masahito; Shimokawa, Hiroaki

2015-10-01

Arrhythmogenic right ventricular cardiomyopathy (ARVC) is characterized by fibrofatty changes of the right ventricle, ventricular arrhythmias, and sudden death. Though ARVC is currently regarded as a disease of the desmosome, desmosomal gene mutations have been identified only in half of ARVC patients, suggesting the involvement of other associated mechanisms. Rho-kinase signaling is involved in the regulation of intracellular transport and organizes cytoskeletal filaments, which supports desmosomal protein complex at the myocardial cell-cell junctions. Here, we explored whether inhibition of Rho-kinase signaling is involved in the pathogenesis of ARVC. Using 2 novel mouse models with SM22α- or αMHC-restricted overexpression of dominant-negative Rho-kinase, we show that mice with Rho-kinase inhibition in the developing heart (SM22α-restricted) spontaneously develop cardiac dilatation and dysfunction, myocardial fibrofatty changes, and ventricular arrhythmias, resulting in premature sudden death, phenotypes fulfilling the criteria of ARVC in humans. Rho-kinase inhibition in the developing heart results in the development of ARVC phenotypes in dominant-negative Rho-kinase mice through 3 mechanisms: (1) reduction of cardiac cell proliferation and ventricular wall thickness, (2) stimulation of the expression of the proadipogenic noncanonical Wnt ligand, Wnt5b, and the major adipogenic transcription factor, PPARγ (peroxisome proliferator activated receptor-γ), and inhibition of Wnt/β-catenin signaling, and (3) development of desmosomal abnormalities. These mechanisms lead to the development of cardiac dilatation and dysfunction, myocardial fibrofatty changes, and ventricular arrhythmias, ultimately resulting in sudden premature death in this ARVC mouse model. This study demonstrates a novel crucial role of Rho-kinase inhibition during cardiac development in the pathogenesis of ARVC in mice. © 2015 American Heart Association, Inc.

Hair product artifact in magnetic resonance imaging.

PubMed

Chenji, Sneha; Wilman, Alan H; Mah, Dennell; Seres, Peter; Genge, Angela; Kalra, Sanjay

2017-01-01

The presence of metallic compounds in facial cosmetics and permanent tattoos may affect the quality of magnetic resonance imaging. We report a case study describing a signal artifact due to the use of a leave-on powdered hair dye. On reviewing the ingredients of the product, it was found to contain several metallic compounds. In lieu of this observation, we suggest that MRI centers include the use of metal- or mineral-based facial cosmetics or hair products in their screening protocols. Copyright © 2016 Elsevier Inc. All rights reserved.

Involvement of PI3K, Akt, and RhoA in oestradiol regulation of cardiac iNOS expression.

PubMed

Zafirovic, Sonja; Sudar-Milovanovic, Emina; Obradovic, Milan; Djordjevic, Jelena; Jasnic, Nebojsa; Borovic, Milica Labudovic; Isenovic, Esma R

2018-02-12

Oestradiol is an important regulatory factor with several positive effects on the cardiovascular (CV) system. We evaluated the molecular mechanism of the in vivo effects of oestradiol on the regulation of cardiac inducible nitric oxide (NO) synthase (iNOS) expression and activity. Male Wistar rats were treated with oestradiol (40 mg/kg, intraperitoneally) and after 24 h the animals were sacrificed. The concentrations of NO and L-Arginine (L-Arg) were determined spectrophotometrically. For protein expressions of iNOS, p65 subunit of nuclear factor-κB (NFκB-p65), Ras homolog gene family-member A (RhoA), angiotensin II receptor type 1 (AT1R), insulin receptor substrate 1 (IRS-1), p85, p110 and protein kinase B (Akt), Western blot method was used. Co-immunoprecipitation was used for measuring the association of IRS-1 with the p85 subunit of phosphatidylinositol-3-kinase (PI3K). The expression of iNOS messenger ribonucleic acid (mRNA) was measured with the quantitative real-time polymerase chain reaction (qRT-PCR). Immunohistochemical analysis of the tissue was used to detect localization and expression of iNOS in heart tissue. Oestradiol treatment reduced L-Arg concentration (p<0.01), iNOS mRNA (p<0.01) and protein (p<0.001) expression, level of RhoA (p<0.05) and AT1R (p<0.001) protein. In contrast, plasma NO (p<0.05), Akt phosphorylation at Thr308 (p<0.05) and protein level of p85 (p<0.001) increased after oestradiol treatment. Our results suggest that oestradiol in vivo regulates cardiac iNOS expression via the PI3K/Akt signaling pathway, through attenuation of RhoA and AT1R. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Search for resonant $$ \\mathrm{t}\\overline{\\mathrm{t}} $$ production in lepton+jets events in pp collisions at $$ \\sqrt{s}=7 $$ TeV

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

Chatrchyan, S.; Khachatryan, V.; Sirunyan, A. M.

A model-independent search for the production of heavy resonances decaying into top-antitop quark pairs is presented. The search is based on events containing one lepton (muon or electron) and at least two jets selected from data samples corresponding to an integrated luminosity of 4.4-5.0 inverse femtobarns collected in pp collisions at sqrt(s) = 7 TeV. Results are presented from the combination of two dedicated searches optimized for boosted production and production at threshold. No excess of events is observed over the expected yield from the standard model processes. Topcolor Z' bosons with narrow (wide) width are excluded at 95% confidencemore » level for masses below 1.49 (2.04) TeV and an upper limit of 0.3 (1.3) pb or lower is set on the production cross section times branching fraction for resonance masses above 1 TeV. Kaluza-Klein excitations of a gluon with masses below 1.82 TeV (at 95% confidence level) in the Randall-Sundrum model are also excluded, and an upper limit of 0.7 pb or lower is set on the production cross section times branching fraction for resonance masses above 1 TeV.« less

Upregulated STAT3 and RhoA signaling in colorectal cancer (CRC) regulate the invasion and migration of CRC cells.

PubMed

Zhang, G-Y; Yang, W-H; Chen, Z

2016-05-01

We aimed to reveal the expression and activation of signal transducers and activators of transcription 3 (STAT3) and RhoA/Rho-associated coiled-coil forming kinase 1 (ROCK1) signaling in CRC tissues, and to investigate the regulatory role of STAT3 and RhoA signaling in the invasion and migration of colorectal cancer cells. We examined the expression of STAT3, RhoA and ROCK1 in CRC tissues with real-time PCR and Western blotting methods. And then we examined the interaction between STAT3 and RhoA/ROCK1 signaling in CRC HT-29 cells with gain-of-function and loss-of-function strategies. In addition, we determined the regulation by STAT3 and RhoA/ROCK1 on the invasion and migration of CRC HT-29 cells. Our study demonstrated a significant upregulation of RhoA and ROCK1 expression and STAT3-Y705 phosphorylation in 32 CRC specimens, compared to the 17 normal CRC tissues. Further study demonstrated there was a coordination between STAT3 and RhoA/Rock signaling in the HT-29 cells. Moreover, STAT3 knockdown or RhoA knockdown significantly repressed the migration and invasion in HT-29 cells and vice versa. STAT3 and RhoA signaling regulate the invasion and migration of CRC cells, implying the orchestrated and oncogenic roles of STAT3 and RhoA/ROCK1 signaling in CRC.

Inter-speaker speech variability assessment using statistical deformable models from 3.0 tesla magnetic resonance images.

PubMed

Vasconcelos, Maria J M; Ventura, Sandra M R; Freitas, Diamantino R S; Tavares, João Manuel R S

2012-03-01

The morphological and dynamic characterisation of the vocal tract during speech production has been gaining greater attention due to the motivation of the latest improvements in magnetic resonance (MR) imaging; namely, with the use of higher magnetic fields, such as 3.0 Tesla. In this work, the automatic study of the vocal tract from 3.0 Tesla MR images was assessed through the application of statistical deformable models. Therefore, the primary goal focused on the analysis of the shape of the vocal tract during the articulation of European Portuguese sounds, followed by the evaluation of the results concerning the automatic segmentation, i.e. identification of the vocal tract in new MR images. In what concerns speech production, this is the first attempt to automatically characterise and reconstruct the vocal tract shape of 3.0 Tesla MR images by using deformable models; particularly, by using active and appearance shape models. The achieved results clearly evidence the adequacy and advantage of the automatic analysis of the 3.0 Tesla MR images of these deformable models in order to extract the vocal tract shape and assess the involved articulatory movements. These achievements are mostly required, for example, for a better knowledge of speech production, mainly of patients suffering from articulatory disorders, and to build enhanced speech synthesizer models.

Rho-ROCK signaling differentially regulates chondrocyte spreading on fibronectin and bone sialoprotein.

PubMed

Gill, Kamal S; Beier, Frank; Goldberg, Harvey A

2008-07-01

The mammalian growth plate is a dynamic structure rich in extracellular matrix (ECM). Interactions of growth plate chondrocytes with ECM proteins regulate cell behavior. In this study, we compared chondrocyte adhesion and spreading dynamics on fibronectin (FN) and bone sialoprotein (BSP). Chondrocyte adhesion and spreading were also compared with fibroblasts to analyze potential cell-type-specific effects. Chondrocyte adhesion to BSP is independent of posttranslational modifications but is dependent on the RGD sequence in BSP. Whereas chondrocytes and fibroblasts adhered at similar levels on FN and BSP, cells displayed more actin-dependent spread on FN despite a 16x molar excess of BSP adsorbed to plastic. To identify intracellular mediators responsible for this difference in spreading, we investigated focal adhesion kinase (FAK)-Src and Rho-Rho kinase (ROCK) signaling. Although activated FAK localized to the vertices of adhered chondrocytes, levels of FAK activation did not correlate with the extent of spreading. Furthermore, Src inhibition reduced chondrocyte spreading on both FN and BSP, suggesting that FAK-Src signaling is not responsible for less cell spreading on BSP. In contrast, inhibition of Rho and ROCK in chondrocytes increased cell spreading on BSP and membrane protrusiveness on FN but did not affect cell adhesion. In fibroblasts, Rho inhibition increased fibroblast spreading on BSP while ROCK inhibition changed membrane protrusiveness of FN and BSP. In summary, we identify a novel role for Rho-ROCK signaling in regulating chondrocyte spreading and demonstrate both cell- and matrix molecule-specific mechanisms controlling cell spreading.

Superoxide constricts rat pulmonary arteries via Rho-kinase-mediated Ca2+ sensitization

PubMed Central

Shaifta, Yasin; Connolly, Michelle; Drndarski, Svetlana; Noah, Anthony; Pourmahram, Ghazaleh E.; Becker, Silke; Aaronson, Philip I.; Ward, Jeremy P.T.

2018-01-01

Reactive oxygen species play a key role in vascular disease, pulmonary hypertension, and hypoxic pulmonary vasoconstriction. We investigated contractile responses, intracellular Ca2+ ([Ca2+]i), Rho-kinase translocation, and phosphorylation of the regulatory subunit of myosin phosphatase (MYPT-1) and of myosin light chain (MLC20) in response to LY83583, a generator of superoxide anion, in small intrapulmonary arteries (IPA) of rat. LY83583 caused concentration-dependent constrictions in IPA and greatly enhanced submaximal PGF2α-mediated preconstriction. In small femoral or mesenteric arteries of rat, LY83583 alone was without effect, but it relaxed a PGF2α-mediated preconstriction. Constrictions in IPA were inhibited by superoxide dismutase and tempol, but not catalase, and were endothelium and guanylate cyclase independent. Constrictions were also inhibited by the Rho-kinase inhibitor Y27632 and the Src-family kinase inhibitor SU6656. LY83583 did not raise [Ca2+]i, but caused a Y27632-sensitive constriction in α-toxin-permeabilized IPA. LY83583 triggered translocation of Rho-kinase from the nucleus to the cytosol in pulmonary artery smooth muscle cells and enhanced phosphorylation of MYPT-1 at Thr-855 and of MLC20 at Ser-19 in IPA. This enhancement was inhibited by superoxide dismutase and abolished by Y27632. Hydrogen peroxide did not activate Rho-kinase. We conclude that in rat small pulmonary artery, superoxide triggers Rho-kinase-mediated Ca2+ sensitization and vasoconstriction independent of hydrogen peroxide. PMID:19103285

Stimulation of Cortical Myosin Phosphorylation by p114RhoGEF Drives Cell Migration and Tumor Cell Invasion

PubMed Central

Zihni, Ceniz; Harris, Andrew R.; Bailly, Maryse; Charras, Guillaume T.; Balda, Maria S.; Matter, Karl

2012-01-01

Actinomyosin activity is an important driver of cell locomotion and has been shown to promote collective cell migration of epithelial sheets as well as single cell migration and tumor cell invasion. However, the molecular mechanisms underlying activation of cortical myosin to stimulate single cell movement, and the relationship between the mechanisms that drive single cell locomotion and those that mediate collective cell migration of epithelial sheets are incompletely understood. Here, we demonstrate that p114RhoGEF, an activator of RhoA that associates with non-muscle myosin IIA, regulates collective cell migration of epithelial sheets and tumor cell invasion. Depletion of p114RhoGEF resulted in specific spatial inhibition of myosin activation at cell-cell contacts in migrating epithelial sheets and the cortex of migrating single cells, but only affected double and not single phosphorylation of myosin light chain. In agreement, overall elasticity and contractility of the cells, processes that rely on persistent and more constant forces, were not affected, suggesting that p114RhoGEF mediates process-specific myosin activation. Locomotion was p114RhoGEF-dependent on Matrigel, which favors more roundish cells and amoeboid-like actinomyosin-driven movement, but not on fibronectin, which stimulates flatter cells and lamellipodia-driven, mesenchymal-like migration. Accordingly, depletion of p114RhoGEF led to reduced RhoA, but increased Rac activity. Invasion of 3D matrices was p114RhoGEF-dependent under conditions that do not require metalloproteinase activity, supporting a role of p114RhoGEF in myosin-dependent, amoeboid-like locomotion. Our data demonstrate that p114RhoGEF drives cortical myosin activation by stimulating myosin light chain double phosphorylation and, thereby, collective cell migration of epithelial sheets and amoeboid-like motility of tumor cells. PMID:23185572

D/sup 0/*. -->. D/sup 0/. gamma. and other radiative decays of vector mesons. [SU-4 groups, decay widths

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

Bohm, A.; Teese, R.B.

1976-01-01

Using SU(4) as a spectrum generating group the radiative decay rates of the charmed vector mesons and of J(psi) are calculated. With the known decay rates of the old mesons GAMMA(..omega.. ..-->.. ..pi gamma..), GAMMA(phi ..-->.. eta ..gamma..), GAMMA(rho ..-->.. ..pi gamma..), GAMMA(K/sup 0/* ..-->.. K/sup 0/..gamma..) as input one obtains GAMMA(K/sup +/* ..-->.. K/sup +/..gamma..) = 2.6 keV, GAMMA(..omega.. ..-->.. eta ..gamma..) = 220 eV, GAMMA(rho ..-->.. eta ..gamma..) = 4.8 keV, GAMMA(psi ..-->.. chi ..gamma..) = 1.6 keV, GAMMA(D/sup 0/* ..-->.. D/sup 0/..gamma..) = 350 eV and GAMMA(D/sup +/* ..-->.. D/sup +/..gamma..) = 22 eV.

Amplitude Analysis of B0 to K^ pi^-pi^0 and Evidence of Direct CP Violation in B to K^* pi decays

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

Lees, J.P.

We analyze the decay B{sup 0} {yields} K{sup +} {pi}{sup -} {pi}{sup 0} with a sample of 454 million B{bar B} events collected by the BABAR detector at the PEP-II asymmetric-energy B factory at SLAC, and extract the complex amplitudes of seven interfering resonances over the Dalitz plot. These results are combined with amplitudes measured in B{sup 0} {yields} K{sup 0}{sub s}{pi}{sup +}{pi}{sup -} decays to construct isospin amplitudes from B{sup 0} {yields} K{sup *}{pi} and B{sup 0} {yields} {rho}K decays. We measure the phase of the isospin amplitude {Phi}{sub 3/2}, useful in constraining the CKM unitarity triangle angle {gamma}more » and evaluate a CP rate asymmetry sum rule sensitive to the presence of new physics operators. We measure direct CP violation in B{sup 0} {yields} K{sup *+}{pi}{sup -} decays at the level of 3 {sigma} when measurements from both B{sup 0} {yields} K{sup +}{pi}{sup -}{pi}{sup 0} and B{sup 0} {yields} K{sup 0}{sub s}{pi}{sup +}{pi}{sup -} decays are combined.« less

Novel molecular insights into RhoA GTPase-induced resistance to aqueous humor outflow through the trabecular meshwork

PubMed Central

Zhang, Min; Maddala, Rupalatha; Rao, Ponugoti Vasantha

2008-01-01

Impaired drainage of aqueous humor through the trabecular meshwork (TM) culminating in increased intraocular pressure is a major risk factor for glaucoma, a leading cause of blindness worldwide. Regulation of aqueous humor drainage through the TM, however, is poorly understood. The role of RhoA GTPase-mediated actomyosin organization, cell adhesive interactions, and gene expression in regulation of aqueous humor outflow was investigated using adenoviral vector-driven expression of constitutively active mutant of RhoA (RhoAV14). Organ-cultured anterior segments from porcine eyes expressing RhoAV14 exhibited significant reduction of aqueous humor outflow. Cultured TM cells expressing RhoAV14 exhibited a pronounced contractile morphology, increased actin stress fibers, and focal adhesions and increased levels of phosphorylated myosin light chain (MLC), collagen IV, fibronectin, and laminin. cDNA microarray analysis of RNA extracted from RhoAV14-expressing human TM cells revealed a significant increase in the expression of genes encoding extracellular matrix (ECM) proteins, cytokines, integrins, cytoskeletal proteins, and signaling proteins. Conversely, various ECM proteins stimulated robust increases in phosphorylation of MLC, paxillin, and focal adhesion kinase and activated Rho GTPase and actin stress fiber formation in TM cells, indicating a potential regulatory feedback interaction between ECM-induced mechanical strain and Rho GTPase-induced isometric tension in TM cells. Collectively, these data demonstrate that sustained activation of Rho GTPase signaling in the aqueous humor outflow pathway increases resistance to aqueous humor outflow through the trabecular pathway by influencing the actomyosin assembly, cell adhesive interactions, and the expression of ECM proteins and cytokines in TM cells. PMID:18799648

First observation of coherent π0 production in neutrino-nucleus interactions with Eν < 2 GeV

NASA Astrophysics Data System (ADS)

Aguilar-Arevalo, A. A.; Anderson, C. E.; Bazarko, A. O.; Brice, S. J.; Brown, B. C.; Bugel, L.; Cao, J.; Coney, L.; Conrad, J. M.; Cox, D. C.; Curioni, A.; Djurcic, Z.; Finley, D. A.; Fleming, B. T.; Ford, R.; Garcia, F. G.; Garvey, G. T.; Green, C.; Green, J. A.; Hart, T. L.; Hawker, E.; Imlay, R.; Johnson, R. A.; Karagiori, G.; Kasper, P.; Katori, T.; Kobilarcik, T.; Kourbanis, I.; Koutsoliotas, S.; Laird, E. M.; Linden, S. K.; Link, J. M.; Liu, Y.; Liu, Y.; Louis, W. C.; Mahn, K. B. M.; Marsh, W.; Martin, P. S.; McGregor, G.; Metcalf, W.; Meyers, P. D.; Mills, F.; Mills, G. B.; Monroe, J.; Moore, C. D.; Nelson, R. H.; Nguyen, V. T.; Nienaber, P.; Nowak, J. A.; Ouedraogo, S.; Patterson, R. B.; Perevalov, D.; Polly, C. C.; Prebys, E.; Raaf, J. L.; Ray, H.; Roe, B. P.; Russell, A. D.; Sandberg, V.; Schirato, R.; Schmitz, D.; Shaevitz, M. H.; Shoemaker, F. C.; Smith, D.; Soderberg, M.; Sorel, M.; Spentzouris, P.; Stancu, I.; Stefanski, R. J.; Sung, M.; Tanaka, H. A.; Tayloe, R.; Tzanov, M.; Van de Water, R.; Wascko, M. O.; White, D. H.; Wilking, M. J.; Yang, H. J.; Zeller, G. P.; Zimmerman, E. D.; MiniBooNE Collaboration

2008-06-01

The MiniBooNE experiment at Fermilab has amassed the largest sample to date of π0s produced in neutral current (NC) neutrino-nucleus interactions at low energy. This Letter reports a measurement of the momentum distribution of π0s produced in mineral oil (CH2) and the first observation of coherent π0 production below 2 GeV. In the forward direction, the yield of events observed above the expectation for resonant production is attributed primarily to coherent production off carbon, but may also include a small contribution from diffractive production on hydrogen. Integrated over the MiniBooNE neutrino flux, the sum of the NC coherent and diffractive modes is found to be (19.5 ± 1.1 (stat) ± 2.5 (sys)) % of all exclusive NC π0 production at MiniBooNE. These measurements are of immediate utility because they quantify an important background to MiniBooNE's search for νμ →νe oscillations.

