scholarly journals Differential expression of KvLQT1 and its regulator IsK in mouse epithelia

2001 ◽  
Vol 280 (2) ◽  
pp. C359-C372 ◽  
Author(s):  
Sophie Demolombe ◽  
Diego Franco ◽  
Piet de Boer ◽  
Sabina Kuperschmidt ◽  
Dan Roden ◽  
...  
Keyword(s):  
Slow Component ◽  
Genetic Disorder ◽  
Expression Patterns ◽  
Resting Potential ◽  
Delayed Rectifier ◽  
Coding Region ◽  
Epithelial Tissues ◽  
In Situ Data ◽  
Adult Mice

KCNQ1 is the human gene responsible in most cases for the long QT syndrome, a genetic disorder characterized by anomalies in cardiac repolarization leading to arrhythmias and sudden death. KCNQ1 encodes a pore-forming K+channel subunit termed KvLQT1 which, in association with its regulatory β-subunit IsK (also called minK), produces the slow component of the delayed-rectifier cardiac K+ current. We used in situ hybridization to localize KvLQT1 and IsK mRNAs in various tissues from adult mice. We showed that KvLQT1 mRNA expression is widely distributed in epithelial tissues, in the absence (small intestine, lung, liver, thymus) or presence (kidney, stomach, exocrine pancreas) of its regulator IsK. In the kidney and the stomach, however, the expression patterns of KvLQT1 and IsK do not coincide. In many tissues, in situ data obtained with the IsK probe coincide with β-galactosidase expression in IsK-deficient mice in which the bacterial lacZgene has been substituted for the IsK coding region. Because expression of KvLQT1 in the presence or absence of its regulator generates a K+ current with different biophysical characteristics, the role of KvLQT1 in epithelial cells may vary depending on the expression of its regulator IsK. The high level of KvLQT1 expression in epithelial tissues is consistent with its potential role in K+secretion and recycling, in maintaining the resting potential, and in regulating Cl− secretion and/or Na+absorption.

Abstract 946: Angiotensin II Type 1 Receptor Partially Mediates Stretch-Induced Potentiation of the Slow Component of Delayed Rectifier Potassium Current in Guinea Pig Atrium

Circulation ◽  
2007 ◽  
Vol 116 (suppl_16) ◽  
Author(s):  
Dimitar P Zankov ◽  
Futoshi Toyoda ◽  
Mariko Omatsu-Kanbe ◽  
Hiroshi Matsuura ◽  
Minoru Horie
Keyword(s):  
Angiotensin Ii ◽  
Guinea Pig ◽  
Action Potential ◽  
Tyrosine Kinases ◽  
Slow Component ◽  
Resting Potential ◽  
Delayed Rectifier ◽  
Antiarrhythmic Action ◽  
Atrial Myocytes ◽  
Membrane Stretch

Introduction: Mechano-sensitive signal transduction in atrial myocytes is closely related to the development of atrial fibrillation (AF). A repolarizing conductance in the heart stimulated by stretch or swelling of myocytes is the slow component of the delayed rectifier K + current ( I Ks ). Modulation of I Ks appears to be linked to pathogenesis of AF because in hereditary cases, gain-of-function mutations in I Ks channel genes have been detected. Moreover, membrane stretch activates AT 1 receptor even without angiotensin II. Hypothesis: We assessed the hypothesis that activation of AT 1 receptor mediates swelling-induced increase of I Ks in atrium. Methods: Whole-cell patch-clamp method was used to record I Ks and action potentials in guinea pig atrial myocytes. Results: Exposure of atrial myocytes to 70% hyposmotic solution (210 mOsmol/L, HS) enhanced I Ks by 84.1± 8.4% ( n = 12), abbreviated atrial action potential at 90% repolarization (APD 90 ) by 16.8± 1.3%, and depolarized resting potential by 4.9±0.7 mV ( n = 9). Selective blockade of AT 1 receptor with 1 or 5 μmol/L candesartan and 5 μmol/L olmesartan significantly attenuated the HS-induced I Ks increase to 48.0±4.1% ( n = 10), 47.2±2.7% ( n = 9), and 59.4±5.5% ( n = 9), respectively. Pretreatment with 5 μmol/L olmesartan also significantly reduced the HS-evoked shortening of APD 90 to 12.4± 1.4% ( n = 10). Tyrosine kinase inhibitors tyrphostins A23 and A25 (20 μmol/L) reduced the HS-induced I Ks enhancement to 42.0± 9.5 ( n = 13) and 52.7±4.7% ( n = 12), respectively, whereas their inactive analogue A1 had little effect. Block of tyrosine phosphatases by 500 μmol/L orthovanadate further promoted the potentiation of I Ks by HS to 124.6± 10.6% ( n = 8) and markedly decreased the recovery rate of I Ks after withdrawal of HS. Pharmacological suppression of G proteins, phospholipase C, and protein kinase C did not appreciably affect the modulation of I Ks . Conclusion: These results indicate involvement of AT 1 receptor and tyrosine kinases in the hyposmotic potentiation of atrial I Ks . It is likely that in the clinical settings, AT 1 receptor antagonists can attenuate the stretch-induced I Ks increase and action potential shortening and thereby exert an acute antiarrhythmic action on stretch-related atrial arrhythmias such as AF.

scholarly journals Molecular Cloning of NHE3 from LLC-PK1 Cells and Localization in Pig Kidney

1999 ◽  
Vol 10 (8) ◽  
pp. 1649-1657
Author(s):  
CHRISTINE A. SHUGRUE ◽  
NICHOLAS OBERMÜLLER ◽  
SEBASTIAN BACHMANN ◽  
CAROLYN W. SLAYMAN ◽  
ROBERT F. REILLY
Keyword(s):  
Species Differences ◽  
Genomic Library ◽  
Expression Patterns ◽  
Northern Analysis ◽  
Kidney Cortex ◽  
Coding Region ◽  
Pig Kidney ◽  
Reverse Transcription Pcr ◽  
Established Line

Abstract. LLC-PK1 cells, an established line from pig kidney, express basolateral and apical Na+/H+ exchangers that can be distinguished by their differing sensitivities to the amiloride analog N-ethyl-N-isopropylamiloride (EIPA). It has been shown previously that the basolateral exchanger is encoded by NHE1. In the present study, a combination of reverse transcription-PCR, 5′ RACE, and genomic library screening was used to clone the coding region of the porcine NHE3 gene. There was significant homology between the LLC-PK1 sequence and the previously reported rabbit and rat NHE3 genes, with nucleotide and deduced amino acid identities of 87 and 85% in rabbit, and 85 and 87% in rat, respectively. To study expression patterns, Northern analysis was carried out using an NHE3 cDNA to probe poly(A)+ RNA isolated from LLC-PK1 cells, and from pig kidney cortex. In all three cases, a major transcript of 6.1 kb was detected along with two minor transcripts of 4.7 and 3.8 kb. In situ hybridization with two different NHE3 probes gave intense labeling of the distal convoluted tubule in pig kidney but (unexpectedly) no detectable labeling of the proximal tubule. These studies suggest that there are marked species differences in NHE3 expression in the distal nephron.

STORM ICE OIL WIND WAVE WATCH SYSTEM (SIOWS): WEB GIS APPLICATION FOR MONITORING THE ARCTIC

2017 ◽  
Author(s):  
Alexander Myasoedov ◽  
Alexander Myasoedov ◽  
Sergey Azarov ◽  
Sergey Azarov ◽  
Ekaterina Balashova ◽  
...  
Keyword(s):  
Satellite Data ◽  
Wind Wave ◽  
Arctic Region ◽  
Web Gis ◽  
The Arctic ◽  
Flexible Tool ◽  
In Situ Data ◽  
Current State ◽  
Watch System