Au/Zn Contacts to rho-InP: Electrical and Metallurgical Characteristics and the Relationship Between Them

NASA Technical Reports Server (NTRS)

Weizer, Victor G.; Fatemi, Navid S.; Korenyi-Both, Andras L.

1994-01-01

The metallurgical and electrical behavior of Au/Zn contacting metallization on p-type InP was investigated as a function of the Zn content in the metallization. It was found that ohmic behavior can be achieved with Zn concentrations as small as 0.05 atomic percent Zn. For Zn concentrations between 0.1 and 36 at. percent, the contact resistivity rho(sub c) was found to be independent of the Zn content. For low Zn concentrations the realization of ohmic behavior was found to require the growth of the compound Au2P3 at the metal-InP interface. The magnitude of rho(sub c) is shown to be very sensitive to the growth rate of the interfacial Au2P3 layer. The possibility of exploiting this sensitivity to provide low resistance contacts while avoiding the semiconductor structural damage that is normally attendant to contact formation is discussed.

Leiomyoma Cells in 3-Dimensional Cultures Demonstrate an Attenuated Response to Fasudil, a Rho-Kinase Inhibitor, When Compared to 2-Dimensional Cultures

PubMed Central

Malik, Minnie; Britten, Joy; Segars, James

2014-01-01

Uterine leiomyomata are common benign tumors in women of reproductive age and demonstrate an attenuated response to mechanical signaling that involves Rho and integrins. To further characterize the impairment in Rho signaling, we studied the effect of Rho-kinase inhibitor, fasudil, on extracellular matrix production, in 2-dimensional (2D) and 3-dimensional (3D) cultures of leiomyoma and myometrial cells. Leiomyoma 2D cultures demonstrated a rapid decrease in gene transcripts and protein for fibronectin, procollagen 1A, and versican. In 3D cultures, fibronectin and procollagen 1A proteins demonstrated increased levels at lower concentrations of fasudil, followed by a concentration-dependent decrease. Versican protein increased up to 3-fold, whereas fibromodulin demonstrated a significant decrease of 1.92-fold. Myometrial 2D or 3D cultures demonstrated a decrease in all proteins after 72 hours of treatment. The 3D leiomyoma cultures demonstrated a significant increase in active RhoA, followed by a concentration-dependent decrease at higher concentrations. A concentration-dependent increase in phospho-extracellular regulated signal kinase and proapoptotic protein Bax was observed in 3D leiomyoma cultures. Fasudil relaxed the contraction of the 3D collagen gels caused by myometrium and leiomyoma cell growth. These findings indicate that the altered state of Rho signaling in leiomyoma was more clearly observed in 3D cultures. The results also suggest that fasudil may have clinical applicability for treatment of uterine leiomyoma. PMID:25084783

X-linked Inhibitor of Apoptosis Protein (XIAP) Mediates Cancer Cell Motility via Rho GDP Dissociation Inhibitor (RhoGDI)-dependent Regulation of the Cytoskeleton*

PubMed Central

Liu, Jinyi; Zhang, Dongyun; Luo, Wenjing; Yu, Yonghui; Yu, Jianxiu; Li, Jingxia; Zhang, Xinhai; Zhang, Baolin; Chen, Jingyuan; Wu, Xue-Ru; Rosas-Acosta, Germán; Huang, Chuanshu

2011-01-01

X-linked inhibitor of apoptosis protein (XIAP) overexpression has been found to be associated with malignant cancer progression and aggression in individuals with many types of cancers. However, the molecular basis of XIAP in the regulation of cancer cell biological behavior remains largely unknown. In this study, we found that a deficiency of XIAP expression in human cancer cells by either knock-out or knockdown leads to a marked reduction in β-actin polymerization and cytoskeleton formation. Consistently, cell migration and invasion were also decreased in XIAP-deficient cells compared with parental wild-type cells. Subsequent studies demonstrated that the regulation of cell motility by XIAP depends on its interaction with the Rho GDP dissociation inhibitor (RhoGDI) via the XIAP RING domain. Furthermore, XIAP was found to negatively regulate RhoGDI SUMOylation, which might affect its activity in controlling cell motility. Collectively, our studies provide novel insights into the molecular mechanisms by which XIAP regulates cancer invasion and offer a further theoretical basis for setting XIAP as a potential prognostic marker and specific target for treatment of cancers with metastatic properties. PMID:21402697

Flexibility of the zeolite RHO framework. In situ X-ray and neutron powder structural characterization of cation-exchanged BePO and BeAsORHO analogs

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

Nenoff, T.M.; Parise, J.B.; Jones, G.A.

This is an extensive study of the non-aluminosilicate analogs of the zeolite RHO. This molecular sieve is of great interest commercially because of its catalytic properties. In the absence of rigid supporting structural subunits (smaller cages or channels), the aluminosilicate RHO exhibits atypical framework flexibility with large displacivere arrangements. The beryllophosphate and beryalloarsenate analogs are easily synthesized under very mild reaction conditions and therefore maybe of interest for inexpensive and rapid commercial production. However,t hey have decreased thermal stability. In an effort to increase thermal stability and explore framework flexibility, we have synthesized and characterized a series of analogs ofmore » the non-aluminosilicate RHO framework. All materials crystallize in the space group I23, ranging from a = 13.584-(2) A for Li-BePO RHO to a = 14.224(4) A for Ba-RbBeAsO RHO for hydrated phases. The extra framework cations are distributed over the double 8-ring, single 8-ring, and two single 6-ring sites. Partially and fully dehydrated phases were also studied for changes in framework stability. Predictive trends based on the type of cation exchanged into the framework were determined by {sup 9}Be and {sup 31}P MAS NMR. 50 refs., 8 figs., 6 tabs.« less

mTORC2 regulates neutrophil chemotaxis in a cAMP- and RhoA-dependent fashion.

PubMed

Liu, Lunhua; Das, Satarupa; Losert, Wolfgang; Parent, Carole A

2010-12-14

We studied the role of the target of rapamycin complex 2 (mTORC2) during neutrophil chemotaxis, a process that is mediated through the polarization of actin and myosin filament networks. We show that inhibition of mTORC2 activity, achieved via knock down (KD) of Rictor, severely inhibits neutrophil polarization and directed migration induced by chemoattractants, independently of Akt. Rictor KD also abolishes the ability of chemoattractants to induce cAMP production, a process mediated through the activation of the adenylyl cyclase 9 (AC9). Cells with either reduced or higher AC9 levels also exhibit specific and severe tail retraction defects that are mediated through RhoA. We further show that cAMP is excluded from extending pseudopods and remains restricted to the cell body of migrating neutrophils. We propose that the mTORC2-dependent regulation of MyoII occurs through a cAMP/RhoA-signaling axis, independently of actin reorganization during neutrophil chemotaxis. Copyright © 2010 Elsevier Inc. All rights reserved.

Rho kinase inhibition drives megakaryocyte polyploidization and proplatelet formation through MYC and NFE2 downregulation.

PubMed

Avanzi, Mauro P; Goldberg, Francine; Davila, Jennifer; Langhi, Dante; Chiattone, Carlos; Mitchell, William Beau

2014-03-01

The processes of megakaryocyte polyploidization and demarcation membrane system (DMS) formation are crucial for platelet production, but the mechanisms controlling these processes are not fully determined. Inhibition of Rho kinase (ROCK) signalling leads to increased polyploidization in umbilical cord blood-derived megakaryocytes. To extend these findings we determined the effect of ROCK inhibition on development of the DMS and on proplatelet formation. The underlying mechanisms were explored by analysing the effect of ROCK inhibition on the expression of MYC and NFE2, which encode two transcription factors critical for megakaryocyte development. ROCK inhibition promoted DMS formation, and increased proplatelet formation and platelet release. Rho kinase inhibition also downregulated MYC and NFE2 expression in mature megakaryocytes, and this down-regulation correlated with increased proplatelet formation. Our findings suggest a model whereby ROCK inhibition drives polyploidization, DMS growth and proplatelet formation late in megakaryocyte maturation through downregulation of MYC and NFE2 expression. © 2014 John Wiley & Sons Ltd.

RhoE interferes with Rb inactivation and regulates the proliferation and survival of the U87 human glioblastoma cell line

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

Poch, Enric; Minambres, Rebeca; Mocholi, Enric

2007-02-15

Rho GTPases are important regulators of actin cytoskeleton, but they are also involved in cell proliferation, transformation and oncogenesis. One of this proteins, RhoE, inhibits cell proliferation, however the mechanism that regulates this effect remains poorly understood. Therefore, we undertook the present study to determine the role of RhoE in the regulation of cell proliferation. For this purpose we generated an adenovirus system to overexpress RhoE in U87 glioblastoma cells. Our results show that RhoE disrupts actin cytoskeleton organization and inhibits U87 glioblastoma cell proliferation. Importantly, RhoE expressing cells show a reduction in Rb phosphorylation and in cyclin D1 expression.more » Furthermore, RhoE inhibits ERK activation following serum stimulation of quiescent cells. Based in these findings, we propose that RhoE inhibits ERK activation, thereby decreasing cyclin D1 expression and leading to a reduction in Rb inactivation, and that this mechanism is involved in the RhoE-induced cell growth inhibition. Moreover, we also demonstrate that RhoE induces apoptosis in U87 cells and also in colon carcinoma and melanoma cells. These results indicate that RhoE plays an important role in the regulation of cell proliferation and survival, and suggest that this protein may be considered as an oncosupressor since it is capable to induce apoptosis in several tumor cell lines.« less

ISR effects for resonant Higgs production at future lepton colliders

DOE PAGES

Greco, Mario; Han, Tao; Liu, Zhen

2016-11-04

We study the effects of the initial state radiation on themore » $s$-channel Higgs boson resonant production at $$\\mu^+\\mu^-$$ and $e^+e^-$ colliders by convoluting with the beam energy spread profile of the collider and the Breit-Wigner resonance profile of the signal. We assess their impact on both the Higgs signal and SM backgrounds for the leading decay channels $$h\\rightarrow b\\bar b,\\ WW^*$$. In conclusion, our study improves the existing analyses of the proposed future resonant Higgs factories and provides further guidance for the accelerator designs with respect to the physical goals.« less

Constitutional rho-kinase regulates atrioventricular nodal conduction and ventricular repolarization of the canine heart.

PubMed

Sugiyama, Atsushi; Takahara, Akira; Yatomi, Yutaka; Satoh, Yoshioki; Nakamura, Yuji; Hashimoto, Keitaro

2003-06-01

Given the limited information, physiological roles of Rho-kinase in the cardiac conduction system and ventricular repolarization process were assessed in comparison with those in the coronary vascular tone. A specific Rho-kinase inhibitor Y-27632 was administered to the nutrient coronary artery of the canine isolated, blood-perfused atrioventricular node preparation under the monitoring of the ventricular monophasic action potentials. Administration of Y-27632 moderately suppressed the atrioventricular nodal conduction, slightly but significantly accelerated the repolarization process, and potently increased the coronary blood flow, whereas it hardly affected the intraventricular conduction. The estimated concentrations of Y-27632 causing the currently observed effects were enough to inhibit Rho-kinase. These results suggest that constitutional Rho-kinase functions to moderately facilitate the atrioventricular nodal conduction, slightly delay ventricular repolarization process, and significantly increase the coronary vascular tone.

Escherichia coli cytotoxic necrotizing factor 1: evidence for induction of actin assembly by constitutive activation of the p21 Rho GTPase.

PubMed Central

Fiorentini, C; Donelli, G; Matarrese, P; Fabbri, A; Paradisi, S; Boquet, P

1995-01-01

Cytotoxic necrotizing factor type 1 (CNF1) induces in HEp-2 cells an increase in F-actin structures, which was detectable by fluorescence-activated cell sorter analysis 24 h after addition of this factor to the culture medium. Increase in F-actin was correlated with the augmentation of both the cell volume and the total cell actin content. Actin assembly-disassembly is controlled by small GTP-binding proteins of the Rho family, which have been reported recently to be modified by CNF1 treatment. Clostridium difficile toxin B and Clostridium botulinum exoenzyme C3, both known to act on the Rho GTPase, were used as biological tools to study the effect of CNF1 on this protein. CNF1 incubated before, during, or after exposure to the chimeric toxin C3B (which is the product of a genetic fusion between the DNA coding for C3 and the one coding for the B fragment of diphtheria toxin) protected HEp-2 cells from the disruption of F-actin structures caused by inactivation of the Rho GTPase through its ADP-ribosylation. On the other hand, C. difficile toxin B cytopathic effect was not observed upon preincubation of cells with CNF1. Toxins acting through a Rho-independent mechanism, such as cytochalasin D and Clostridium spiroforme iota-like toxin, could not be modified in their cellular activities by CNF1 treatment. All of our results suggest that CNF1 modifies the Rho molecule, thus probably protecting this GTPase from further bacterial toxin modification. PMID:7558302

Escherichia coli cytotoxic necrotizing factor 1: evidence for induction of actin assembly by constitutive activation of the p21 Rho GTPase.

PubMed

Fiorentini, C; Donelli, G; Matarrese, P; Fabbri, A; Paradisi, S; Boquet, P

1995-10-01

Cytotoxic necrotizing factor type 1 (CNF1) induces in HEp-2 cells an increase in F-actin structures, which was detectable by fluorescence-activated cell sorter analysis 24 h after addition of this factor to the culture medium. Increase in F-actin was correlated with the augmentation of both the cell volume and the total cell actin content. Actin assembly-disassembly is controlled by small GTP-binding proteins of the Rho family, which have been reported recently to be modified by CNF1 treatment. Clostridium difficile toxin B and Clostridium botulinum exoenzyme C3, both known to act on the Rho GTPase, were used as biological tools to study the effect of CNF1 on this protein. CNF1 incubated before, during, or after exposure to the chimeric toxin C3B (which is the product of a genetic fusion between the DNA coding for C3 and the one coding for the B fragment of diphtheria toxin) protected HEp-2 cells from the disruption of F-actin structures caused by inactivation of the Rho GTPase through its ADP-ribosylation. On the other hand, C. difficile toxin B cytopathic effect was not observed upon preincubation of cells with CNF1. Toxins acting through a Rho-independent mechanism, such as cytochalasin D and Clostridium spiroforme iota-like toxin, could not be modified in their cellular activities by CNF1 treatment. All of our results suggest that CNF1 modifies the Rho molecule, thus probably protecting this GTPase from further bacterial toxin modification.

Foci of cyclin A2 interact with actin and RhoA in mitosis.

PubMed

Loukil, Abdelhalim; Izard, Fanny; Georgieva, Mariya; Mashayekhan, Shaereh; Blanchard, Jean-Marie; Parmeggiani, Andrea; Peter, Marion

2016-06-09

Cyclin A2 is a key player in the regulation of the cell cycle. Its degradation in mid-mitosis depends primarily on the ubiquitin-proteasome system (UPS), while autophagy also contributes. However, a fraction of cyclin A2 persists beyond metaphase. In this work, we focus on cyclin A2-rich foci detected in mitosis by high resolution imaging and analyse their movements. We demonstrate that cyclin A2 interacts with actin and RhoA during mitosis, and that cyclin A2 depletion induces a dramatic decrease in active RhoA in mitosis. Our data suggest cyclin A2 participation in RhoA activation in late mitosis.

Resonance production in. gamma gamma. collisions

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

Renard, F.M.

1983-04-01

The processes ..gamma gamma.. ..-->.. hadrons can be depicted as follows. One photon creates a q anti q pair which starts to evolve; the other photon can either (A) make its own q anti q pair and the (q anti q q anti q) system continue to evolve or (B) interact with the quarks of the first pair and lead to a modified (q anti q) system in interaction with C = +1 quantum numbers. A review of the recent theoretical activity concerning resonance production and related problems is given under the following headings: hadronic C = +1 spectroscopy (qmore » anti q, qq anti q anti q, q anti q g, gg, ggg bound states and mixing effects); exclusive ..gamma gamma.. processes (generalities, unitarized Born method, VDM and QCD); total cross section (soft and hard contributions); q/sup 2/ dependence of soft processes (soft/hard separation, 1/sup +- +/ resonances); and polarization effects. (WHK)« less

An activating mutant of Rac1 that fails to interact with Rho GDP-dissociation inhibitor stimulates membrane ruffling in mammalian cells.

PubMed Central

Gandhi, Payal N; Gibson, Richard M; Tong, Xiaofeng; Miyoshi, Jun; Takai, Yoshimi; Konieczkowski, Martha; Sedor, John R; Wilson-Delfosse, Amy L

2004-01-01

Rac1, a member of the Rho family of small GTP-binding proteins, is involved in the regulation of the actin cytoskeleton via activation of lamellipodia and membrane ruffle formation. RhoGDI (Rho-family-specific GDP-dissociation inhibitor) forms a complex with Rho proteins in the cytosol of mammalian cells. It not only regulates guanine nucleotide binding to Rho proteins, but may also function as a molecular shuttle to carry Rho proteins from an inactive cytosolic pool to the membrane for activation. These studies tested if RhoGDI is necessary for the translocation of Rac1 from the cytosol to the plasma membrane for the formation of membrane ruffles. We describe a novel mutant of Rac1, R66E (Arg66-->Glu), that fails to bind RhoGDI. This RhoGDI-binding-defective mutation is combined with a Rac1-activating mutation G12V, resulting in a double-mutant [Rac1(G12V/R66E)] that fails to interact with RhoGDI in COS-7 cells, but remains constitutively activated. This double mutant stimulates membrane ruffling to a similar extent as that observed after epidermal growth factor treatment of non-transfected cells. To confirm that Rac1 can signal ruffle formation in the absence of interaction with RhoGDI, Rac1(G12V) was overexpressed in cultured mesangial cells derived from a RhoGDI knockout mouse. Rac1-mediated membrane ruffling was indistinguishable between the RhoGDI(-/-) and RhoGDI(+/+) cell lines. In both the COS-7 and cultured mesangial cells, Rac1(G12V) and Rac1(G12V/R66E) co-localize with membrane ruffles. These findings suggest that interaction with RhoGDI is not essential in the mechanism by which Rac1 translocates to the plasma membrane to stimulate ruffle formation. PMID:14629200

Neuropeptide-stimulated cell migration in prostate cancer cells is mediated by RhoA kinase signaling and inhibited by neutral endopeptidase.

PubMed

Zheng, R; Iwase, A; Shen, R; Goodman, O B; Sugimoto, N; Takuwa, Y; Lerner, D J; Nanus, D M

2006-09-28

The neuropeptides bombesin and endothelin-1 stimulate prostate cancer (PC) cell migration and invasion (J Clin Invest, 2000; 106: 1399-1407). The intracellular signaling pathways that direct this cell movement are not well delineated. The monomeric GTPase RhoA is required for migration in several cell types including neutrophils, monocytes and fibroblasts. We demonstrate that bombesin-stimulated PC cell migration occurs via the heterotrimeric G-protein-coupled receptors (G-protein) G alpha 13 subunit leading to activation of RhoA, and Rho-associated coiled-coil forming protein kinase (ROCK). Using siRNA to suppress expression of the three known G-protein alpha-subunit-associated RhoA guanine nucleotide exchange factors (GEFs), we also show that two of these RhoA GEFs, PDZ-RhoGEF and leukemia-associated RhoGEF (LARG), link bombesin receptors to RhoA in a non-redundant manner in PC cells. We next show that focal adhesion kinase, which activates PDZ-RhoGEF and LARG, is required for bombesin-stimulated RhoA activation. Neutral endopeptidase (NEP) is expressed on normal prostate epithelium whereas loss of NEP expression contributes to PC progression. We also demonstrate that NEP inhibits neuropeptide activation of RhoA. Together, these results establish a contiguous signaling pathway from the bombesin receptor to ROCK in PC cells, and they implicate NEP as a major regulator of neuropeptide-stimulated RhoA in these cells. This work also identifies members of this signaling pathway as potential targets for rational pharmacologic manipulation of neuropeptide-stimulated migration of PC cells.