Working with satellite data, has long been an issue for users which has often prevented from a wider use of these data because of Volume, Access, Format and Data Combination. The purpose of the Storm Ice Oil Wind Wave Watch System (SIOWS) developed at Satellite Oceanography Laboratory (SOLab) is to solve the main issues encountered with satellite data and to provide users with a fast and flexible tool to select and extract data within massive archives that match exactly its needs or interest improving the efficiency of the monitoring system of geophysical conditions in the Arctic. SIOWS - is a Web GIS, designed to display various satellite, model and in situ data, it uses developed at SOLab storing, processing and visualization technologies for operational and archived data. It allows synergistic analysis of both historical data and monitoring of the current state and dynamics of the "ocean-atmosphere-cryosphere" system in the Arctic region, as well as Arctic system forecasting based on thermodynamic models with satellite data assimilation.

scholarly journals Critical Dynamics of Defects and Mechanisms of Damage-Failure Transitions in Fatigue

Materials ◽  
2021 ◽  
Vol 14 (10) ◽  
pp. 2554
Author(s):  
Oleg Naimark ◽  
Vladimir Oborin ◽  
Mikhail Bannikov ◽  
Dmitry Ledon
Keyword(s):  
Fatigue Damage ◽  
Kinetic Equations ◽  
Experimental Methodology ◽  
Preliminary Deformation ◽  
Scaling Properties ◽  
In Situ Data ◽  
Number Of Cycles ◽  
Fish Eye ◽  
Very High

An experimental methodology was developed for estimating a very high cycle fatigue (VHCF) life of the aluminum alloy AMG-6 subjected to preliminary deformation. The analysis of fatigue damage staging is based on the measurement of elastic modulus decrement according to “in situ” data of nonlinear dynamics of free-end specimen vibrations at the VHCF test. The correlation of fatigue damage staging and fracture surface morphology was studied to establish the scaling properties and kinetic equations for damage localization, “fish-eye” nucleation, and transition to the Paris crack kinetics. These equations, based on empirical parameters related to the structure of the material, allows us to estimate the number of cycles for the nucleation and advance of fatigue crack.

scholarly journals RNA In Situ Hybridization for Detecting Gene Expression Patterns in the Abdomens and Wings of Drosophila Species

2021 ◽  
Vol 4 (1) ◽  
pp. 20
Author(s):  
Mujeeb Shittu ◽  
Tessa Steenwinkel ◽  
William Dion ◽  
Nathan Ostlund ◽  
Komal Raja ◽  
...  
Keyword(s):  
Gene Expression ◽  
In Situ Hybridization ◽  
Expression Patterns ◽  
Drosophila Species ◽  
Gene Expression Patterns ◽  
Probe Design ◽  
Tissue Preparation ◽  
Design And Synthesis ◽  
Rna In Situ Hybridization

RNA in situ hybridization (ISH) is used to visualize spatio-temporal gene expression patterns with broad applications in biology and biomedicine. Here we provide a protocol for mRNA ISH in developing pupal wings and abdomens for model and non-model Drosophila species. We describe best practices in pupal staging, tissue preparation, probe design and synthesis, imaging of gene expression patterns, and image-editing techniques. This protocol has been successfully used to investigate the roles of genes underlying the evolution of novel color patterns in non-model Drosophila species.

scholarly journals Spatial expression pattern of serine proteases in the blood fluke Schistosoma mansoni determined by fluorescence RNA in situ hybridization

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Lenka Ulrychová ◽  
Pavel Ostašov ◽  
Marta Chanová ◽  
Michael Mareš ◽  
Martin Horn ◽  
...  
Keyword(s):  
In Situ Hybridization ◽  
Schistosoma Mansoni ◽  
Rna Sequencing ◽  
Serine Proteases ◽  
Expression Patterns ◽  
High Sensitivity ◽  
Host Parasite Interactions ◽  
Highly Sensitive ◽  
Host Parasite

Abstract Background The blood flukes of genus Schistosoma are the causative agent of schistosomiasis, a parasitic disease that infects more than 200 million people worldwide. Proteases of schistosomes are involved in critical steps of host–parasite interactions and are promising therapeutic targets. We recently identified and characterized a group of S1 family Schistosoma mansoni serine proteases, including SmSP1 to SmSP5. Expression levels of some SmSPs in S. mansoni are low, and by standard genome sequencing technologies they are marginally detectable at the method threshold levels. Here, we report their spatial gene expression patterns in adult S. mansoni by the high-sensitivity localization assay. Methodology Highly sensitive fluorescence in situ RNA hybridization (FISH) was modified and used for the localization of mRNAs encoding individual SmSP proteases (including low-expressed SmSPs) in tissues of adult worms. High sensitivity was obtained due to specifically prepared tissue and probes in combination with the employment of a signal amplification approach. The assay method was validated by detecting the expression patterns of a set of relevant reference genes including SmCB1, SmPOP, SmTSP-2, and Sm29 with localization formerly determined by other techniques. Results FISH analysis revealed interesting expression patterns of SmSPs distributed in multiple tissues of S. mansoni adults. The expression patterns of individual SmSPs were distinct but in part overlapping and were consistent with existing transcriptome sequencing data. The exception were genes with significantly low expression, which were also localized in tissues where they had not previously been detected by RNA sequencing methods. In general, SmSPs were found in various tissues including reproductive organs, parenchymal cells, esophagus, and the tegumental surface. Conclusions The FISH-based assay provided spatial information about the expression of five SmSPs in adult S. mansoni females and males. This highly sensitive method allowed visualization of low-abundantly expressed genes that are below the detection limits of standard in situ hybridization or by RNA sequencing. Thus, this technical approach turned out to be suitable for sensitive localization studies and may also be applicable for other trematodes. The results suggest that SmSPs may play roles in diverse processes of the parasite. Certain SmSPs expressed at the surface may be involved in host–parasite interactions. Graphic abstract

scholarly journals Measuring and inferring the ice thickness distribution of four glaciers in the Tien Shan, Kyrgyzstan

2020 ◽  
pp. 1-18
Author(s):  
Lander Van Tricht ◽  
Philippe Huybrechts ◽  
Jonas Van Breedam ◽  
Johannes J. Fürst ◽  
Oleg Rybak ◽  
...  
Keyword(s):  
Cross Validation ◽  
Thickness Distribution ◽  
Tien Shan ◽  
Ice Thickness ◽  
Ice Volume ◽  
In Situ Data ◽  
Radio Echo Sounding ◽  
Thickness Measurements ◽  
Tien Shan Mountains

Abstract Glaciers in the Tien Shan mountains contribute considerably to the fresh water used for irrigation, households and energy supply in the dry lowland areas of Kyrgyzstan and its neighbouring countries. To date, reconstructions of the current ice volume and ice thickness distribution remain scarce, and accurate data are largely lacking at the local scale. Here, we present a detailed ice thickness distribution of Ashu-Tor, Bordu, Golubin and Kara-Batkak glaciers derived from radio-echo sounding measurements and modelling. All the ice thickness measurements are used to calibrate three individual models to estimate the ice thickness in inaccessible areas. A cross-validation between modelled and measured ice thickness for a subset of the data is performed to attribute a weight to every model and to assemble a final composite ice thickness distribution for every glacier. Results reveal the thickest ice on Ashu-Tor glacier with values up to 201 ± 12 m. The ice thickness measurements and distributions are also compared with estimates composed without the use of in situ data. These estimates approach the total ice volume well, but local ice thicknesses vary substantially.

scholarly journals Evaluating model parameterizations of submicron aerosol scattering and absorption with in situ data from ARCTAS 2008