The Oncogenic Role of RhoGAPs in Basal-Like Breast Cancer

DTIC Science & Technology

2016-04-01

somatic mutations of RhoA in peripheral T cell lymphomas (PTCLs) (16-18) and in diffuse-type gastric carcinomas (19-21). Surprisingly, unlike Rac1...Diffuse-type gastric cancers exhibited mutations in the effector binding domain of RhoA, most commonly Y42C (19-21), which prevents binding to the...Impiombato A, Perez-Garcia A, et al. Recurrent mutations in epigenetic regulators, RHOA and FYN kinase in peripheral T cell lymphomas . Nat Genet 2014;46

Electron cyclotron resonance plasma reactor for production of carbon stripper foil

NASA Astrophysics Data System (ADS)

Faith Romero, Camille; Kanamori, Keita; Kinsho, Michikazu; Yoshimoto, Masahiro; Wada, Motoi

2018-01-01

A graphite antenna for the production of carbon-containing hydrogen plasmas is being developed to prepare impurity-free charge exchange foils for high-energy synchrotrons. Microwave power at 2.45 GHz frequency drives a coaxial structure antenna with a 12-mm-diameter central graphite cylinder and a tapered surrounding cylinder serving as the ground electrode. The antenna was placed in a linear magnetic field to investigate how it performs under an electron cyclotron resonance (ECR) condition. A clear resonance phenomenon was observed in plasma luminosity, microwave power absorption, and microwave power reflection when the induction current used to produce a linear magnetic field was changed. The antenna realized the best microwave coupling to the plasma with the ECR zone formed 5 mm from the end of the center electrode. The antenna realized stable operation for more than 5 h with 100 W input microwave power and with operating hydrogen pressure from 0.5 to 50 Pa.

Rho-ROCK signaling differentially regulates chondrocyte spreading on fibronectin and bone sialoprotein

PubMed Central

Gill, Kamal S.; Beier, Frank; Goldberg, Harvey A.

2008-01-01

The mammalian growth plate is a dynamic structure rich in extracellular matrix (ECM). Interactions of growth plate chondrocytes with ECM proteins regulate cell behavior. In this study, we compared chondrocyte adhesion and spreading dynamics on fibronectin (FN) and bone sialoprotein (BSP). Chondrocyte adhesion and spreading were also compared with fibroblasts to analyze potential cell-type-specific effects. Chondrocyte adhesion to BSP is independent of posttranslational modifications but is dependent on the RGD sequence in BSP. Whereas chondrocytes and fibroblasts adhered at similar levels on FN and BSP, cells displayed more actin-dependent spread on FN despite a 16× molar excess of BSP adsorbed to plastic. To identify intracellular mediators responsible for this difference in spreading, we investigated focal adhesion kinase (FAK)-Src and Rho-Rho kinase (ROCK) signaling. Although activated FAK localized to the vertices of adhered chondrocytes, levels of FAK activation did not correlate with the extent of spreading. Furthermore, Src inhibition reduced chondrocyte spreading on both FN and BSP, suggesting that FAK-Src signaling is not responsible for less cell spreading on BSP. In contrast, inhibition of Rho and ROCK in chondrocytes increased cell spreading on BSP and membrane protrusiveness on FN but did not affect cell adhesion. In fibroblasts, Rho inhibition increased fibroblast spreading on BSP while ROCK inhibition changed membrane protrusiveness of FN and BSP. In summary, we identify a novel role for Rho-ROCK signaling in regulating chondrocyte spreading and demonstrate both cell- and matrix molecule-specific mechanisms controlling cell spreading. PMID:18463228

The C-terminus of the oncoprotein TGAT is necessary for plasma membrane association and efficient RhoA-mediated signaling.

PubMed

van Unen, J; Botman, D; Yin, T; Wu, Y I; Hink, M A; Gadella, T W J; Postma, M; Goedhart, J

2018-06-07

Rho guanine exchange factors (RhoGEFs) control cellular processes such as migration, adhesion and proliferation. Alternative splicing of the RhoGEF Trio produces TGAT. The RhoGEF TGAT is an oncoprotein with constitutive RhoGEF activity. We investigated whether the subcellular location of TGAT is critical for its RhoGEF activity. Since plasma membrane associated RhoGEFs are particularly effective at activating RhoA, plasma membrane localization of TGAT was examined. To this end, we developed a highly sensitive image analysis method to quantitatively measure plasma membrane association. The method requires a cytoplasmic marker and a plasma membrane marker, which are co-imaged with the tagged protein of interest. Linear unmixing is performed to determine the plasma membrane and cytoplasmic component in the fluorescence signal of protein of interest. The analysis revealed that wild-type TGAT is partially co-localized with the plasma membrane. Strikingly, cysteine TGAT-mutants lacking one or more putative palmitoylation sites in the C-tail, still showed membrane association. In contrast, a truncated variant, lacking the last 15 amino acids, TGAT Δ15 , lost membrane association. We show that membrane localization of TGAT was responsible for high RhoGEF activity by using a RhoA FRET-sensor and by determining F-actin levels. Mutants of TGAT that still maintained membrane association showed similar activity as wild-type TGAT. In contrast, the activity was abrogated for the cytoplasmic TGAT Δ15 variant. Synthetic recruitment of TGAT Δ15 to membranes confirmed that TGAT effectively activates RhoA at the plasma membrane. Together, these results show that membrane association of TGAT is critical for its activity.

Rho GTPases, their post-translational modifications, disease-associated mutations and pharmacological inhibitors.

PubMed

Olson, Michael F

2018-05-04

The 20 members of the Rho GTPase family are key regulators of a wide-variety of biological activities. In response to activation, they signal via downstream effector proteins to induce dynamic alterations in the organization of the actomyosin cytoskeleton. In this review, post-translational modifications, mechanisms of dysregulation identified in human pathological conditions, and the ways that Rho GTPases might be targeted for chemotherapy will be discussed.

Infralimbic cortex Rho-kinase inhibition causes antidepressant-like activity in rats.

PubMed

Inan, Salim Yalcin; Soner, Burak Cem; Sahin, Ayse Saide

2015-03-03

Depression is one of the most common psychiatric disorders in the world; however, its mechanisms remain unclear. Recently, a new signal-transduction pathway, namely Rho/Rho-kinase signalling, has been suggested to be involved in diverse cellular events in the central nervous system; such as epilepsy, anxiety-related behaviors, regulation of dendritic and axonal morphology, antinociception, subarachnoid haemorrhage, spinal cord injury and amyotrophic lateral sclerosis. However there is no evidence showing the involvement of Rho-kinase pathway in depression. In addition, the infralimbic cortex, rodent equivalent to subgenual cingulate cortex has been shown to be responsible for emotional responses. Thus, in the present study, intracranial guide cannulae were stereotaxically implanted bilaterally into the infralimbic cortex, and the effects of repeated microinjections of a Rho-kinase (ROCK) inhibitor Y-27632 (10 nmol) were investigated in rats. Y-27632 significantly decreased immobility time and increased swimming and climbing behaviors when compared to fluoxetine (10 μg) and saline groups in the forced swim test. In addition, Y-27632 treatment did not affect spontaneous locomotor activity and forelimb use in the open-field and cylinder tests respectively; but it enhanced limb placing accuracy in the ladder rung walking test. Our results suggest that Y-27632 could be a potentially active antidepressant agent. Copyright © 2014 Elsevier Inc. All rights reserved.

Trio’s Rho-specific GEF domain is the missing Gαq effector in C. elegans

PubMed Central

Williams, Stacey L.; Lutz, Susanne; Charlie, Nicole K.; Vettel, Christiane; Ailion, Michael; Coco, Cassandra; Tesmer, John J.G.; Jorgensen, Erik M.; Wieland, Thomas; Miller, Kenneth G.

2007-01-01

The Gαq pathway is essential for animal life and is a central pathway for driving locomotion, egg laying, and growth in Caenorhabditis elegans, where it exerts its effects through EGL-8 (phospholipase Cβ [PLCβ]) and at least one other effector. To find the missing effector, we performed forward genetic screens to suppress the slow growth and hyperactive behaviors of mutants with an overactive Gαq pathway. Four suppressor mutations disrupted the Rho-specific guanine-nucleotide exchange factor (GEF) domain of UNC-73 (Trio). The mutations produce defects in neuronal function, but not neuronal development, that cause sluggish locomotion similar to animals lacking EGL-8 (PLCβ). Strains containing null mutations in both EGL-8 (PLCβ) and UNC-73 (Trio RhoGEF) have strong synthetic phenotypes that phenocopy the arrested growth and near-complete paralysis of Gαq-null mutants. Using cell-based and biochemical assays, we show that activated C. elegans Gαq synergizes with Trio RhoGEF to activate RhoA. Activated Gαq and Trio RhoGEF appear to be part of a signaling complex, because they coimmunoprecipitate when expressed together in cells. Our results show that Trio’s Rho-specific GEF domain is a major Gαq effector that, together with PLCβ, mediates the Gαq signaling that drives the locomotion, egg laying, and growth of the animal. PMID:17942708

Rho protein GTPases and their interactions with NFκB: crossroads of inflammation and matrix biology

PubMed Central

Tong, Louis; Tergaonkar, Vinay

2014-01-01

The RhoGTPases, with RhoA, Cdc42 and Rac being major members, are a group of key ubiquitous proteins present in all eukaryotic organisms that subserve such important functions as cell migration, adhesion and differentiation. The NFκB (nuclear factor κB) is a family of constitutive and inducible transcription factors that through their diverse target genes, play a major role in processes such as cytokine expression, stress regulation, cell division and transformation. Research over the past decade has uncovered new molecular links between the RhoGTPases and the NFκB pathway, with the RhoGTPases playing a positive or negative regulatory role on NFκB activation depending on the context. The RhoA–NFκB interaction has been shown to be important in cytokine-activated NFκB processes, such as those induced by TNFα (tumour necrosis factor α). On the other hand, Rac is important for activating the NFκB response downstream of integrin activation, such as after phagocytosis. Specific residues of Rac1 are important for triggering NFκB activation, and mutations do obliterate this response. Other upstream triggers of the RhoGTPase–NFκB interactions include the suppressive p120 catenin, with implications for skin inflammation. The networks described here are not only important areas for further research, but are also significant for discovery of targets for translational medicine. PMID:24877606

Inclusive production of the Δ(1232) resonance in muon-proton scattering at 280 GEV/c

NASA Astrophysics Data System (ADS)

Arneodo, M.; Arvidson, A.; Aubert, J. J.; Badelek, B.; Beaufays, J.; Bee, C. P.; Benchouk, C.; Berghoff, G.; Bird, I.; Blum, D.; Böhm, E.; De Bouard, X.; Brasse, F. W.; Braun, H.; Broll, C.; Brown, S.; Brück, H.; Calen, H.; Chima, J. S.; Ciborowski, J.; Clifft, R.; Coignet, G.; Combley, F.; Coughlan, J.; D'Agostini, G.; Dahlgren, S.; Dengler, F.; Derado, I.; Dreyer, T.; Drees, J.; Düren, M.; Eckardt, V.; Edwards, A.; Ernst, T.; Eszes, G.; Favier, J.; Ferrero, M. I.; Figiel, J.; Flauger, W.; Foster, J.; Gabathuler, E.; Gajewski, J.; Gamet, R.; Gayler, J.; Geddes, N.; Giubellino, P.; Graftström, P.; Grard, F.; Haas, J.; Hagberg, E.; Hasert, F. J.; Hayman, P.; Heusse, P.; Hoppe, C.; Jaffré, M.; Jacholkowska, A.; Janata, F.; Jancso, G.; Johnson, A. S.; Kabuss, E. M.; Kellner, G.; Korbel, V.; Krüger, J.; Kullander, S.; Landgraf, U.; Lanske, D.; Loken, J.; Long, K.; Maire, M.; Malecki, P.; Manz, A.; Maselli, S.; Mohr, W.; Montanet, F.; Montgomery, H. E.; Nagy, E.; Nassalski, J.; Norton, P. R.; Oakham, F. G.; Osborne, A. M.; Pascaud, C.; Pawlik, B.; Payre, P.; Peroni, C.; Pessard, H.; Pettingale, J.; Pietrzyk, B.; Pönsgen, B.; Pötsch, M.; Renton, P.; Ribarics, P.; Rith, K.; Rondio, E.; Scheer, M.; Schlagböhmer, A.; Schiemann, H.; Schmitz, N.; Schneegans, M.; Scholz, M.; Schröder, T.; Schouten, M.; Schultze, K.; Sloan, T.; Stier, H. E.; Studt, M.; Taylor, G. N.; Thénard, J. M.; Thompson, J. C.; De La Torre, A.; Toth, J.; Urban, L.; Urban, L.; Wallucks, W.; Whalley, M.; Wheeler, S.; Williams, W. S. C.; Wimpenny, S. J.; Windmolders, R.; Wolf, G.; European Muon Collaboration

1986-01-01

Inclusive production of the Δ (1232) resonance has been measured in 280 GeV/ c muon-proton interactions. The production of the Δ++ as a function of the variables χBJ, W, Q2, χF and pT2 is investigated. The average Δ++ multiplicity is found to be smaller, by a factor of 6.2 ± 1.2, than the average multiplicity of protons. An upper limit for Δ0 production is obtained. The net hadronic charge distribution for events with a Δ++ is presented. The results are compared to the predictions of the Lund and Fire string models.

Immunocytochemical evidence for PDBu-induced activation of RhoA/ROCK in human internal anal sphincter smooth muscle cells

PubMed Central

Singh, Jagmohan; Maxwell, Pinckney J.

2011-01-01

Studies were performed to determine the unknown status of PKC and RhoA/ROCK in the phorbol 12,13-dibutyrate (PDBu)-stimulated state in the human internal anal sphincter (IAS) smooth muscle cells (SMCs). We determined the effects of PDBu (10−7 M), the PKC activator, on PKCα and RhoA and ROCK II translocation in the human IAS SMCs. We used immunocytochemistry and fluorescence microcopy in the basal state, following PDBu, and before and after PKC inhibitor calphostin C (10−6 M), cell-permeable RhoA inhibitor C3 exoenzyme (2.5 μg/ml), and ROCK inhibitor Y 27632 (10−6 M). We also determined changes in the SMC lengths via computerized digital micrometry. In the basal state PKCα was distributed almost uniformly throughout the cell, whereas RhoA and ROCK II were located in the higher intensities toward the periphery. PDBu caused significant translocation of PKCα, RhoA, and ROCK II. PDBu-induced translocation of PKCα was attenuated by calphostin C and not by C3 exoenzyme and Y 27632. However, PDBu-induced translocation of RhoA was blocked by C3 exoenzyme, and that of ROCK II was attenuated by both C3 exoenzyme and Y 27632. Contraction of the human IAS SMCs caused by PDBu in parallel with RhoA/ROCK II translocation was attenuated by C3 exoenzyme and Y 27632 but not by calphostin C. In human IAS SMCs RhoA/ROCK compared with PKC are constitutively active, and contractility by PDBu is associated with RhoA/ROCK activation rather than PKC. The relative contribution of RhoA/ROCK vs. PKC in the pathophysiology and potential therapy for the IAS dysfunction remains to be determined. PMID:21566015

Magnetic resonance angiography of fetal vasculature at 3.0 T.

PubMed

Neelavalli, Jaladhar; Krishnamurthy, Uday; Jella, Pavan K; Mody, Swati S; Yadav, Brijesh K; Hendershot, Kelly; Hernandez-Andrade, Edgar; Yeo, Lami; Cabrera, Maria D; Haacke, Ewart M; Hassan, Sonia S; Romero, Roberto

2016-12-01

Magnetic resonance angiography has not been used much previously for visualizing fetal vessels in utero for reasons that include a contraindication for the use of exogenous contrast agents, maternal respiratory motion and fetal motion. In this work, we report the feasibility of using an appropriately modified clinical time-of-flight magnetic resonance imaging sequence for non-contrast angiography of human fetal and placental vessels at 3.0 T. Using this 2D angiography technique, it is possible to visualize fetal vascular networks in late pregnancy. • 3D-visualization of fetal vasculature is feasible using non-contrast MRA at 3.0 T. • Visualization of placental vasculature is also possible with this method. • Fetal MRA can serve as a vascular localizer for quantitative MRI studies. • This method can be extended to 1.5 T.

Lysophosphatidic acid-induced RhoA signaling and prolonged macrophage infiltration worsens fibrosis and fatty infiltration following rotator cuff tears.

PubMed

Davies, Michael R; Lee, Lawrence; Feeley, Brian T; Kim, Hubert T; Liu, Xuhui

2017-07-01

Previous studies have suggested that macrophage-mediated chronic inflammation is involved in the development of rotator cuff muscle atrophy and degeneration following massive tendon tears. Increased RhoA signaling has been reported in chronic muscle degeneration, such as muscular dystrophy. However, the role of RhoA signaling in macrophage infiltration and rotator muscle degeneration remains unknown. Using a previously established rat model of massive rotator cuff tears, we found RhoA signaling is upregulated in rotator cuff muscle following a massive tendon-nerve injury. This increase in RhoA expression is greatly potentiated by the administration of a potent RhoA activator, lysophosphatidic acid (LPA), and is accompanied by increased TNFα and TGF-β1 expression in rotator cuff muscle. Boosting RhoA signaling with LPA significantly worsened rotator cuff muscle atrophy, fibrosis, and fatty infiltration, accompanied with massive monocytic infiltration of rotator cuff muscles. Co-staining of RhoA and the tissue macrophage marker CD68 showed that CD68+ tissue macrophages are the dominant cell source of increased RhoA signaling in rotator cuff muscles after tendon tears. Taken together, our findings suggest that LPA-mediated RhoA signaling in injured muscle worsens the outcomes of atrophy, fibrosis, and fatty infiltration by increasing macrophage infiltraion in rotator cuff muscle. Clinically, inhibiting RhoA signaling may represent a future direction for developing new treatments to improve muscle quality following massive rotator cuff tears. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:1539-1547, 2017. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.

Human Mammary Epithelial Cell Transformation by Rho GTPase through a Novel Mechanism

DTIC Science & Technology

2008-08-01

structures, termed the terminal ductal–lobular units (TDLUs), together with interlobular fat and fibrous tissue [16,17]. Most breast cancers arise in the...that benign stages (such as typical and atypical hyperplasia ), noninvasive cancers (such as carcinoma in situ – ductal or lobular), and invasive cancers... inflammatory breast cancer and overexpression of RhoC in immortalized hMECs induces their transformation (35). Impor- tantly, given the linkage of Rho

Low-level laser therapy (LLLT) attenuates RhoA mRNA expression in the rat bronchi smooth muscle exposed to tumor necrosis factor-alpha.

PubMed

de Lima, Flávia Mafra; Bjordal, Jan M; Albertini, Regiane; Santos, Fábio V; Aimbire, Flavio

2010-09-01

Low-level laser therapy (LLLT) has been found to produce anti-inflammatory effects in a variety of disorders. Bronchial smooth muscle (BSM) hyperreactivity is associated with increased Ca+2 sensitivity and increased RhoA mRNA expression. In the current study, we investigated if LLLT could reduce BSM contraction force and RhoA mRNA expression in tumor necrosis factor-alpha (TNF-alpha)-induced BSM hyperreactivity. In the study, 112 male Wistar rats were divided randomly into 16 groups, and BSM was harvested and suspended in TNF-alpha baths for 6 and 24 h, respectively. Irradiation with LLLT was performed with a wavelength of 660 nm for 42 s with a dose of 1.3 J/cm2. This LLLT dose was administered once in the 6-h group and twice in the 24-h group. LLLT significantly decreased contraction force in BSM at 6 h (TNF-alpha + LLLT: 11.65+/-1.10 g/100 mg of tissue) (F=3115) and at 24 h (TNF-alpha+ LLLT: 14.15+/-1.1 g/100 mg of tissue) (F=3245, p<0.05) after TNF-alpha, respectively, when compared to vehicle-bathed groups (control). LLLT also significantly decreased the expression of RhoA mRNA in BSM segments at 6 h (1.22+/-0.20) (F=2820, p<0.05) and 24 h (2.13+/-0.20) (F=3324, p<0.05) when compared to BSM segments incubated with TNF-alpha without LLLT irradiation. We conclude that LLLT administered with this protocol, reduces RhoA mRNA expression and BSM contraction force in TNF-alpha-induced BSM hyperreactivity.

Resonance suppression from color reconnection

NASA Astrophysics Data System (ADS)

Acconcia, R.; Chinellato, D. D.; de Souza, R. Derradi; Takahashi, J.; Torrieri, G.; Markert, C.

2018-02-01

We present studies that show how multi-parton interaction and color reconnection affect the hadro-chemistry in proton-proton (pp) collisions with special focus on the production of resonances using the pythia8 event generator. We find that color reconnection suppresses the relative production of meson resonances such as ρ0 and K* , providing an alternative explanation for the K*/K decrease observed in proton-proton collisions as a function of multiplicity by the ALICE collaboration. Detailed studies of the underlying mechanism causing meson resonance suppression indicate that color reconnection leads to shorter, less energetic strings whose fragmentation is less likely to produce more massive hadrons for a given quark content, therefore reducing ratios such as K*/K and ρ0/π in high-multiplicity pp collisions. In addition, we have also studied the effects of allowing string junctions to form and found that these may also contribute to resonance suppression.

Temperature characteristics of SAW resonators on Sc0.26Al0.74N/polycrystalline diamond heterostructures

NASA Astrophysics Data System (ADS)

Sinusía Lozano, M.; Chen, Z.; Williams, Oliver A.; Iriarte, G. F.

2018-07-01

Surface acoustic wave (SAW) resonators have been fabricated on a 2 μm scandium aluminium nitride (ScAlN) film deposited by means of pulsed-DC reactive magnetron sputtering on a 5.8 μm polycrystalline diamond substrate. Thin film characterization comprised of the assessment of the thin film texture by means of x-ray diffraction (XRD) measurements, reporting highly c-axis oriented ScAlN thin films with a full width at half maximum (FWHM) of the ω-θ scans below 2°. Compositional and piezoelectric analyses of the thin films synthesized with the sputtering parameters used in this work, namely a sputtering power of 700 W and a synthesis pressure of 0.53 Pa, have reported a thin film composition of Sc0.26Al0.74N together with a piezoelectric d33 constant of ‑11 pC/N. Finally, a SAW resonator has been characterized using a vector network analyser (VNA) under various substrate temperature conditions with two iterations. The resulting temperature coefficient of frequency (TCF) values show a highly linear behaviour within two temperature ranges, namely from 20 K to room temperature (300 K) (‑12.5 ppm/K) as well as from 300 K up to 450 K (‑34.6 ppm/K).

Regulation of a Rho-associated kinase expression during the corneal epithelial cell cycle.

PubMed

Anderson, S C; SundarRaj, N

2001-04-01

It has been recognized that an increased expression of the Rho-associated kinase (ROCK-I), a downstream target of Rho (a Ras-related small guanosine triphosphatase [GTPase]), is associated with limbal-to-corneal epithelial transition. The purpose of the present study was to determine whether the expression of ROCK-I is regulated during the cell cycle of corneal epithelial cells. Rabbit corneal epithelial cells in culture were subjected to different culture conditions to enrich them in the G0, G1, and S phases of the cell cycle. Indirect immunofluorescence staining and western blot techniques were used for analyzing the changes in the relative intracellular concentrations of ROCK-I. Northern blot analysis of the isolated cellular RNA was performed to estimate the relative concentrations of ROCK-I mRNA. Serum deprivation did not cause all the corneal epithelial cells in culture to be arrested in the G0 phase of the cell cycle. However, the cells could be arrested in G0 by treating them with culture medium supplemented with transforming growth factor (TGF)-beta1. The relative concentration of ROCK-I in the G0-arrested cells was higher than in the corresponding control untreated cultures. G0-arrested cells were induced to enter G1, followed by the S phase of the cell cycle, by refeeding them with the medium devoid of TGF-beta1. The total intracellular concentration of ROCK-I significantly decreased during the G1 phase of the cell cycle and increased again during the S phase. The decrease in intracellular ROCK-I during the G1 phase was confirmed by arresting the cells in G1 with isoleucine deprivation and thymidine-mimosine treatments. ROCK-I mRNA levels were also found to be decreased during the G1 phase of the cell cycle. The levels of ROCK-I in the corneal epithelial cells were significantly lower in the G1 phase than those in the S and G0 phases of the cell cycle. Therefore, a Rho signaling pathway(s) involving ROCK-I may be regulated during the corneal epithelial

Central diffractive resonance production at the LHC

NASA Astrophysics Data System (ADS)

Fiore, Roberto; Jenkovszky, Laszlo; Schicker, Rainer

2016-07-01

Central production of resonances resulting from the scattering of Pomerons in the central rapidity region of proton-proton scattering is studied. Estimates for relevant cross sections are presented. L.J. gratefully acknowledges an EMMI visiting Professorship at the University of Heidelberg for completion of this work. He is grateful to the organizers of this meeting for their hospitality and support. His work was supported also by DOMUS, Hungarian Academy of Sciences

Structure of Shigella IpgB2 in Complex with Human RhoA

PubMed Central

Klink, Björn U.; Barden, Stephan; Heidler, Thomas V.; Borchers, Christina; Ladwein, Markus; Stradal, Theresia E. B.; Rottner, Klemens; Heinz, Dirk W.

2010-01-01

A common theme in bacterial pathogenesis is the manipulation of eukaryotic cells by targeting the cytoskeleton. This is in most cases achieved either by modifying actin, or indirectly via activation of key regulators controlling actin dynamics such as Rho-GTPases. A novel group of bacterial virulence factors termed the WXXXE family has emerged as guanine nucleotide exchange factors (GEFs) for these GTPases. The precise mechanism of nucleotide exchange, however, has remained unclear. Here we report the structure of the WXXXE-protein IpgB2 from Shigella flexneri and its complex with human RhoA. We unambiguously identify IpgB2 as a bacterial RhoA-GEF and dissect the molecular mechanism of GDP release, an essential prerequisite for GTP binding. Our observations uncover that IpgB2 induces conformational changes on RhoA mimicking DbI- but not DOCK family GEFs. We also show that dissociation of the GDP·Mg2+ complex is preceded by the displacement of the metal ion to the α-phosphate of the nucleotide, diminishing its affinity to the GTPase. These data refine our understanding of the mode of action not only of WXXXE GEFs but also of mammalian GEFs of the DH/PH family. PMID:20363740

A molecular mechanism of P-loop pliability of Rho-kinase investigated by molecular dynamic simulation

NASA Astrophysics Data System (ADS)

Gohda, Keigo; Hakoshima, Toshio

2008-11-01

Rho-kinase is a leading player in the regulation of cytoskeletal events involving smooth muscle contraction and neurite growth-cone collapse and retraction, and is a promising drug target in the treatment of both vascular and neurological disorders. Recent crystal structure of Rho-kinase complexed with a small-molecule inhibitor fasudil has revealed structural details of the ATP-binding site, which represents the target site for the inhibitor, and showed that the conserved phenylalanine on the P-loop occupies the pocket, resulting in an increase of protein-ligand contacts. Thus, the P-loop pliability is considered to play an important role in inhibitor binding affinity and specificity. In this study, we carried out a molecular dynamic simulation for Rho-kinase-fasudil complexes with two different P-loop conformations, i.e., the extended and folded conformations, in order to understand the P-loop pliability and dynamics at atomic level. A PKA-fasudil complex was also used for comparison. In the MD simulation, the flip-flop movement of the P-loop conformation starting either from the extended or folded conformation was not able to be observed. However, a significant conformational change in a long loop region covering over the P-loop, and also alteration of ionic interaction-manner of fasudil with acidic residues in the ATP binding site were shown only in the Rho-kinase-fasudil complex with the extended P-loop conformation, while Rho-kinase with the folded P-loop conformation and PKA complexes did not show large fluctuations, suggesting that the Rho-kinase-fasudil complex with the extended P-loop conformation represents a meta-stable state. The information of the P-loop pliability at atomic level obtained in this study could provide valuable clues to designing potent and/or selective inhibitors for Rho-kinase.

Amphetamine activates Rho GTPase signaling to mediate dopamine transporter internalization and acute behavioral effects of amphetamine

PubMed Central

Wheeler, David S.; Underhill, Suzanne M.; Stolz, Donna B.; Murdoch, Geoffrey H.; Thiels, Edda; Romero, Guillermo; Amara, Susan G.

2015-01-01

Acute amphetamine (AMPH) exposure elevates extracellular dopamine through a variety of mechanisms that include inhibition of dopamine reuptake, depletion of vesicular stores, and facilitation of dopamine efflux across the plasma membrane. Recent work has shown that the DAT substrate AMPH, unlike cocaine and other nontransported blockers, can also stimulate endocytosis of the plasma membrane dopamine transporter (DAT). Here, we show that when AMPH enters the cytoplasm it rapidly stimulates DAT internalization through a dynamin-dependent, clathrin-independent process. This effect, which can be observed in transfected cells, cultured dopamine neurons, and midbrain slices, is mediated by activation of the small GTPase RhoA. Inhibition of RhoA activity with C3 exotoxin or a dominant-negative RhoA blocks AMPH-induced DAT internalization. These actions depend on AMPH entry into the cell and are blocked by the DAT inhibitor cocaine. AMPH also stimulates cAMP accumulation and PKA-dependent inactivation of RhoA, thus providing a mechanism whereby PKA- and RhoA-dependent signaling pathways can interact to regulate the timing and robustness of AMPH’s effects on DAT internalization. Consistent with this model, the activation of D1/D5 receptors that couple to PKA in dopamine neurons antagonizes RhoA activation, DAT internalization, and hyperlocomotion observed in mice after AMPH treatment. These observations support the existence of an unanticipated intracellular target that mediates the effects of AMPH on RhoA and cAMP signaling and suggest new pathways to target to disrupt AMPH action. PMID:26553986

RhoA influences the nuclear localization of extracellular signal-regulated kinases to modulate p21Waf/Cip1 expression.

PubMed

Zuckerbraun, Brian S; Shapiro, Richard A; Billiar, Timothy R; Tzeng, Edith

2003-08-19

The 42/44-kD mitogen-activated protein kinases (extracellular signal-regulated kinases, ERKs) regulate smooth muscle cell (SMC) cell-cycle progression and can either promote or inhibit proliferation depending on the activation status of the small GTPase RhoA. RhoA is involved in the regulation of the actin cytoskeleton and converges on multiple signaling pathways. However, the mechanism by which RhoA modulates ERK signaling is not well defined. The purpose of this investigation was to examine whether RhoA regulates ERK downstream signaling and cellular proliferation through its effects on the cytoskeleton and the nuclear localization of ERK. Treatment of SMCs with Clostridia botulinum C3 exoenzyme, which inhibits RhoA activation, decreased SMC proliferation to 24+/-7% of that of controls and increased p21Waf1/Cip1 transcription and protein levels. These effects of RhoA were reversed by inhibition of ERK phosphorylation. However, inactivation of RhoA did not alter levels of ERK phosphorylation but did increase nuclear localization of phosphorylated ERK. In addition, immunostaining demonstrated that phosphorylated ERK associated with the actin cytoskeleton, which was disrupted by C3 exoenzyme. Leptomycin B, an inhibitor of Crm1 that results in ERK nuclear accumulation, similarly increased p21Waf1/Cip1. RhoA inhibition increased levels of phosphorylated ERK in the cell nucleus. Inhibition of RhoA or pharmacological inhibition of nuclear export resulted in increased p21Waf1/Cip1 expression and decreased SMC proliferation, effects that were partially dependent on ERK. RhoA regulation of the actin cytoskeleton may determine ERK subcellular localization and its subsequent effects on SMC proliferation.

Role of ω -meson exchange in scaling of the γ p →π0p process from a Regge-type model with resonances

NASA Astrophysics Data System (ADS)

Kong, Kook-Jin; Choi, Tae Keun; Yu, Byung-Geel

2016-08-01

The scaling of photoproduction γ p →π0p is investigated in the Reggeized model with N* and Δ resonances included to describe resonance peaks up to photon energy Eγ=3 GeV . Given the t -channel exchanges ρ (770 ) +ω (780 ) +b1(1235 ) +h1(1170 ) Reggeized for the background contribution, the resonances of the Breit-Wigner form are introduced to agree with cross sections for total, differential, and beam asymmetry in the low energy region. The scaled differential cross sections s7d σ /d t are reproduced to agree with the recent JLab data, revealing the production mechanism of the big bump structure around W ≈2.2 GeV by the deep-dip pattern of the ω exchange that originates from the zeros of the trajectory αω(t ) =0 in the canonical phase, 1/2 (-1 +e-i π αω(t )) .

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

PubMed

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

2018-06-15

Mesenchymal stem cells (MSC) are suggested to be important progenitors of myofibroblasts in fibrosis. To understand the role of Rho GTPase signaling in TGFβ-induced myofibroblast differentiation of MSC, we generated a novel MSC line and its descendants lacking functional Rho GTPases and Rho GTPase signaling components. Unexpectedly, our data revealed that Rho GTPase signaling is required for TGFβ-induced expression of α-smooth muscle actin (αSMA) but not of collagen I α1 ( col1a1 ). Whereas loss of RhoA and Cdc42 reduced αSMA expression, ablation of the Rac1 gene had the opposite effect. Although actin polymerization and MRTFa were crucial for TGFβ-induced αSMA expression, neither Arp2/3-dependent actin polymerization nor cofilin-dependent severing and depolymerization of F-actin were required. Instead, F-actin levels were dependent on cell contraction, and TGFβ-induced actin polymerization correlated with increased cell contraction mediated by RhoA and Cdc42. Finally, we observed impaired collagen I secretion in MSC lacking RhoA or Cdc42. These data give novel molecular insights into the role of Rho GTPases in TGFβ signaling and have implications for our understanding of MSC function in fibrosis. © 2018 by The American Society for Biochemistry and Molecular Biology, Inc.

The Role of Ect2 Nuclear RhoGEF Activity in Ovarian Cancer Cell Transformation

PubMed Central

Huff, Lauren P.; DeCristo, Molly J.; Trembath, Dimitri; Kuan, Pei Fen; Yim, Margaret; Liu, Jinsong; Cook, Danielle R.; Miller, C. Ryan; Der, Channing J.

2013-01-01

Ect2, a Rho guanine nucleotide exchange factor (RhoGEF), is atypical among RhoGEFs in its predominantly nuclear localization in interphase cells. One current model suggests that Ect2 mislocalization drives cellular transformation by promoting aberrant activation of cytoplasmic Rho family GTPase substrates. However, in ovarian cancers, where Ect2 is both amplified and overexpressed at the mRNA level, we observed that the protein is highly expressed and predominantly nuclear and that nuclear but not cytoplasmic Ect2 increases with advanced disease. Knockdown of Ect2 in ovarian cancer cell lines impaired their anchorage-independent growth without affecting their growth on plastic. Restoration of Ect2 expression rescued the anchorage-independent growth defect, but not if either the DH catalytic domain or the nuclear localization sequences of Ect2 were mutated. These results suggested a novel mechanism whereby Ect2 could drive transformation in ovarian cancer cells by acting as a RhoGEF specifically within the nucleus. Interestingly, Ect2 had an intrinsically distinct GTPase specificity profile in the nucleus versus the cytoplasm. Nuclear Ect2 bound preferentially to Rac1, while cytoplasmic Ect2 bound to RhoA but not Rac. Consistent with nuclear activation of endogenous Rac, Ect2 overexpression was sufficient to recruit Rac effectors to the nucleus, a process that required a functional Ect2 catalytic domain. Furthermore, expression of active nuclearly targeted Rac1 rescued the defect in transformed growth caused by Ect2 knockdown. Our work suggests a novel mechanism of Ect2-driven transformation, identifies subcellular localization as a regulator of GEF specificity, and implicates activation of nuclear Rac1 in cellular transformation. PMID:24386507

Antenatal/early postnatal hypothyroidism increases the contribution of Rho-kinase to contractile responses of mesenteric and skeletal muscle arteries in adult rats.

PubMed

Gaynullina, Dina K; Sofronova, Svetlana I; Shvetsova, Anastasia A; Selivanova, Ekaterina K; Sharova, Anna P; Martyanov, Andrey A; Tarasova, Olga S

2018-05-23

Maternal thyroid deficiency can increase Rho-kinase procontractile influence in arteries of 2-week-old progeny. Here we hypothesized that augmented role of Rho-kinase persists in arteries from adult progeny of hypothyroid rats. Dams were treated with 6-propyl-2-thiouracil (PTU) in drinking water (0.0007%) during pregnancy and 2 weeks postpartum; control (CON) females received PTU-free water. At the age of 10-12-weeks, serum T 3 /T 4 levels did not differ between PTU and CON male offspring. Cutaneous (saphenous), mesenteric, and skeletal muscle (sural) arteries were studied by wire myography, qPCR, and Western blotting. Saphenous arteries of PTU and CON groups showed similar responses to α 1 -adrenoceptor agonist methoxamine and were equally suppressed by Rho-kinase inhibitor Y27632. Responses of mesenteric arteries also did not differ between PTU and CON, but the effects of Y27632 were more prominent in the PTU group. Sural arteries of PTU rats compared to CON demonstrated augmented responses to methoxamine, increased RhoA mRNA contents and higher levels of MYPT1 phosphorylation at Thr 855 . Intergroup differences in contractile responses and phospho-MYPT1-Thr 855 were eliminated by Y27632. Rho-kinase contribution to contractile responses of mesenteric and especially sural arteries is augmented in adult PTU rats. Therefore, maternal thyroid deficiency may have long-term detrimental consequences for vasculature in adult offspring.

Sustained Cutaneous Vasoconstriction during and Following Cyrotherapy Treatment: Role of Oxidative Stress and Rho Kinase

PubMed Central

Christmas, Kevin M.; Patik, Jordan C.; Khoshnevis, Sepideh; Diller, Kenneth R.; Brothers, R. Matthew

2016-01-01

Cryotherapy is a therapeutic technique using ice or cold water applied to the skin to reduce bleeding, inflammation, pain, and swelling following soft tissue trauma and injury. While beneficial, there are some side effects such as pronounced vasoconstriction and tissue ischemia that are sustained for hours post-treatment. This study tested the hypothesis that this vasoconstriction is mediated by 1) the Rho-kinase pathway and/or 2) elevated oxidative stress. 9 subjects were fitted with a commercially available cryotherapy unit with a water perfused bladder on the lateral portion of the right calf. Participants were instrumented with three microdialysis probes underneath the bladder. One site received lactated ringers (control site), one received the Rho-Kinase inhibitor Fasudil, and one received Ascorbic Acid. Skin temperature (Tskin) and cutaneous vascular conductance (CVC) was measured at each site. Subjects had 1 °C water perfused through the bladder for 30 min, followed by passive rewarming for 90 min. Tskin fell from ~ 34 °C to ~ 18.0 °C during active cooling across all sites and this response was similar for all sites (P>0.05 for all comparisons). During passive rewarming Tskin rose to a similar degree in all sites (P>0.05 relative to the end of cooling). %CVC was reduced during active cooling in all sites; however, the magnitude of this response was blunted in the Fasudil site relative to control (P<0.001 for all comparisons) and min 25 and 30 of cooling in the Ascorbic Acid site (P<0.05). During passive rewarming %CVC at the control and Ascorbic Acid sites did not change such that values were similar to the end of cooling (P>0.05 for each comparison). %CVC at the Fasudil site remained elevated during passive rewarming such that values were higher compared to the control and Ascorbic Acid sites throughout the 90 min of passive rewarming (P<0.001 main effect of Fasudi). These findings indicate that the Rho-kinase pathway contributes to pronounced

Rho GTPases Control Polarity, Protrusion, and Adhesion during Cell Movement

PubMed Central

Nobes, Catherine D.; Hall, Alan

1999-01-01

Cell movement is essential during embryogenesis to establish tissue patterns and to drive morphogenetic pathways and in the adult for tissue repair and to direct cells to sites of infection. Animal cells move by crawling and the driving force is derived primarily from the coordinated assembly and disassembly of actin filaments. The small GTPases, Rho, Rac, and Cdc42, regulate the organization of actin filaments and we have analyzed their contributions to the movement of primary embryo fibroblasts in an in vitro wound healing assay. Rac is essential for the protrusion of lamellipodia and for forward movement. Cdc42 is required to maintain cell polarity, which includes the localization of lamellipodial activity to the leading edge and the reorientation of the Golgi apparatus in the direction of movement. Rho is required to maintain cell adhesion during movement, but stress fibers and focal adhesions are not required. Finally, Ras regulates focal adhesion and stress fiber turnover and this is essential for cell movement. We conclude that the signal transduction pathways controlled by the four small GTPases, Rho, Rac, Cdc42, and Ras, cooperate to promote cell movement. PMID:10087266

Mevalonate Cascade and Small Rho GTPase in Spinal Cord Injury.