2016 ◽  
Vol 16 (14) ◽  
pp. 9435-9455 ◽  
Author(s):  
Matthew J. Alvarado ◽  
Chantelle R. Lonsdale ◽  
Helen L. Macintyre ◽  
Huisheng Bian ◽  
Mian Chin ◽  
...  
Keyword(s):  
Optical Properties ◽  
Size Distribution ◽  
Aerosol Size Distribution ◽  
Visible Radiation ◽  
Submicron Aerosol ◽  
In Situ Data ◽  
Aerosol Absorption ◽  
Aerosol Scattering ◽  
The Impact

Abstract. Accurate modeling of the scattering and absorption of ultraviolet and visible radiation by aerosols is essential for accurate simulations of atmospheric chemistry and climate. Closure studies using in situ measurements of aerosol scattering and absorption can be used to evaluate and improve models of aerosol optical properties without interference from model errors in aerosol emissions, transport, chemistry, or deposition rates. Here we evaluate the ability of four externally mixed, fixed size distribution parameterizations used in global models to simulate submicron aerosol scattering and absorption at three wavelengths using in situ data gathered during the 2008 Arctic Research of the Composition of the Troposphere from Aircraft and Satellites (ARCTAS) campaign. The four models are the NASA Global Modeling Initiative (GMI) Combo model, GEOS-Chem v9-02, the baseline configuration of a version of GEOS-Chem with online radiative transfer calculations (called GC-RT), and the Optical Properties of Aerosol and Clouds (OPAC v3.1) package. We also use the ARCTAS data to perform the first evaluation of the ability of the Aerosol Simulation Program (ASP v2.1) to simulate submicron aerosol scattering and absorption when in situ data on the aerosol size distribution are used, and examine the impact of different mixing rules for black carbon (BC) on the results. We find that the GMI model tends to overestimate submicron scattering and absorption at shorter wavelengths by 10–23 %, and that GMI has smaller absolute mean biases for submicron absorption than OPAC v3.1, GEOS-Chem v9-02, or GC-RT. However, the changes to the density and refractive index of BC in GC-RT improve the simulation of submicron aerosol absorption at all wavelengths relative to GEOS-Chem v9-02. Adding a variable size distribution, as in ASP v2.1, improves model performance for scattering but not for absorption, likely due to the assumption in ASP v2.1 that BC is present at a constant mass fraction throughout the aerosol size distribution. Using a core-shell mixing rule in ASP overestimates aerosol absorption, especially for the fresh biomass burning aerosol measured in ARCTAS-B, suggesting the need for modeling the time-varying mixing states of aerosols in future versions of ASP.

scholarly journals Flux rope axis geometry of magnetic clouds deduced from in situ data

2013 ◽  
Vol 8 (S300) ◽  
pp. 265-268
Author(s):  
Miho Janvier ◽  
Pascal Démoulin ◽  
Sergio Dasso
Keyword(s):  
Interplanetary Medium ◽  
Magnetic Cloud ◽  
Flux Rope ◽  
Magnetic Clouds ◽  
Direct Integration ◽  
Axis Orientation ◽  
In Situ Data ◽  
Geometrical Features ◽  
Wide Range

AbstractMagnetic clouds (MCs) consist of flux ropes that are ejected from the low solar corona during eruptive flares. Following their ejection, they propagate in the interplanetary medium where they can be detected by in situ instruments and heliospheric imagers onboard spacecraft. Although in situ measurements give a wide range of data, these only depict the nature of the MC along the unidirectional trajectory crossing of a spacecraft. As such, direct 3D measurements of MC characteristics are impossible. From a statistical analysis of a wide range of MCs detected at 1 AU by the Wind spacecraft, we propose different methods to deduce the most probable magnetic cloud axis shape. These methods include the comparison of synthetic distributions with observed distributions of the axis orientation, as well as the direct integration of observed probability distribution to deduce the global MC axis shape. The overall shape given by those two methods is then compared with 2D heliospheric images of a propagating MC and we find similar geometrical features.

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