PubMed

Eftekharpour, Eftekhar; Nagakannan, Pandian; Iqbal, Mohamed Ariff; Chen, Qi Min

2017-01-01

The mevalonate pathway has been extensively studied for its involvement in cholesterol synthesis. Inhibition of this pathway using statins (3-Hydroxy-3-methylglutaryl-coenzyme A reductase inhibitors; HMGR inhibitors) is the primarily selected method due to its cholesterol-lowering effect, making statins the most commonly used (86-94%) cholesterol-lowering drugs in adults. This pathway has several other by-products that are affected by statins including GTPase molecules (guanine triphosphate-binding kinases), such as Rho/Rho-associated coiled kinase (ROCK) kinases, that are implicated in other diseases, including those of the central nervous system (CNS). These molecules control several aspects of neural cell life including axonal growth, cellular migration, and cell death, and therefore, are of increasing interest in the field of spinal cord injury (SCI). Limited regeneration capacity of nerve fibers in adult CNS has been considered the main obstacle for finding a SCI cure. Over the past two decades, the identity of inhibitory factors for regeneration has been widely investigated. It is well-established that the Rho/ROCK kinase system is specifically activated by the components of damaged spinal cord tissue, including oligodendrocytes and myelin, as well as extracellular matrix. This has led many groups to hypothesize that statin therapy may in fact enhance the current neurorestorative approaches. In this mini-review, a summary of SCI pathophysiology is discussed and the current literature targeting the regeneration obstacles in SCI are reviewed, with special attention to recent publications of the past decade. In addition, we focus on the current literature involving the use of pharmacological and molecular inhibitors of small GTPase molecules for treatment of neurotrauma. Inhibiting these molecules has been shown to increase neuroprotection, enhance axonal regeneration, and facilitate the implementation of cell replacement therapies. Based upon available

Oven controlled N++ [1 0 0] length-extensional mode silicon resonator with frequency stability of 1 ppm over industrial temperature range

NASA Astrophysics Data System (ADS)

You, Weilong; Pei, Binbin; Sun, Ke; Zhang, Lei; Yang, Heng; Li, Xinxin

2017-10-01

This paper presents an oven controlled N++ [1 0 0] length-extensional mode silicon resonator, with a lookup-table based control algorithm. The temperature coefficient of resonant frequency (TCF) of the N++ doped resonator is nonlinear, and there is a turnover temperature point at which the TCF is equal to zero. The resonator is maintained at the turnover point by Joule heating; this temperature is a little higher than the upper limit of the industrial temperature range. It is demonstrated that the control algorithm based on the thermoresistor on the substrate and the lookup table for heating voltage versus chip temperature is sufficiently accurate to achieve a frequency stability of  ±0.5 ppm over the industrial temperature range. Because only two leads are required for electrical heating and piezoresistive sensing, the power required for heating of this resonator can be potentially lower than that of the oscillators with closed-loop oven control algorithm. It is also shown that the phase noise can be suppressed at the turnover temperature because of the very low value of the TCF, which justifies the usage of the heating voltage as the excitation voltage of the Wheatstone half-bridge.

Somatostatin, acting at receptor subtype 1, inhibits Rho activity, the assembly of actin stress fibers, and cell migration.

PubMed

Buchan, Alison M J; Lin, Chin-Yu; Choi, Jimmy; Barber, Diane L

2002-08-09

Somatostatin regulates multiple biological functions by acting through a family of five G protein-coupled receptors, somatostatin receptors (SSTRs) 1-5. Although all five receptor subtypes inhibit adenylate cyclase activity and decrease intracellular cAMP levels, specific receptor subtypes also couple to additional signaling pathways. In CCL39 fibroblasts expressing either human SSTR1 or SSTR2, we demonstrate that activation of SSTR1 (but not SSTR2) attenuated both thrombin- and integrin-stimulated Rho-GTP complex formation. The reduction in Rho-GTP formation in the presence of somatostatin was associated with decreased translocation of Rho and LIM kinase to the plasma membrane and fewer focal contacts. Activation of Rho resulted in the formation of intracellular actin stress fibers and cell migration. In CCL39-R1 cells, somatostatin treatment prevented actin stress fiber assembly and attenuated thrombin-stimulated cell migration through Transwell membranes to basal levels. To show that native SSTR1 shares the ability to inhibit Rho activation, we demonstrated that somatostatin treatment of human umbilical vein endothelial cells attenuated thrombin-stimulated Rho-GTP accumulation. These data show for the first time that a G protein-coupled receptor, SSTR1, inhibits the activation of Rho, the assembly of focal adhesions and actin stress fibers, and cell migration.

Eukaryotic Translation Initiation Factor 5A (EIF5A) Regulates Pancreatic Cancer Metastasis by Modulating RhoA and Rho-associated Kinase (ROCK) Protein Expression Levels.

PubMed

Fujimura, Ken; Choi, Sunkyu; Wyse, Meghan; Strnadel, Jan; Wright, Tracy; Klemke, Richard

2015-12-11

Pancreatic ductal adenocarcinoma (PDAC) is one of the deadliest cancers with an overall survival rate of less than 5%. The poor patient outcome in PDAC is largely due to the high prevalence of systemic metastasis at the time of diagnosis and lack of effective therapeutics that target disseminated cells. The fact that the underlying mechanisms driving PDAC cell migration and dissemination are poorly understood have hindered drug development and compounded the lack of clinical success in this disease. Recent evidence indicates that mutational activation of K-Ras up-regulates eIF5A, a component of the cellular translational machinery that is critical for PDAC progression. However, the role of eIF5A in PDAC cell migration and metastasis has not been investigated. We report here that pharmacological inhibition or genetic knockdown of eIF5A reduces PDAC cell migration, invasion, and metastasis in vitro and in vivo. Proteomic profiling and bioinformatic analyses revealed that eIF5A controls an integrated network of cytoskeleton-regulatory proteins involved in cell migration. Functional interrogation of this network uncovered a critical RhoA/ROCK signaling node that operates downstream of eIF5A in invasive PDAC cells. Importantly, eIF5A mediates PDAC cell migration and invasion by modulating RhoA/ROCK protein expression levels. Together our findings implicate eIF5A as a cytoskeletal rheostat controlling RhoA/ROCK protein expression during PDAC cell migration and metastasis. Our findings also implicate the eIF5A/RhoA/ROCK module as a potential new therapeutic target to treat metastatic PDAC cells. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

Role of the a0(980), f0(980) resonances in η → 3π from the Khuri-Treiman formalism

NASA Astrophysics Data System (ADS)

Moussallam, B.; Albaladejo, M.

2016-11-01

The chiral expansion of the η → 3π decay amplitude at NLO fails to reproduce the recent high accuracy measurements of the Dalitz plot parameters. We reconsider the idea of employing the chiral expansion in an unphysical region surrounding the Adler zero and then deducing the amplitude in the physical region using the Khuri-Treiman dispersive formalism. We further present an extension of this formalism which takes into account KK¯ inelastic rescattering effects and thus provides a realistic description of the double a0(980), f0(980) resonance effect. We evaluate how the influence of these resonances propagates down to the low-energy decay region and show that it is significant, in particular for the η → 3π0 decay, and improve the agreement of the predicted Dalitz plot parameters with experiment.

Nonsteroidal anti-inflammatory drugs attenuate amyloid-β protein-induced actin cytoskeletal reorganization through Rho signaling modulation.

PubMed

Ferrera, Patricia; Zepeda, Angélica; Arias, Clorinda

2017-10-01

Amyloid-β protein (Aβ) neurotoxicity occurs along with the reorganization of the actin-cytoskeleton through the activation of the Rho GTPase pathway. In addition to the classical mode of action of the non-steroidal anti-inflammatory drugs (NSAIDs), indomethacin, and ibuprofen have Rho-inhibiting effects. In order to evaluate the role of the Rho GTPase pathway on Aβ-induced neuronal death and on neuronal morphological modifications in the actin cytoskeleton, we explored the role of NSAIDS in human-differentiated neuroblastoma cells exposed to Aβ. We found that Aβ induced neurite retraction and promoted the formation of different actin-dependent structures such as stress fibers, filopodia, lamellipodia, and ruffles. In the presence of Aβ, both NSAIDs prevented neurite collapse and formation of stress fibers without affecting the formation of filopodia and lamellipodia. Similar results were obtained when the downstream effector, Rho kinase inhibitor Y27632, was applied in the presence of Aβ. These results demonstrate the potential benefits of the Rho-inhibiting NSAIDs in reducing Aβ-induced effects on neuronal structural alterations.

Rho differentially regulates the Hippo pathway by modulating the interaction between Amot and Nf2 in the blastocyst.

PubMed

Shi, Xianle; Yin, Zixi; Ling, Bin; Wang, Lingling; Liu, Chang; Ruan, Xianhui; Zhang, Weiyu; Chen, Lingyi

2017-11-01

The Hippo pathway modulates the transcriptional activity of Yap to regulate the differentiation of the inner cell mass (ICM) and the trophectoderm (TE) in blastocysts. Yet how Hippo signaling is differentially regulated in ICM and TE cells is poorly understood. Through an inhibitor/activator screen, we have identified Rho as a negative regulator of Hippo in TE cells, and PKA as a positive regulator of Hippo in ICM cells. We further elucidated a novel mechanism by which Rho suppresses Hippo, distinct from the prevailing view that Rho inhibits Hippo signaling through modulating cytoskeleton remodeling and/or cell polarity. Active Rho prevents the phosphorylation of Amot Ser176, thus stabilizing the interaction between Amot and F-actin, and restricting the binding between Amot and Nf2. Moreover, Rho attenuates the interaction between Amot and Nf2 by binding to the coiled-coil domain of Amot. By blocking the association of Nf2 and Amot, Rho suppresses Hippo in TE cells. © 2017. Published by The Company of Biologists Ltd.

ROCK and RHO Playlist for Preimplantation Development: Streaming to HIPPO Pathway and Apicobasal Polarity in the First Cell Differentiation.

PubMed

Alarcon, Vernadeth B; Marikawa, Yusuke

2018-01-01

In placental mammalian development, the first cell differentiation produces two distinct lineages that emerge according to their position within the embryo: the trophectoderm (TE, placenta precursor) differentiates in the surface, while the inner cell mass (ICM, fetal body precursor) forms inside. Here, we discuss how such position-dependent lineage specifications are regulated by the RHOA subfamily of small GTPases and RHO-associated coiled-coil kinases (ROCK). Recent studies in mouse show that activities of RHO/ROCK are required to promote TE differentiation and to concomitantly suppress ICM formation. RHO/ROCK operate through the HIPPO signaling pathway, whose cell position-specific modulation is central to establishing unique gene expression profiles that confer cell fate. In particular, activities of RHO/ROCK are essential in outside cells to promote nuclear localization of transcriptional co-activators YAP/TAZ, the downstream effectors of HIPPO signaling. Nuclear localization of YAP/TAZ depends on the formation of apicobasal polarity in outside cells, which requires activities of RHO/ROCK. We propose models of how RHO/ROCK regulate lineage specification and lay out challenges for future investigations to deepen our understanding of the roles of RHO/ROCK in preimplantation development. Finally, as RHO/ROCK may be inhibited by certain pharmacological agents, we discuss their potential impact on human preimplantation development in relation to fertility preservation in women.

Measurement of the parity-violating asymmetry in inclusive electroproduction of π - near the Delta 0 resonance

DOE PAGES

Androic, D.; Armstrong, D. S.; Bailey, S. L.; ...

2012-03-20

The parity-violating (PV) asymmetry of inclusive π - production in electron scattering from a liquid deuterium target was measured at backward angles. The measurement was conducted as a part of the G0 experiment, at a beam energy of 360 MeV. The physics process dominating pion production for these kinematics is quasi-free photoproduction off the neutron via the Δ 0 resonance. In the context of heavy-baryon chiral perturbation theory (HBχPT), this asymmetry is related to a low energy constant d Δ - that characterizes the parity-violating γNΔ coupling. Zhu et al. calculated d Δ - in a model benchmarked by themore » large asymmetries seen in hyperon weak radiative decays, and predicted potentially large asymmetries for this process, ranging from A γ - = -5.2 to +5.2 ppm. The measurement performed in this work leads to A γ - = -0.36 ± 1.06 ± 0.37 ± 0.03 ppm (where sources of statistical, systematic and theoretical uncertainties are included), which would disfavor enchancements considered by Zhu et al. proportional to V ud/V us. The measurement is part of a program of inelastic scattering measurements that were conducted by the G0 experiment, seeking to determine the N-Δ axial transition form-factors using PV electron scattering.« less

A Salmonella typhimurium-translocated Glycerophospholipid:Cholesterol Acyltransferase Promotes Virulence by Binding to the RhoA Protein Switch Regions

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

LaRock, Doris L.; Brzovic, Peter S.; Levin, Itay

Salmonella enterica serovar typhimurium translocates a glycerophospholipid: cholesterol acyltransferase (SseJ) into the host cytosol after its entry into mammalian cells. SseJ is recruited to the cytoplasmic face of the host cell phagosome membrane where it is activated upon binding the small GTPase, RhoA. SseJ is regulated similarly to cognate eukaryotic effectors, as only the GTP-bound form of RhoA family members stimulates enzymatic activity. Using NMR and biochemistry, this work demonstrates that SseJ competes effectively with Rhotekin, ROCK, and PKN1 in binding to a similar RhoA surface. The RhoA surface that binds SseJ includes the regulatory switch regions that control activationmore » of mammalian effectors. These data were used to create RhoA mutants with altered SseJ binding and activation. This structure-function analysis supports a model in which SseJ activation occurs predominantly through binding to residues within switch region II. We further defined the nature of the interaction between SseJ and RhoA by constructing SseJ mutants in the RhoA binding surface. These data indicate that SseJ binding to RhoA is required for recruitment of SseJ to the endosomal network and for full Salmonella virulence for inbred susceptible mice, indicating that regulation of SseJ by small GTPases is an important virulence strategy of this bacterial pathogen. The dependence of a bacterial effector on regulation by a mammalian GTPase defines further how intimately host pathogen interactions have coevolved through similar and divergent evolutionary strategies.« less

RPO41-independent maintenance of [rho-] mitochondrial DNA in Saccharomyces cerevisiae.

PubMed

Fangman, W L; Henly, J W; Brewer, B J

1990-01-01

A subset of promoters in the mitochondrial DNA (mtDNA) of the yeast Saccharomyces cerevisiae has been proposed to participate in replication initiation, giving rise to a primer through site-specific cleavage of an RNA transcript. To test whether transcription is essential for mtDNA maintenance, we examined two simple mtDNA deletion ([rho-]) genomes in yeast cells. One genome (HS3324) contains a consensus promoter (ATATAAGTA) for the mitochondrial RNA polymerase encoded by the nuclear gene RPO41, and the other genome (4a) does not. As anticipated, in RPO41 cells transcripts from the HS3324 genome were more abundant than were transcripts from the 4a genome. When the RPO41 gene was disrupted, both [rho-] genomes were efficiently maintained. The level of transcripts from HS3324 mtDNA was decreased greater than 400-fold in cells carrying the RPO41 disrupted gene; however, the low-level transcripts from 4a mtDNA were undiminished. These results indicate that replication of [rho-] genomes can be initiated in the absence of wild-type levels of the RPO41-encoded RNA polymerase.

Rho GTPases and Regulation of Cell Migration and Polarization in Human Corneal Epithelial Cells

PubMed Central

Hou, Aihua; Toh, Li Xian; Gan, Kah Hui; Lee, Khee Jin Ryan; Manser, Edward; Tong, Louis

2013-01-01

Purpose Epithelial cell migration is required for regeneration of tissues and can be defective in a number of ocular surface diseases. This study aimed to determine the expression pattern of Rho family small G-proteins in human corneal epithelial cells to test their requirement in directional cell migration. Methods Rho family small G-protein expression was assessed by reverse transcription-polymerase chain reaction. Dominant-inhibitory constructs encoding Rho proteins or Rho protein targeting small interfering RNA were transfected into human corneal epithelial large T antigen cells, and wound closure rate were evaluated by scratch wounding assay, and a complementary non-traumatic cell migration assay. Immunofluorescence staining was performed to study cell polarization and to assess Cdc42 downstream effector. Results Cdc42, Chp, Rac1, RhoA, TC10 and TCL were expressed in human corneal epithelial cells. Among them, Cdc42 and TCL were found to significantly affect cell migration in monolayer scratch assays. These results were confirmed through the use of validated siRNAs directed to Cdc42 and TCL. Scramble siRNA transfected cells had high percentage of polarized cells than Cdc42 or TCL siRNA transfected cells at the wound edge. We showed that the Cdc42-specific effector p21-activated kinase 4 localized predominantly to cell-cell junctions in cell monolayers, but failed to translocate to the leading edge in Cdc42 siRNA transfected cells after monolayer wounding. Conclusion Rho proteins expressed in cultured human corneal epithelial cells, and Cdc42, TCL facilitate two-dimensional cell migration in-vitro. Although silencing of Cdc42 and TCL did not noticeably affect the appearance of cell adhesions at the leading edge, the slower migration of these cells indicates both GTP-binding proteins play important roles in promoting cell movement of human corneal epithelial cells. PMID:24130842

Search for resonant production of tt decaying to jets in pp collisions at √{s}=1.96 TeV

DOE PAGES

Aaltonen, T.

2011-10-11

This Letter reports a search for non-standard model topquark resonances, Z', decaying to ttMs; →W +bW -b , where both W decay to quarks. We examine the top-antitop quark invariant mass spectrum for the presence of narrow resonant states. The search uses a data sample of p{bar p} collisions at a center of mass energy of 1.96 TeV collected by the CDF II detector at the Fermilab Tevatron, with an integrated luminosity of 2.8 fb -1. No evidence for top-antitop quark resonant production is found. We place upper limits on the production cross section times branching ratio for a specificmore » topcolor assisted technicolor model with width of λ Z' = 0.012 M Z'. Within this model, we exclude Z' boson with masses below 805 GeV/c 2 at the 95% confidence level.« less

Microcrystalline diamond cylindrical resonators with quality-factor up to 0.5 million

NASA Astrophysics Data System (ADS)

Saito, Daisuke; Yang, Chen; Heidari, Amir; Najar, Hadi; Lin, Liwei; Horsley, David A.

2016-02-01

We demonstrate high quality-factor 1.5 mm diameter batch-fabricated microcrystalline diamond cylindrical resonators (CR) with quality-factors limited by thermoelastic damping (TED) and surface loss. Resonators were fabricated 2.6 and 5.3 μm thick in-situ boron-doped microcrystalline diamond films deposited using hot filament chemical vapor deposition. The quality-factor (Q) of as-fabricated CR's was found to increase with the resonator diameter and diamond thickness. Annealing the CRs at 700 °C in a nitrogen atmosphere led to a three-fold increase in Q, a result we attribute to thinning of the diamond layer via reaction with residual O2 in the annealing furnace. Post-anneal Q exceeding 0.5 million (528 000) was measured at the 19 kHz elliptical wineglass modes, producing a ring-down time of 8.9 s. A model for Q versus diamond thickness and resonance frequency is developed including the effects of TED and surface loss. Measured quality factors are shown to agree with the predictions of this model.

Measurements of time-dependent CP violation in B0→ωKS0, f0(980)KS0, KS0π0 and K+K-KS0 decays

NASA Astrophysics Data System (ADS)

Chao, Y.; Chen, K.-F.; Miyake, H.; Tajima, O.; Trabelsi, K.; Abe, K.; Abe, K.; Adachi, I.; Aihara, H.; Anipko, D.; Bakich, A. M.; Barberio, E.; Bitenc, U.; Bizjak, I.; Blyth, S.; Bondar, A.; Bračko, M.; Browder, T. E.; Chang, M.-C.; Chang, P.; Chen, A.; Chen, W. T.; Cheon, B. G.; Chistov, R.; Choi, Y.; Choi, Y. K.; Cole, S.; Dalseno, J.; Danilov, M.; Dash, M.; Dragic, J.; Drutskoy, A.; Eidelman, S.; Fratina, S.; Gabyshev, N.; Golob, B.; Ha, H.; Haba, J.; Hara, K.; Hara, T.; Hastings, N. C.; Hayashii, H.; Hazumi, M.; Heffernan, D.; Higuchi, T.; Hokuue, T.; Hoshi, Y.; Hou, W.-S.; Hsiung, Y. B.; Iijima, T.; Ikado, K.; Inami, K.; Ishikawa, A.; Ishino, H.; Itoh, R.; Iwasaki, M.; Iwasaki, Y.; Kaji, H.; Kang, J. H.; Kapusta, P.; Kawai, H.; Kawasaki, T.; Kim, H. J.; Kim, H. O.; Kim, Y. J.; Kinoshita, K.; Korpar, S.; Križan, P.; Krokovny, P.; Kulasiri, R.; Kumar, R.; Kuo, C. C.; Kuzmin, A.; Kwon, Y.-J.; Lee, M. J.; Lesiak, T.; Limosani, A.; Lin, S.-W.; Liventsev, D.; Matsumoto, T.; McOnie, S.; Miyabayashi, K.; Miyata, H.; Miyazaki, Y.; Mizuk, R.; Mohapatra, D.; Moloney, G. R.; Nakahama, Y.; Nakano, E.; Nakao, M.; Natkaniec, Z.; Nishida, S.; Nitoh, O.; Ogawa, S.; Okuno, S.; Olsen, S. L.; Onuki, Y.; Ozaki, H.; Pakhlov, P.; Pakhlova, G.; Park, C. W.; Pestotnik, R.; Piilonen, L. E.; Sakai, Y.; Satoyama, N.; Schietinger, T.; Schneider, O.; Schwartz, A. J.; Seidl, R.; Senyo, K.; Sevior, M. E.; Shapkin, M.; Shibuya, H.; Singh, J. B.; Somov, A.; Soni, N.; Stanič, S.; Starič, M.; Stoeck, H.; Sumisawa, K.; Sumiyoshi, T.; Suzuki, S.; Takasaki, F.; Tamai, K.; Tanaka, M.; Taylor, G. N.; Teramoto, Y.; Tian, X. C.; Tikhomirov, I.; Tsukamoto, T.; Uehara, S.; Ueno, K.; Unno, Y.; Uno, S.; Ushiroda, Y.; Usov, Y.; Varner, G.; Varvell, K. E.; Villa, S.; Vinokurova, A.; Wang, C. H.; Watanabe, Y.; Won, E.; Yabsley, B. D.; Yamaguchi, A.; Yamashita, Y.; Yamauchi, M.; Yusa, Y.; Zhilich, V.; Zhulanov, V.; Zupanc, A.

2007-11-01

We present measurements of time-dependent CP asymmetries in B0→ωKS0, f0(980)KS0, KS0π0 and K+K-KS0 decays based on a sample of 535×106 BB¯ pairs collected at the Υ(4S) resonance with the Belle detector at the KEKB energy-asymmetric e+e- collider. One neutral B meson is fully reconstructed in one of the specified decay channels, and the flavor of the accompanying B meson is identified from its decay products. CP-violation parameters for each of the decay modes are obtained from the asymmetries in the distributions of the proper-time intervals between the two B decays.

RhoA regulates actin network dynamics during apical surface emergence in multiciliated epithelial cells

PubMed Central

Sedzinski, Jakub; Hannezo, Edouard; Tu, Fan; Biro, Maté

2017-01-01

ABSTRACT Homeostatic replacement of epithelial cells from basal precursors is a multistep process involving progenitor cell specification, radial intercalation and, finally, apical surface emergence. Recent data demonstrate that actin-based pushing under the control of the formin protein Fmn1 drives apical emergence in nascent multiciliated epithelial cells (MCCs), but little else is known about this actin network or the control of Fmn1. Here, we explore the role of the small GTPase RhoA in MCC apical emergence. Disruption of RhoA function reduced the rate of apical surface expansion and decreased the final size of the apical domain. Analysis of cell shapes suggests that RhoA alters the balance of forces exerted on the MCC apical surface. Finally, quantitative time-lapse imaging and fluorescence recovery after photobleaching studies argue that RhoA works in concert with Fmn1 to control assembly of the specialized apical actin network in MCCs. These data provide new molecular insights into epithelial apical surface assembly and could also shed light on mechanisms of apical lumen formation. PMID:28089989

RhoA regulates actin network dynamics during apical surface emergence in multiciliated epithelial cells.

PubMed

Sedzinski, Jakub; Hannezo, Edouard; Tu, Fan; Biro, Maté; Wallingford, John B

2017-01-15

Homeostatic replacement of epithelial cells from basal precursors is a multistep process involving progenitor cell specification, radial intercalation and, finally, apical surface emergence. Recent data demonstrate that actin-based pushing under the control of the formin protein Fmn1 drives apical emergence in nascent multiciliated epithelial cells (MCCs), but little else is known about this actin network or the control of Fmn1. Here, we explore the role of the small GTPase RhoA in MCC apical emergence. Disruption of RhoA function reduced the rate of apical surface expansion and decreased the final size of the apical domain. Analysis of cell shapes suggests that RhoA alters the balance of forces exerted on the MCC apical surface. Finally, quantitative time-lapse imaging and fluorescence recovery after photobleaching studies argue that RhoA works in concert with Fmn1 to control assembly of the specialized apical actin network in MCCs. These data provide new molecular insights into epithelial apical surface assembly and could also shed light on mechanisms of apical lumen formation. © 2017. Published by The Company of Biologists Ltd.

Role of the Rho GTPase Rac in the activation of the phagocyte NADPH oxidase

PubMed Central

Pick, Edgar

2014-01-01

The superoxide-generating NADPH oxidase of phagocytes consists of the membrane-associated cytochrome b558 (a heterodimer of Nox2 and p22phox) and 4 cytosolic components: p47phox, p67phox, p40phox, and the small GTPase, Rac, in complex with RhoGDI. Superoxide is produced by the NADPH-driven reduction of molecular oxygen, via a redox gradient located in Nox2. Electron flow in Nox2 is initiated by interaction with cytosolic components, which translocate to the membrane, p67phox playing the central role. The participation of Rac is expressed in the following sequence: (1) Translocation of the RacGDP-RhoGDI complex to the membrane; (2) Dissociation of RacGDP from RhoGDI; (3) GDP to GTP exchange on Rac, mediated by a guanine nucleotide exchange factor; (4) Binding of RacGTP to p67phox; (5) Induction of a conformational change in p67phox, promoting interaction with Nox2. The particular involvement of Rac in NADPH oxidase assembly serves as a paradigm for signaling by Rho GTPases, in general. PMID:24598074

Training effects on ROS production determined by electron paramagnetic resonance in master swimmers.

PubMed

Mrakic-Sposta, Simona; Gussoni, Maristella; Porcelli, Simone; Pugliese, Lorenzo; Pavei, Gaspare; Bellistri, Giuseppe; Montorsi, Michela; Tacchini, Philippe; Vezzoli, Alessandra

2015-01-01

Acute exercise induces an increase in Reactive Oxygen Species (ROS) production dependent on exercise intensity with highest ROS amount generated by strenuous exercise. However, chronic repetition of exercise, that is, exercise training, may reduce exercise-induced oxidative stress. Aim of this study was to evaluate the effects of 6-weeks high-intensity discontinuous training (HIDT), characterized by repeated variations of intensity and changes of redox potential, on ROS production and antioxidant capacity in sixteen master swimmers. Time course changes of ROS generation were assessed by Electron Paramagnetic Resonance in capillary blood by a microinvasive approach. An incremental arm-ergometer exercise (IE) until exhaustion was carried out at both before (PRE) and after (POST) training (Trg) period. A significant (P < 0.01) increase of ROS production from REST to the END of IE in PRE Trg (2.82 ± 0.66 versus 3.28 ± 0.66 µmol·min(-1)) was observed. HIDT increased peak oxygen consumption (36.1 ± 4.3 versus 40.6 ± 5.7 mL·kg(-1)·min(-1) PRE and POST Trg, resp.) and the antioxidant capacity (+13%) while it significantly decreased the ROS production both at REST (-20%) and after IE (-25%). The observed link between ROS production, adaptive antioxidant defense mechanisms, and peak oxygen consumption provides new insight into the correlation between ROS response pathways and muscle metabolic function.

Local Measurement of the Penetration Depth in the Pnictide Superconductor Ba(Fe_0.95 Co_0.05)_2 As_2

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

Matsushita, Y.

2010-01-11

We use magnetic force microscopy (MFM) to measure the local penetration depth {lambda} in Ba(Fe{sub 0.95}Co{sub 0.05}){sub 2}As{sub 2} single crystals and use scanning SQUID susceptometry to measure its temperature variation down to 0.4 K. We observe that superfluid density {rho}{sub s} over the full temperature range is well described by a clean two-band fully gapped model. We demonstrate that MFM can measure the important and hard-to-determine absolute value of {lambda}, as well as obtain its temperature dependence and spatial homogeneity. We find {rho}{sub s} to be uniform on the submicron scale despite the highly disordered vortex pinning.

New signatures and limits on R-parity violation from resonant squark production

DOE PAGES

Monteux, Angelo

2016-03-31

Here, we discuss resonant squark production at the LHC via baryonic R-parity violating interactions. The cross section easily exceeds pair-production and a new set of signatures can be used to probe squarks, particularly stops. These include dijet resonances, same-sign top quarks and four-jet resonances with large b-jet multiplicities, as well as the possibility of displaced neutralino decays. We use publicly available searches at √s = 8 TeV and first results from collisions at √s = 13 TeV to set upper limits on R-parity violating couplings, with particular focus on simplified models with light stops and neutralinos. The exclusion reach ofmore » these signatures is comparable to R-parity-conserving searches, m t ~ ≃ 500–700 GeV. In addition, we find that O(1) couplings involving the stop can be excluded well into the multi-TeV range, and stress that new searches for single- and pair-produced four-jet resonances will be necessary to exclude sub-TeV stops for a natural SUSY spectrum with light higgsinos.« less

Traumatic noise activates Rho-family GTPases through transient cellular energy depletion

PubMed Central

Chen, Fu-Quan; Zheng, Hong-Wei; Hill, Kayla; Sha, Su-Hua

2012-01-01

Small GTPases mediate transmembrane signaling and regulate the actin cytoskeleton in eukaryotic cells. Here, we characterize the auditory pathology of adult male CBA/J mice exposed to traumatic noise (2–20 kHz; 106 dB; 2 h). Loss of outer hair cells was evident 1 h after noise exposure in the basal region of the cochlea and spread apically with time, leading to permanent threshold shifts of 35, 60, and 65 dB at 8, 16, and 32 kHz. Several biochemical and molecular changes correlated temporally with the loss of cells. Immediately after exposure, the concentration of ATP decreased in cochlear tissue and reached a minimum after 1 h while the immunofluorescent signal for p-AMPKα significantly increased in sensory hair cells at that time. Levels of active Rac1 increased, whereas those of active RhoA decreased significantly 1 h after noise attaining a plateau at 1 to 3 h; the formation of a RhoA-p140mDia complex was consistent with an activation of Rho GTPase pathways. Also at 1 to 3 h after exposure, the caspase-independent cell death marker, endonuclease G, translocated to the nuclei of outer hair cells. Finally, experiments with the inner ear HEI-OC1 cell line demonstrated that the energy-depleting agent oligomycin enhanced both Rac1 activity and cell death. The sum of the results suggests that traumatic noise induces transient cellular ATP depletion and activates Rho GTPase pathways, leading to death of outer hair cells in the cochlea. PMID:22956833

Interactions between the bud emergence proteins Bem1p and Bem2p and Rho-type GTPases in yeast.

PubMed

Peterson, J; Zheng, Y; Bender, L; Myers, A; Cerione, R; Bender, A

1994-12-01

The SH3 domain-containing protein Bem1p is needed for normal bud emergence and mating projection formation, two processes that require asymmetric reorganizations of the cortical cytoskeleton in Saccharomyces cerevisiae. To identify proteins that functionally and/or physically interact with Bem1p, we screened for mutations that display synthetic lethality with a mutant allele of the BEM1 gene and for genes whose products display two-hybrid interactions with the Bem1 protein. CDC24, which is required for bud emergence and encodes a GEF (guanine-nucleotide exchange factor) for the essential Rho-type GTPase Cdc42p, was identified during both screens. The COOH-terminal 75 amino acids of Cdc24p, outside of the GEF domain, can interact with a portion of Bem1p that lacks both SH3 domains. Bacterially expressed Cdc24p and Bem1p bind to each other in vitro, indicating that no other yeast proteins are required for this interaction. The most frequently identified gene that arose from the bem1 synthetic-lethal screen was the bud-emergence gene BEM2 (Bender and Pringle. 1991. Mol. Cell Biol. 11:1295-1395), which is allelic with IPL2 (increase in ploidy; Chan and Botstein, 1993. Genetics. 135:677-691). Here we show that Bem2p contains a GAP (GTPase-activating protein) domain for Rho-type GTPases, and that this portion of Bem2p can stimulate in vitro the GTPase activity of Rho1p, a second essential yeast Rho-type GTPase. Cells deleted for BEM2 become large and multinucleate. These and other genetic, two-hybrid, biochemical, and phenotypic data suggest that multiple Rho-type GTPases control the reorganization of the cortical cytoskeleton in yeast and that the functions of these GTPases are tightly coupled. Also, these findings raise the possibility that Bem1p may regulate or be a target of action of one or more of these GTPases.

Interactions between the bud emergence proteins Bem1p and Bem2p and Rho- type GTPases in yeast

PubMed Central

1994-01-01

The SH3 domain-containing protein Bem1p is needed for normal bud emergence and mating projection formation, two processes that require asymmetric reorganizations of the cortical cytoskeleton in Saccharomyces cerevisiae. To identify proteins that functionally and/or physically interact with Bem1p, we screened for mutations that display synthetic lethality with a mutant allele of the BEM1 gene and for genes whose products display two-hybrid interactions with the Bem1 protein. CDC24, which is required for bud emergence and encodes a GEF (guanine- nucleotide exchange factor) for the essential Rho-type GTPase Cdc42p, was identified during both screens. The COOH-terminal 75 amino acids of Cdc24p, outside of the GEF domain, can interact with a portion of Bem1p that lacks both SH3 domains. Bacterially expressed Cdc24p and Bem1p bind to each other in vitro, indicating that no other yeast proteins are required for this interaction. The most frequently identified gene that arose from the bem1 synthetic-lethal screen was the bud-emergence gene BEM2 (Bender and Pringle. 1991. Mol. Cell Biol. 11:1295-1395), which is allelic with IPL2 (increase in ploidy; Chan and Botstein, 1993. Genetics. 135:677-691). Here we show that Bem2p contains a GAP (GTPase-activating protein) domain for Rho-type GTPases, and that this portion of Bem2p can stimulate in vitro the GTPase activity of Rho1p, a second essential yeast Rho-type GTPase. Cells deleted for BEM2 become large and multinucleate. These and other genetic, two-hybrid, biochemical, and phenotypic data suggest that multiple Rho-type GTPases control the reorganization of the cortical cytoskeleton in yeast and that the functions of these GTPases are tightly coupled. Also, these findings raise the possibility that Bem1p may regulate or be a target of action of one or more of these GTPases. PMID:7962098

P120-Catenin Protects Endplate Chondrocytes From Intermittent Cyclic Mechanical Tension Induced Degeneration by Inhibiting the Expression of RhoA/ROCK-1 Signaling Pathway.

PubMed

Xu, Hong-Guang; Ma, Ming-Ming; Zheng, Quan; Shen, Xiang; Wang, Hong; Zhang, Shu-Feng; Xu, Jia-Jia; Wang, Chuan-Dong; Zhang, Xiao-Ling

2016-08-15

The changes of endplate chondrocytes induced by intermittent cyclic mechanical tension (ICMT) were observed by realtime reverse transcription-polymerase chain reaction, immunofluorescence, and Western blot analysis. To investigate the role of RhoA/ROCK-1 signaling pathway and E-cadherin/P120-catenin complex in endplate chondrocytes degeneration induced by ICMT. ICMT can induce the endplate chondrocyte degeneration. However, the relationship between P120-catenin or RhoA/ROCK-1 signaling pathway and endplate chondrocytes degeneration induced by ICMT is not clear. ICMT (strain at 0.5 Hz sinusoidal curve at 8% elongation) was applied to rat endplate chondrocytes for 6 days, 16 hours a day. The cell viability and apoptosis were examined by the LIVE/DEAD assay and flow cytometry. Histological staining was used to examine the lumbar disc tissue morphology and extracellular matrix. To regulate RhoA/ROCK-1 signaling pathway and the expression of E-cadherin and P120-catenin, RhoA/ROCK-1 pathway-specific inhibitors, E-cadherin, and p120-catenin plasmid were applied. Coimmunoprecipitation was employed to examine the interaction between E-cadherin and P120-catenin, P120-catenin, and RhoA. The related gene expression and protein location was examined by realtime reverse transcription-polymerase chain reaction, Western blot, and immunofluorescence. There was no change of viability verified by LIVE/DEAD assay and flow cytometry after ICMT loading. ICMT loading led to RhoA/ROCK-1 signaling activation and the loss of the chondrogenic phenotype of endplate chondrocytes. Inhibition of RhoA/ROCK-1 signaling pathway significantly ameliorated the degeneration induced by ICMT. The expression of P120-catenin and E-cadherin were inhibited by ICMT. ICMT reduced the interaction between P120-catenin and E-cadherin. Furthermore, over-expression of P120-catenin and E-cadherin can suppress the expression of chondrogenic gene, over-expression of P120-catenin can suppress the RhoA/ROCK-1

Role of the N*(1535) in pp{yields}pp{phi} and {pi}{sup -}p{yields}n{phi} reactions

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

Xie Jujun; Graduate University of Chinese Academy of Sciences, Beijing 100049; Zou Bingsong

2008-01-15

The near-threshold {phi}-meson production in proton-proton and {pi}{sup -}p collisions is studied with the assumption that the production mechanism is due to the sub-N{phi}-threshold N*(1535) resonance. The {pi}{sup 0}-,{eta}-, and {rho}{sup 0}-meson exchanges for proton-proton collisions are considered. It is shown that the contribution to the pp{yields}pp{phi} reaction from the t-channel {pi}{sup 0}-meson exchange is dominant. With a significant N*(1535)N{phi} coupling [g{sub N*(1535)N{phi}}{sup 2}/4{pi}=0.13], both pp{yields}pp{phi} and {pi}{sup -}p{yields}n{phi} data are very well reproduced. The significant coupling of the N*(1535) resonance to N{phi} is compatible with previous indications of a large ss component in the quark wave function of themore » N*(1535) resonance and may be the real origin of the significant enhancement of the {phi} production over the naive OZI-rule predictions.« less

Inhibition of AGEs/RAGE/Rho/ROCK pathway suppresses non-specific neuroinflammation by regulating BV2 microglial M1/M2 polarization through the NF-κB pathway.

PubMed

Chen, Jingkao; Sun, Zhaowei; Jin, Minghua; Tu, Yalin; Wang, Shengnan; Yang, Xiaohong; Chen, Qiuhe; Zhang, Xiao; Han, Yifan; Pi, Rongbiao

2017-04-15

The microglia-mediated neuroinflammation plays an important role in the pathogenesis of Alzheimer's disease (AD). Advanced glycation end products (AGEs)/receptor for advanced glycation end products (RAGE) or Rho/Rho kinase (ROCK) are both involved in the development of non-specific inflammation. However, there are few reports about their effects on neuroinflammation. Here, we explored the mechanism of AGEs/RAGE/Rho/ROCK pathway underlying the non-specific inflammation and microglial polarization in BV2 cells. AGEs could activate ROCK pathway in a concentration-dependent manner. ROCK inhibitor fasudil and RAGE-specific blocker FPS-ZM1 significantly inhibited AGEs-mediated activation of BV2 cells and induction of reactive oxygen species (ROS). FPS-ZM1 and fasudil exerted their anti-inflammatory effects by downregulating inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), NLRP3 and nuclear translocation of nuclear factor kappa B (NF-κB) p65. In addition, AGEs induced both M1 (CD16/32, M1 marker) and M2 (CD206, M2 marker) phenotype in BV2 cells. Fasudil and FPS-ZM1 led to a decreased M1 and increased M2 phenotype. Together, these results indicate that the AGEs/RAGE/Rho/ROCK pathway in BV2 cells could intensify the non-specific inflammation of AD, which will provide novel strategies for the development of anti-AD drugs. Copyright © 2017 Elsevier B.V. All rights reserved.

Signature of a highly spin polarized resonance state at Co2MnSi(0 0 1)/Ag(0 0 1) interfaces

NASA Astrophysics Data System (ADS)

Lidig, Christian; Minár, Jan; Braun, Jürgen; Ebert, Hubert; Gloskovskii, Andrei; Kronenberg, Alexander; Kläui, Mathias; Jourdan, Martin

2018-04-01

We investigated interfaces of halfmetallic Co2MnSi(1 0 0) Heusler thin films with Ag(1 0 0), Cr(1 0 0), Cu and Al layers relevant for spin valves by high energy x-ray photoemission spectroscopy (HAXPES). Experiments on Co2MnSi samples with an Ag(1 0 0) interface showed a characteristic spectral shoulder feature close to the Fermi edge, which is strongly diminished or suppressed at Co2MnSi (1 0 0) interfaces with the other metallic layers. This feature is found to be directly related to the Co2MnSi(1 0 0) layer, as reflected by control experiments with reference non-magnetic films, i.e. without the Heusler layer. By comparison with HAXPES calculations, the shoulder feature is identified as originating from an interface state related to a highly spin polarized surface resonance of Co2MnSi (1 0 0).

Transcription termination factor Rho and microbial phenotypic heterogeneity.

PubMed

Bidnenko, Elena; Bidnenko, Vladimir

2018-06-01

Populations of genetically identical microorganisms exhibit high degree of cell-to-cell phenotypic diversity even when grown in uniform environmental conditions. Heterogeneity is a genetically determined trait, which ensures bacterial adaptation and survival in the ever changing environmental conditions. Fluctuations in gene expression (noise) at the level of transcription initiation largely contribute to cell-to-cell variability within population. Not surprisingly, the analyses of the mechanisms driving phenotypic heterogeneity are mainly focused on the activity of promoters and transcriptional factors. Less attention is currently given to a role of intrinsic and factor-dependent transcription terminators. Here, we discuss recent advances in understanding the regulatory role of the multi-functional transcription termination factor Rho, the major inhibitor of pervasive transcription in bacteria and the emerging global regulator of gene expression. We propose that termination activity of Rho might be among the mechanisms by which cells manage the intensity of transcriptional noise, thus affecting population heterogeneity.

Annexin V-induced rat Leydig cell proliferation involves Ect2 via RhoA/ROCK signaling pathway.

PubMed

Jing, Jun; Chen, Li; Fu, Hai-Yan; Fan, Kai; Yao, Qi; Ge, Yi-Feng; Lu, Jin-Chun; Yao, Bing

2015-03-24

This study investigated the effect of annexin V on the proliferation of primary rat Leydig cells and the potential mechanism. Our results showed that annexin V promoted rat Leydig cell proliferation and cell cycle progression in a dose- and time-dependent manner. Increased level of annexin V also enhanced Ect2 protein expression. However, siRNA knockdown of Ect2 attenuated annexin V-induced proliferation of rat Leydig cells. Taken together, these data suggest that increased level of annexin V induced rat Leydig cell proliferation and cell cycle progression via Ect2. Since RhoA activity was increased following Ect2 activation, we further investigated whether Ect2 was involved in annexin V-induced proliferation via the RhoA/ROCK pathway, and the results showed that annexin V increased RhoA activity too, and this effect was abolished by the knockdown of Ect2. Moreover, inhibition of the RhoA/ROCK pathway by a ROCK inhibitor, Y27632, also attenuated annexin V-induced proliferation and cell cycle progression. We thus conclude that Ect2 is involved in annexin V-induced rat Leydig cell proliferation through the RhoA/ROCK pathway.

Small GTPase Tc10 and its homologue RhoT induce N-WASP-mediated long process formation and neurite outgrowth.

PubMed

Abe, Tomoyuki; Kato, Masayoshi; Miki, Hiroaki; Takenawa, Tadaomi; Endo, Takeshi

2003-01-01

Rho family small GTPases regulate multiple cellular functions through reorganization of the actin cytoskeleton. Among them, Cdc42 and Tc10 induce filopodia or peripheral processes in cultured cells. We have identified a member of the family, designated as RhoT, which is closely related to Tc10. Tc10 was highly expressed in muscular tissues and brain and remarkably induced during differentiation of C2 skeletal muscle cells and neuronal differentiation of PC12 and N1E-115 cells. On the other hand, RhoT was predominantly expressed in heart and uterus and induced during neuronal differentiation of N1E-115 cells. Tc10 exogenously expressed in fibroblasts generated actin-filament-containing peripheral processes longer than the Cdc42-formed filopodia, whereas RhoT produced much longer and thicker processes containing actin filaments. Furthermore, both Tc10 and RhoT induced neurite outgrowth in PC12 and N1E-115 cells, but Cdc42 did not do this by itself. Tc10 and RhoT as well as Cdc42 bound to the N-terminal CRIB-motif-containing portion of N-WASP and activated N-WASP to induce Arp2/3-complex-mediated actin polymerization. The formation of peripheral processes and neurites by Tc10 and RhoT was prevented by the coexpression of dominant-negative mutants of N-WASP. Thus, N-WASP is essential for the process formation and neurite outgrowth induced by Tc10 and RhoT. Neuronal differentiation of PC12 and N1E-115 cells induced by dibutyryl cyclic AMP and by serum starvation, respectively, was prevented by dominant-negative Cdc42, Tc10 and RhoT. Taken together, all these Rho family proteins are required for neuronal differentiation, but they exert their functions differentially in process formation and neurite extension. Consequently, N-WASP activated by these small GTPases mediates neuronal differentiation in addition to its recently identified role in glucose uptake.

Rho2 Palmitoylation Is Required for Plasma Membrane Localization and Proper Signaling to the Fission Yeast Cell Integrity Mitogen-Activated Protein Kinase Pathway

PubMed Central

Sánchez-Mir, Laura; Franco, Alejandro; Martín-García, Rebeca; Madrid, Marisa; Vicente-Soler, Jero; Soto, Teresa; Gacto, Mariano; Pérez, Pilar

2014-01-01

The fission yeast small GTPase Rho2 regulates morphogenesis and is an upstream activator of the cell integrity pathway, whose key element, mitogen-activated protein kinase (MAPK) Pmk1, becomes activated by multiple environmental stimuli and controls several cellular functions. Here we demonstrate that farnesylated Rho2 becomes palmitoylated in vivo at cysteine-196 within its carboxyl end and that this modification allows its specific targeting to the plasma membrane. Unlike that of other palmitoylated and prenylated GTPases, the Rho2 control of morphogenesis and Pmk1 activity is strictly dependent upon plasma membrane localization and is not found in other cellular membranes. Indeed, artificial plasma membrane targeting bypassed the Rho2 need for palmitoylation in order to signal. Detailed functional analysis of Rho2 chimeras fused to the carboxyl end from the essential GTPase Rho1 showed that GTPase palmitoylation is partially dependent on the prenylation context and confirmed that Rho2 signaling is independent of Rho GTP dissociation inhibitor (GDI) function. We further demonstrate that Rho2 is an in vivo substrate for DHHC family acyltransferase Erf2 palmitoyltransferase. Remarkably, Rho3, another Erf2 target, negatively regulates Pmk1 activity in a Rho2-independent fashion, thus revealing the existence of cross talk whereby both GTPases antagonistically modulate the activity of this MAPK cascade. PMID:24820419

RhoA regulates Activin B-induced stress fiber formation and migration of bone marrow-derived mesenchymal stromal cell through distinct signaling.

PubMed

Wang, Xueer; Tang, Pei; Guo, Fukun; Zhang, Min; Chen, Yinghua; Yan, Yuan; Tian, Zhihui; Xu, Pengcheng; Zhang, Lei; Zhang, Lu; Zhang, Lin

2017-01-01

In our previous study, Activin B induced actin stress fiber formation and cell migration in Bone marrow-derived mesenchymal stem cells (BMSCs) in vitro. However, the underlying molecular mechanisms are not well studied. RhoA is recognized to play a critical role in the regulation of actomyosin cytoskeletal organization and cell migration. Pull-down assay was performed to investigate the activity of RhoA. The dominant-negative mutants of RhoA (RhoA(N19)) was used to determine whether RhoA has a role in Activin B-induced cytoskeleton organization and cell migration in BMSCs. Cytoskeleton organization was examined by fluorescence Rhodamine-phalloidin staining, and cell migration by transwell and cell scratching assay. Western blot was carried out to investigate downstream signaling cascade of RhoA. Inhibitor and siRNAs were used to detect the role of downstream signaling in stress fiber formation and/or cell migration. RhoA was activated by Activin B in BMSCs. RhoA(N19) blocked Activin B-induced stress fiber formation and cell migration. ROCK inhibitor blocked Activin B-induced stress fiber formation but enhanced BMSCs migration. Activin B induced phosphorylation of LIMK2 and Cofilin, which was abolished by ROCK inhibition. Both of siRNA LIMK2 and siRNA Cofilin inhibited Activin B-induced stress fiber formation. RhoA regulates Activin B-induced stress fiber formation and migration of BMSCs. A RhoA-ROCK-LIMK2-Cofilin signaling node exists and regulates actin stress fiber formation. RhoA regulates Activin B-induced cell migration independent of ROCK. Better understanding of the molecular mechanisms of BMSCs migration will help optimize therapeutic strategy to target BMSCs at injured tissues. Copyright © 2016 Elsevier B.V. All rights reserved.

Rho1- and Pkc1-dependent phosphorylation of the F-BAR protein Syp1 contributes to septin ring assembly.

PubMed

Merlini, Laura; Bolognesi, Alessio; Juanes, Maria Angeles; Vandermoere, Franck; Courtellemont, Thibault; Pascolutti, Roberta; Séveno, Martial; Barral, Yves; Piatti, Simonetta

2015-09-15

In many cell types, septins assemble into filaments and rings at the neck of cellular appendages and/or at the cleavage furrow to help compartmentalize the plasma membrane and support cytokinesis. How septin ring assembly is coordinated with membrane remodeling and controlled by mechanical stress at these sites is unclear. Through a genetic screen, we uncovered an unanticipated link between the conserved Rho1 GTPase and its effector protein kinase C (Pkc1) with septin ring stability in yeast. Both Rho1 and Pkc1 stabilize the septin ring, at least partly through phosphorylation of the membrane-associated F-BAR protein Syp1, which colocalizes asymmetrically with the septin ring at the bud neck. Syp1 is displaced from the bud neck upon Pkc1-dependent phosphorylation at two serines, thereby affecting the rigidity of the new-forming septin ring. We propose that Rho1 and Pkc1 coordinate septin ring assembly with membrane and cell wall remodeling partly by controlling Syp1 residence at the bud neck. © 2015 Merlini et al. This article is distributed by The American Society for Cell Biology under license from the author(s). Two months after publication it is available to the public under an Attribution–Noncommercial–Share Alike 3.0 Unported Creative Commons License (http://creativecommons.org/licenses/by-nc-sa/3.0).

The Differential Cross Section and Λ Recoil Polarization from γδ -> Κ0(ρ)

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

Compton, Nicholas; Thomas Jefferson National Accelerator Facility

2017-04-30

Presented is the analysis of the differential cross section and Λ recoil polarization from the reaction γδ -> Κ0(ρ). This work measured these observables over beam energies from 0.90 GeV to 3.0 GeV. These measurements are the first in this channel to cover such a wide range of energies. The data were taken using the CEBAF Large Acceptance Spectrometer (CLAS) at Jefferson Laboratory (JLAB) along with a tagged photon beam. This analysis was completed by identifying events of interest that decayed into the final state topology of π-π+,π-&rho'(ρ). Through conservation of energy and momentum, the Κ0, Λ and missing massmore » of the spectator proton were reconstructed. Utilizing the same analysis techniques, the observables were measured on two different experiments with good agreement. Photoproduction of strange mesons from the neutron are difficult to measure, consequently there are only a few measurements of this kind. Despite that, these reactions supply essential complementary data to those on the proton. The differential cross sections and the recoil polarization extracted, span the region where new nucleon resonances have been found from studies of the reaction γρ -> Κ+Λ. Comparisons between the Κ+Λ and Κ0Λ cross section demonstrate that possible interference terms near 1900 MeV are less pronounced in the latter. This unexpected result inspired a partial wave analyses (PWA) to be fitted to the data. The fit solution shows that this measurement fostered an improvement on the knowledge of observed resonance parameters, necessary to understanding these excited states. The study of nucleon resonances is a key motivating factor since the resonance masses can be calculated from the theory of the strong nuclear force, called quantum chromodynamics, or QCD.« less

Identification of RhoGAP22 as an Akt-Dependent Regulator of Cell Motility in Response to Insulin▿‡

PubMed Central

Rowland, Alexander F.; Larance, Mark; Hughes, William E.; James, David E.

2011-01-01

Insulin exerts many of its metabolic actions via the canonical phosphatidylinositide 3 kinase (PI3K)/Akt pathway, leading to phosphorylation and 14-3-3 binding of key metabolic targets. We previously identified a GTPase-activating protein (GAP) for Rac1 called RhoGAP22 as an insulin-responsive 14-3-3 binding protein. Insulin increased 14-3-3 binding to RhoGAP22 fourfold, and this effect was PI3K dependent. We identified two insulin-responsive 14-3-3 binding sites (pSer16 and pSer395) within RhoGAP22, and mutagenesis studies revealed a complex interplay between the phosphorylation at these two sites. Mutating Ser16 to alanine blocked 14-3-3 binding to RhoGAP22 in vivo, and phosphorylation at Ser16 was mediated by the kinase Akt. Overexpression of a mutant RhoGAP22 that was unable to bind 14-3-3 reduced cell motility in NIH-3T3 fibroblasts, and this effect was dependent on a functional GAP domain. Mutation of the catalytic arginine of the GAP domain of RhoGAP22 potentiated growth factor-stimulated Rac1 GTP loading. We propose that insulin and possibly growth factors such as platelet-derived growth factor may play a novel role in regulating cell migration and motility via the Akt-dependent phosphorylation of RhoGAP22, leading to modulation of Rac1 activity. PMID:21969604

Cell Cycle-Dependent Rho GTPase Activity Dynamically Regulates Cancer Cell Motility and Invasion In Vivo

PubMed Central

Kagawa, Yoshinori; Matsumoto, Shinji; Kamioka, Yuji; Mimori, Koshi; Naito, Yoko; Ishii, Taeko; Okuzaki, Daisuke; Nishida, Naohiro; Maeda, Sakae; Naito, Atsushi; Kikuta, Junichi; Nishikawa, Keizo; Nishimura, Junichi; Haraguchi, Naotsugu; Takemasa, Ichiro; Mizushima, Tsunekazu; Ikeda, Masataka; Yamamoto, Hirofumi; Sekimoto, Mitsugu; Ishii, Hideshi; Doki, Yuichiro; Matsuda, Michiyuki; Kikuchi, Akira; Mori, Masaki; Ishii, Masaru

2013-01-01

The mechanism behind the spatiotemporal control of cancer cell dynamics and its possible association with cell proliferation has not been well established. By exploiting the intravital imaging technique, we found that cancer cell motility and invasive properties were closely associated with the cell cycle. In vivo inoculation of human colon cancer cells bearing fluorescence ubiquitination-based cell cycle indicator (Fucci) demonstrated an unexpected phenomenon: S/G2/M cells were more motile and invasive than G1 cells. Microarray analyses showed that Arhgap11a, an uncharacterized Rho GTPase-activating protein (RhoGAP), was expressed in a cell-cycle-dependent fashion. Expression of ARHGAP11A in cancer cells suppressed RhoA-dependent mechanisms, such as stress fiber formation and focal adhesion, which made the cells more prone to migrate. We also demonstrated that RhoA suppression by ARHGAP11A induced augmentation of relative Rac1 activity, leading to an increase in the invasive properties. RNAi-based inhibition of Arhgap11a reduced the invasion and in vivo expansion of cancers. Additionally, analysis of human specimens showed the significant up-regulation of Arhgap11a in colon cancers, which was correlated with clinical invasion status. The present study suggests that ARHGAP11A, a cell cycle-dependent RhoGAP, is a critical regulator of cancer cell mobility and is thus a promising therapeutic target in invasive cancers. PMID:24386239

Cell cycle-dependent Rho GTPase activity dynamically regulates cancer cell motility and invasion in vivo.

PubMed

Kagawa, Yoshinori; Matsumoto, Shinji; Kamioka, Yuji; Mimori, Koshi; Naito, Yoko; Ishii, Taeko; Okuzaki, Daisuke; Nishida, Naohiro; Maeda, Sakae; Naito, Atsushi; Kikuta, Junichi; Nishikawa, Keizo; Nishimura, Junichi; Haraguchi, Naotsugu; Takemasa, Ichiro; Mizushima, Tsunekazu; Ikeda, Masataka; Yamamoto, Hirofumi; Sekimoto, Mitsugu; Ishii, Hideshi; Doki, Yuichiro; Matsuda, Michiyuki; Kikuchi, Akira; Mori, Masaki; Ishii, Masaru

2013-01-01

The mechanism behind the spatiotemporal control of cancer cell dynamics and its possible association with cell proliferation has not been well established. By exploiting the intravital imaging technique, we found that cancer cell motility and invasive properties were closely associated with the cell cycle. In vivo inoculation of human colon cancer cells bearing fluorescence ubiquitination-based cell cycle indicator (Fucci) demonstrated an unexpected phenomenon: S/G2/M cells were more motile and invasive than G1 cells. Microarray analyses showed that Arhgap11a, an uncharacterized Rho GTPase-activating protein (RhoGAP), was expressed in a cell-cycle-dependent fashion. Expression of ARHGAP11A in cancer cells suppressed RhoA-dependent mechanisms, such as stress fiber formation and focal adhesion, which made the cells more prone to migrate. We also demonstrated that RhoA suppression by ARHGAP11A induced augmentation of relative Rac1 activity, leading to an increase in the invasive properties. RNAi-based inhibition of Arhgap11a reduced the invasion and in vivo expansion of cancers. Additionally, analysis of human specimens showed the significant up-regulation of Arhgap11a in colon cancers, which was correlated with clinical invasion status. The present study suggests that ARHGAP11A, a cell cycle-dependent RhoGAP, is a critical regulator of cancer cell mobility and is thus a promising therapeutic target in invasive cancers.

Microcrystalline diamond cylindrical resonators with quality-factor up to 0.5 million

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

Saito, Daisuke; Yang, Chen; Lin, Liwei

2016-02-01

We demonstrate high quality-factor 1.5 mm diameter batch-fabricated microcrystalline diamond cylindrical resonators (CR) with quality-factors limited by thermoelastic damping (TED) and surface loss. Resonators were fabricated 2.6 and 5.3 μm thick in-situ boron-doped microcrystalline diamond films deposited using hot filament chemical vapor deposition. The quality-factor (Q) of as-fabricated CR's was found to increase with the resonator diameter and diamond thickness. Annealing the CRs at 700 °C in a nitrogen atmosphere led to a three-fold increase in Q, a result we attribute to thinning of the diamond layer via reaction with residual O{sub 2} in the annealing furnace. Post-anneal Q exceeding 0.5 million (528 000)more » was measured at the 19 kHz elliptical wineglass modes, producing a ring-down time of 8.9 s. A model for Q versus diamond thickness and resonance frequency is developed including the effects of TED and surface loss. Measured quality factors are shown to agree with the predictions of this model.« less

Leukemia-associated Rho guanine nucleotide exchange factor (LARG) plays an agonist specific role in platelet function through RhoA activation

PubMed Central

Zou, Siying; Teixeira, Alexandra M.; Yin, Mingzhu; Xiang, Yaozu; Xavier-Ferruccio, Juliana; Zhang, Ping-xia; Hwa, John; Min, Wang; Krause, Diane S.

2018-01-01

Summary Leukemia-Associated RhoGEF (LARG) is highly expressed in platelets, which are essential for maintaining normal hemostasis. We studied the function of LARG in murine and human megakaryocytes and platelets with Larg knockout, shRNA-mediated knockdown and small molecule-mediated inhibition. We found that LARG is important for human, but not murine, megakaryocyte maturation. Larg KO mice exhibit macrothrombocytopenia, internal bleeding in the ovaries and prolonged bleeding times. KO platelets have impaired aggregation, α-granule release and integrin α2bβ3 activation in response to thrombin and thromboxane, but not to ADP. The same agonist-specific reductions in platelet aggregation occur in human platelets treated with a LARG inhibitor. Larg KO platelets have reduced RhoA activation and myosin light chain phosphorylation, suggesting that Larg plays an agonist-specific role in platelet signal transduction. Using 2 different in vivo assays, Larg KO mice are protected from in vivo thrombus formation. Together, these results establish that LARG regulates human megakaryocyte maturation, and is critical for platelet function in both humans and mice. PMID:27345948

Leukaemia-associated Rho guanine nucleotide exchange factor (LARG) plays an agonist specific role in platelet function through RhoA activation.

PubMed

Zou, Siying; Teixeira, Alexandra M; Yin, Mingzhu; Xiang, Yaozu; Xavier-Ferrucio, Juliana; Zhang, Ping-Xia; Hwa, John; Min, Wang; Krause, Diane S

2016-08-30

Leukemia-Associated RhoGEF (LARG) is highly expressed in platelets, which are essential for maintaining normal haemostasis. We studied the function of LARG in murine and human megakaryocytes and platelets with Larg knockout (KO), shRNA-mediated knockdown and small molecule-mediated inhibition. We found that LARG is important for human, but not murine, megakaryocyte maturation. Larg KO mice exhibit macrothrombocytopenia, internal bleeding in the ovaries and prolonged bleeding times. KO platelets have impaired aggregation, α-granule release and integrin α2bβ3 activation in response to thrombin and thromboxane, but not to ADP. The same agonist-specific reductions in platelet aggregation occur in human platelets treated with a LARG inhibitor. Larg KO platelets have reduced RhoA activation and myosin light chain phosphorylation, suggesting that Larg plays an agonist-specific role in platelet signal transduction. Using two different in vivo assays, Larg KO mice are protected from in vivo thrombus formation. Together, these results establish that LARG regulates human megakaryocyte maturation, and is critical for platelet function in both humans and mice.

HAWC+/SOFIA observations of Rho Oph A: far-infrared polarization spectrum

NASA Astrophysics Data System (ADS)

Santos, Fabio; Dowell, Charles D.; Houde, Martin; Looney, Leslie; Lopez-Rodriguez, Enrique; Novak, Giles; Ward-Thompson, Derek; HAWC+ Science Team

2018-01-01

In this work, we present preliminary results from the HAWC+ far-infrared polarimeter that operates on the SOFIA airborne observatory. The densest portions of the Rho Ophiuchi molecular complex, known as Rho Oph A, have been mapped using HAWC+ bands C (89 microns) and D (155 microns). Rho Oph A is a well known nearby star forming region. At the target's distance of approximately 130 pc, our observations provide excellent spatial resolution (~5 mpc in band C).The magnetic field map suggests a compressed and distorted field morphology around Oph S1, a massive B3 star that is the main heat source of Rho Oph A. We compute the ratio p(D)/p(C), where p(C) and p(D) are the polarization degree maps at bands C and D, respectively. This ratio estimates the slope of the polarization spectrum in the far-infrared. Although the slope is predicted to be positive by dust grain models, previous observations of other molecular clouds have revealed that negative slopes are common. In Rho Oph A, we find that there is a smooth gradient of p(D)/p(C) across the mapped field. The change in p(D)/p(C) is well correlated with the integrated NH3 (1,1) emission. A positive slope dominates the lower density and well illuminated portions of the cloud, whereas a transition to a negative slope is observed at the denser and less evenly illuminated cloud core.We interpret the positive to negative slope transition as being consistent with the radiative torques (RATs) grain alignment theory. For the sight lines of higher column density, polarized emission from the warmer outer cloud layers is added to emission from the colder inner well-shielded layers lying along the same line-of-sight. Given that the outer layers receive more radiation from Oph S1, their grain alignment efficiency is expected to be higher according to RATs. The combination of warmer, well aligned grains with cooler, poorly aligned grains is what causes the negative slope. This effect is not present in the sight lines of lower column

Wash functions downstream of Rho1 GTPase in a subset of Drosophila immune cell developmental migrations

PubMed Central

Verboon, Jeffrey M.; Rahe, Travis K.; Rodriguez-Mesa, Evelyn; Parkhurst, Susan M.

2015-01-01

Drosophila immune cells, the hemocytes, undergo four stereotypical developmental migrations to populate the embryo, where they provide immune reconnoitering, as well as a number of non–immune-related functions necessary for proper embryogenesis. Here, we describe a role for Rho1 in one of these developmental migrations in which posteriorly located hemocytes migrate toward the head. This migration requires the interaction of Rho1 with its downstream effector Wash, a Wiskott–Aldrich syndrome family protein. Both Wash knockdown and a Rho1 transgene harboring a mutation that prevents Wash binding exhibit the same developmental migratory defect as Rho1 knockdown. Wash activates the Arp2/3 complex, whose activity is needed for this migration, whereas members of the WASH regulatory complex (SWIP, Strumpellin, and CCDC53) are not. Our results suggest a WASH complex–independent signaling pathway to regulate the cytoskeleton during a subset of hemocyte developmental migrations. PMID:25739458

RhoA Inhibitor Treatment At Acute Phase of Spinal Cord Injury May Induce Neurite Outgrowth and Synaptogenesis.

PubMed

Devaux, Stephanie; Cizkova, Dasa; Mallah, Khalil; Karnoub, Melodie Anne; Laouby, Zahra; Kobeissy, Firas; Blasko, Juraj; Nataf, Serge; Pays, Laurent; Mériaux, Céline; Fournier, Isabelle; Salzet, Michel

2017-08-01

The therapeutic use of RhoA inhibitors (RhoAi) has been experimentally tested in spinal cord injury (SCI). In order to decipher the underlying molecular mechanisms involved in such a process, an in vitro neuroproteomic-systems biology platform was developed in which the pan-proteomic profile of the dorsal root ganglia (DRG) cell line ND7/23 DRG was assessed in a large array of culture conditions using RhoAi and/or conditioned media obtained from SCI ex vivo derived spinal cord slices. A fine mapping of the spatio-temporal molecular events of the RhoAi treatment in SCI was performed. The data obtained allow a better understanding of regeneration/degeneration induced above and below the lesion site. Results notably showed a time-dependent alteration of the transcription factors profile along with the synthesis of growth cone-related factors (receptors, ligands, and signaling pathways) in RhoAi treated DRG cells. Furthermore, we assessed in a rat SCI model the in vivo impact of RhoAi treatment administered in situ via alginate scaffold that was combined with FK506 delivery. The improved recovery of locomotion was detected only at the early postinjury time points, whereas after overall survival a dramatic increase of synaptic contacts on outgrowing neurites in affected segments was observed. We validate these results by in vivo proteomic studies along the spinal cord segments from tissue and secreted media analyses, confirming the increase of the synaptogenesis expression factors under RhoAi treatment. Taken together, we demonstrate that RhoAi treatment seems to be useful to stimulate neurite outgrowth in both in vitro as well in vivo environments. However, for in vivo experiments there is a need for sustained delivery regiment to facilitate axon regeneration and promote synaptic reconnections with appropriate target neurons also at chronic phase, which in turn may lead to higher assumption for functional improvement. © 2017 by The American Society for Biochemistry

Force maintenance and myosin filament assembly regulated by Rho-kinase in airway smooth muscle.

PubMed

Lan, Bo; Deng, Linhong; Donovan, Graham M; Chin, Leslie Y M; Syyong, Harley T; Wang, Lu; Zhang, Jenny; Pascoe, Christopher D; Norris, Brandon A; Liu, Jeffrey C-Y; Swyngedouw, Nicholas E; Banaem, Saleha M; Paré, Peter D; Seow, Chun Y

2015-01-01

Smooth muscle contraction can be divided into two phases: the initial contraction determines the amount of developed force and the second phase determines how well the force is maintained. The initial phase is primarily due to activation of actomyosin interaction and is relatively well understood, whereas the second phase remains poorly understood. Force maintenance in the sustained phase can be disrupted by strains applied to the muscle; the strain causes actomyosin cross-bridges to detach and also the cytoskeletal structure to disassemble in a process known as fluidization, for which the underlying mechanism is largely unknown. In the present study we investigated the ability of airway smooth muscle to maintain force after the initial phase of contraction. Specifically, we examined the roles of Rho-kinase and protein kinase C (PKC) in force maintenance. We found that for the same degree of initial force inhibition, Rho-kinase substantially reduced the muscle's ability to sustain force under static conditions, whereas inhibition of PKC had a minimal effect on sustaining force. Under oscillatory strain, Rho-kinase inhibition caused further decline in force, but again, PKC inhibition had a minimal effect. We also found that Rho-kinase inhibition led to a decrease in the myosin filament mass in the muscle cells, suggesting that one of the functions of Rho-kinase is to stabilize myosin filaments. The results also suggest that dissolution of myosin filaments may be one of the mechanisms underlying the phenomenon of fluidization. These findings can shed light on the mechanism underlying deep inspiration induced bronchodilation. Copyright © 2015 the American Physiological Society.

Force maintenance and myosin filament assembly regulated by Rho-kinase in airway smooth muscle

PubMed Central

Lan, Bo; Deng, Linhong; Donovan, Graham M.; Chin, Leslie Y. M.; Syyong, Harley T.; Wang, Lu; Zhang, Jenny; Pascoe, Christopher D.; Norris, Brandon A.; Liu, Jeffrey C.-Y.; Swyngedouw, Nicholas E.; Banaem, Saleha M.; Paré, Peter D.

2014-01-01

Smooth muscle contraction can be divided into two phases: the initial contraction determines the amount of developed force and the second phase determines how well the force is maintained. The initial phase is primarily due to activation of actomyosin interaction and is relatively well understood, whereas the second phase remains poorly understood. Force maintenance in the sustained phase can be disrupted by strains applied to the muscle; the strain causes actomyosin cross-bridges to detach and also the cytoskeletal structure to disassemble in a process known as fluidization, for which the underlying mechanism is largely unknown. In the present study we investigated the ability of airway smooth muscle to maintain force after the initial phase of contraction. Specifically, we examined the roles of Rho-kinase and protein kinase C (PKC) in force maintenance. We found that for the same degree of initial force inhibition, Rho-kinase substantially reduced the muscle's ability to sustain force under static conditions, whereas inhibition of PKC had a minimal effect on sustaining force. Under oscillatory strain, Rho-kinase inhibition caused further decline in force, but again, PKC inhibition had a minimal effect. We also found that Rho-kinase inhibition led to a decrease in the myosin filament mass in the muscle cells, suggesting that one of the functions of Rho-kinase is to stabilize myosin filaments. The results also suggest that dissolution of myosin filaments may be one of the mechanisms underlying the phenomenon of fluidization. These findings can shed light on the mechanism underlying deep inspiration induced bronchodilation. PMID:25305246

The GTP binding proteins Gem and Rad are negative regulators of the Rho–Rho kinase pathway

PubMed Central

Ward, Yvona; Yap, Seow-Fong; Ravichandran, V.; Matsumura, Fumio; Ito, Masaaki; Spinelli, Beth; Kelly, Kathleen

2002-01-01

The cytoskeletal changes that alter cellular morphogenesis and motility depend upon a complex interplay among molecules that regulate actin, myosin, and other cytoskeletal components. The Rho family of GTP binding proteins are important upstream mediators of cytoskeletal organization. Gem and Rad are members of another family of small GTP binding proteins (the Rad, Gem, and Kir family) for which biochemical functions have been mostly unknown. Here we show that Gem and Rad interface with the Rho pathway through association with the Rho effectors, Rho kinase (ROK) α and β. Gem binds ROKβ independently of RhoA in the ROKβ coiled-coil region adjacent to the Rho binding domain. Expression of Gem inhibited ROKβ-mediated phosphorylation of myosin light chain and myosin phosphatase, but not LIM kinase, suggesting that Gem acts by modifying the substrate specificity of ROKβ. Gem or Rad expression led to cell flattening and neurite extension in N1E-115 neuroblastoma cells. In interference assays, Gem opposed ROKβ- and Rad opposed ROKα-mediated cell rounding and neurite retraction. Gem did not oppose cell rounding initiated by ROKβ containing a deletion of the Gem binding region, demonstrating that Gem binding to ROKβ is required for the effects observed. In epithelial or fibroblastic cells, Gem or Rad expression resulted in stress fiber and focal adhesion disassembly. In addition, Gem reverted the anchorage-independent growth and invasiveness of Dbl-transformed fibroblasts. These results identify physiological roles for Gem and Rad in cytoskeletal regulation mediated by ROK. PMID:11956230

Pathophysiology of Post Transplant Hypertension in Kidney Transplant: Focus on Calcineurin Inhibitors Induced Oxidative Stress and Renal Sodium Retention and Implications with RhoA/Rho Kinase Pathway.

PubMed

Calò, Lorenzo A; Ravarotto, Verdiana; Simioni, Francesca; Naso, Elena; Marchini, Francesco; Bonfante, Luciana; Furian, Lucrezia; Rigotti, Paolo

2017-01-01

Post-transplant hypertension is a common occurrence during treatment with calcineurin inhibitors (CNIs) in kidney transplant population. The pathogenesis of vasoconstriction induced by CNIs involves vascular tone alterations and kidney sodium transport regulation. Among the factors involved a key role is played by the activation of intrarenal renin-angiotensin system with enhanced release of Angiotensin II (Ang II) and increase of oxidative stress. A common pathway between oxidative stress and hypertension induced by CNIs may be identified in the involvement of the activation of RhoA/Rho kinase pathway, key for the induction of hypertension and cardiovascular-renal remodeling, of the oxidative stress mediated increased nitric oxide (NO) metabolism and increased renal sodium retention via increased activity of thiazide-sensitive sodium chloride cotransporter (NCC) in the distal tubule. We examined literature data including those coming from our group regarding the role of oxidative stress and sodium retention in CNIs induced hypertension and their involvement in cardiovascular-renal remodeling. Based on the available data, we have provided support to the activation of RhoA/Rho kinase pathway as an important effector in the pathophysiology of CNIs induced post-transplant hypertension via activation of oxidative stress and sodium retention. Clarification of how the biochemical and molecular mechanisms that regulate the processes involved in CNIs induced post transplant hypertension work and interact, would provide further insights not only into the comprehension of the pathophysiology of CNIs induced post transplant hypertension but could also have a positive impact on the clinical ground through the identification of significant targets. Their specific pharmacologic targeting might have multiple beneficial effects on the whole cardiovascular-renal function. The demonstration that in kidney transplanted patients with CNIs induced post-transplanted hypertension, the

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

PubMed

Kutys, Matthew L; Yamada, Kenneth M

2014-09-01

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

Search for Resonant WW and WZ Production in pp̄ Collisions at √s=1.96 TeV

DOE PAGES

Abazov, V. M.; Abbott, B.; Acharya, B. S.; ...

2011-06-29

We search for resonant WW or WZ production by using up to 5.4 fb⁻¹ of integrated luminosity collected by the D0 experiment in run II of the Fermilab Tevatron Collider. The data are consistent with the standard model background expectation, and we set limits on a resonance mass by using the sequential standard model W' boson and the Randall-Sundrum model graviton G as benchmarks. We exclude a sequential standard model W' boson in the mass range 180–690 GeV and a Randall-Sundrum graviton in the range 300–754 GeV at 95% C.L.

Synthesis and characterization of nanocrystalline mordenite, high silica zeolite RHO, and copper faujasite

NASA Astrophysics Data System (ADS)

Hincapie Palacio, Beatriz Omaira

Mordenite is a zeolite that has been used as a selective adsorbent and as a catalyst. In reactions where the diffusion of reagents into the pore system is the rate-determining step, nanoparticles of the catalyst improve the reaction rate. Mordenite with a crystal diameter smaller than 100 nm has been prepared by the modification of different synthetic parameters such as the source of aluminum, the presence of seeds, the use of low temperatures (150°C vs. 170°C), longer crystallization times (24 h vs. 96 h), and different silica to alumina ratios (10--30). The decrease in the crystal diameter of the prepared mordenite was monitored by the application of the Scherrer equation that relates the broadness of the X-ray diffraction peaks to crystal sizes. Zeolite RHO with an initial silica to alumina ratio (SAR) higher than 20 has been prepared. EDTA, citric acid, and tartaric acid have been used as complexing agents in the synthesis of zeolite RHO. Crystallization time increases (from 48 h to 900 h) with increasing the silica to alumina ratios (SAR) of the initial gel (SAR: 10.8 to 30) and by adding complexing agents. Complexing agents favor the formation of small crystals (0.8 mum) with increased silica to alumina ratio (final SAR: 4.5 vs. 4.0 without complexing agents). The products were characterized by XRD, FESEM, EDX, FTIR, and in-situ XRD. Copper containing faujasite has been successfully prepared for the first time using a direct synthesis method. Ammonium hydroxide was used to form a copper complex that was later mixed with the reacting gel. Crystallization took place at 85°C for 11 days. The copper containing faujasite obtained was characterized by XRD, FESEM, EDX, EPR, FTIR, TPR, and BET. According to the XRD pattern only FAU type zeolite was obtained. According to TPR experiments, the reduction temperature for Cu2+ ions present in Cu-FAU prepared by direct synthesis was 70 K higher than for Cu-FAU prepared by ion-exchange. This difference can be due to the

Rho GTPases and p21-activated kinase in the regulation of proliferation and apoptosis by gastrins.

PubMed

He, Hong; Baldwin, Graham S

2008-01-01

Gastrins, including amidated gastrin (Gamide) and glycine-extended gastrin (Ggly), accelerate the growth of gastrointestinal cancer cells by stimulation of proliferation and inhibition of apoptosis. Gamide and Ggly activate different G proteins of the Rho family of small GTPases. For example, Gamide signals Rac/Cdc42 to activate p21-activated kinase 1 while Ggly signals Rho to activate Rho-activated kinase. p21-activated kinase 1 and Rho-activated kinase induce changes in phosphorylation or expression, respectively, of proteins of the Bcl-2 family, which then affect the caspase cascade with consequent inhibition of apoptosis. In addition, interaction of p21-activated kinase 1 with beta-catenin results in phosphorylation of beta-catenin, which enhances its translocation in to the nucleus, activation of TCF4-dependent transcription, and proliferation and migration. The central role of the beta-catenin pathway in carcinogenesis suggests that specific inhibitors of p21-activated kinase 1 may in the future provide novel therapies for gastrointestinal malignancies.

[Tryptase inhibits cell apoptosis through upregulating PAR-2 and Rho kinase in rheumatoid arthritis synovial fibroblasts].

PubMed

Zheng, Qianqian; Li, Shigang; Jia, Yunli; Liu, Wei; Yu, Lingling; Chen, Xianyong; Wang, Jinling

2016-12-01

Objective To investigate the regulatory effects of tryptase on protease-activated receptors 2 (PAR-2), Rho signal pathway and apoptosis of MH7A rheumatoid arthritis synovial fibroblasts. Methods In MH7A cells, the expression of PAR-2 was measured by flow cytometry; cell apoptosis was examined by annexin V- FITC/PI staining combined with flow cytometry; the expression of Rho kinase was detected by Pull-down assay and Western botting. Results Tryptase upregulated the expression of PAR-2 in MH7A cells, and suppressed Fas-mediated apoptosis of MH7A cells in a dose-dependent manner. Meanwhile, PAR-2 inhibitor, FSLLRY-NH2 significantly reduced anti-apoptotic effects of tryptase in MH7A cells, which was related with the increase of activated Rho kinase expression. Conclusion Tryptase plays a role in resistance to the apoptosis of MH7A cells through raising PAR-2 and activating Rho kinase.