scholarly journals Surface view of the lateral organization of lipids and proteins in lung surfactant model systems—A ToF-SIMS approach

2010 ◽  
Vol 1798 (4) ◽  
pp. 730-740 ◽  
Author(s):  
Mohammed Saleem ◽  
Hans-Joachim Galla
Keyword(s):  
Lung Surfactant ◽  
Model Systems ◽  
Surface View ◽  
Tof Sims ◽  
Lateral Organization

scholarly journals Critical Phenomena in Plasma Membrane Organization and Function

2020 ◽  
Vol 72 (1) ◽  
Author(s):  
Thomas R. Shaw ◽  
Subhadip Ghosh ◽  
Sarah L. Veatch
Keyword(s):  
Plasma Membrane ◽  
Critical Phenomena ◽  
Model Systems ◽  
Annual Review ◽  
Publication Date ◽  
Membrane Composition ◽  
Lipid Organization ◽  
And Function ◽  
Lateral Organization ◽  
Liquid Liquid Phase Separation

Lateral organization in the plane of the plasma membrane is an important driver of biological processes. The past dozen years have seen increasing experimental support for the notion that lipid organization plays an important role in modulating this heterogeneity. Various biophysical mechanisms rooted in the concept of liquid–liquid phase separation have been proposed to explain diverse experimental observations of heterogeneity in model and cell membranes with distinct but overlapping applicability. In this review, we focus on the evidence for and the consequences of the hypothesis that the plasma membrane is poised near an equilibrium miscibility critical point. Critical phenomena explain certain features of the heterogeneity observed in cells and model systems but also go beyond heterogeneity to predict other interesting phenomena, including responses to perturbations in membrane composition. Expected final online publication date for the Annual Review of Physical Chemistry, Volume 72 is April 20, 2021. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

Biophysical Investigation of Nanoparticle Interactions with Lung Surfactant Model Systems

2006 ◽  
Vol 2 (3) ◽  
pp. 245-252 ◽  
Author(s):  
Diana Stuart ◽  
Raimar Löbenberg ◽  
Tabitha Ku ◽  
Shirzad Azarmi ◽  
Leticia Ely ◽  
...  
Keyword(s):  
Lung Surfactant ◽  
Model Systems ◽  
Nanoparticle Interactions

Size Dependent Interactions of Nanoparticles with Lung Surfactant Model Systems and the Significant Impact on Surface Potential

2008 ◽  
Vol 8 (6) ◽  
pp. 2971-2978 ◽  
Author(s):  
Tabitha Ku ◽  
Simardeep Gill ◽  
Raimar Löbenberg ◽  
Shirzad Azarmi ◽  
Wilson Roa ◽  
...  
Keyword(s):  
Surface Potential ◽  
Surface Pressure ◽  
High Surface ◽  
Lung Surfactant ◽  
Drug Carriers ◽  
Model Systems ◽  
Optimal Size ◽  
Surfactant Film ◽  
Pressure Area ◽  
The Relationship

The relationship between a model pulmonary surfactant system and various sized nanoparticles was investigated in this study. Diplamitoylphosphatidylcholine (DPPC) is the main lipid constituent of lung surfactant and has the ability to reach very high surface pressures (around 70 mN/m) upon compression. Due to these properties it was used as a model to simulate the lung surfactant film in vitro. The first objective of this study was to investigate the relationship between DPPC and various sized nanoparticles within the subphase through surface pressure—area isotherms. The second objective was to measure the surface potential of the different preparations (conducted on a mini-Langmuir trough) and to determine if an optimal nanoparticle size exists possessing a greater affinity for the DPPC film compared to other sizes. The results from the pressure area isotherms indicate that the interaction between DPPC and the nanoparticles is stable and that the 235 nm particles may represent an optimal size. Furthermore, the results from the surface potential experiments confirm that an interaction of the nanoparticles with the monolayer exists as indicated by surface-pressure area isotherms. Any even moderate interaction between nanoparticles and lung surfactant film might reduce or increase the surface potential of the surfactant film, and this might impact the deposition of the nanoparticles or other ligands which may be positively or negatively charged drugs within the surfactant film. Thus changes in surface potential due to nanoparticle interactions have to be taken into account for future drug targeting studies using nano-sized drug carriers.

ToF-SIMS Imaging of Lipid/Protein Model Systems

2014 ◽  
pp. 19-43
Author(s):  
Michael Seifert ◽  
Mohammed Saleem ◽  
Daniel Breitenstein ◽  
Hans-Joachim Galla ◽  
Michaela C. Meyer
Keyword(s):  
Model Systems ◽  
Tof Sims ◽  
Protein Model

scholarly journals Size Influences the Effect of Hydrophobic Nanoparticles on Lung Surfactant Model Systems

2014 ◽  
Vol 106 (1) ◽  
pp. 289-298 ◽  
Author(s):  
Mridula V. Dwivedi ◽  
Rakesh Kumar Harishchandra ◽  
Olga Koshkina ◽  
Michael Maskos ◽  
Hans-Joachim Galla
Keyword(s):  
Lung Surfactant ◽  
Model Systems

Differential regulation of SP-A1 and SP-A2 genes by cAMP, glucocorticoids, and insulin

1998 ◽  
Vol 274 (2) ◽  
pp. L177-L185 ◽  
Author(s):  
A. R. Kumar ◽  
J. M. Snyder
Keyword(s):  
Cell Line ◽  
Lung Surfactant ◽  
Protein A ◽  
Fetal Lung ◽  
Surfactant Protein ◽  
Model Systems ◽  
Mrna Levels ◽  
Mrna Transcripts ◽  
Lung Surfactant Protein ◽  
Human Fetal Lung

In the human fetal lung, surfactant protein A (SP-A) is encoded by two highly similar genes, SP-A1 and SP-A2, which are developmentally and hormonally regulated. Using primer extension analysis, we evaluated the levels of SP-A1 and SP-A2 mRNA transcripts in human fetal lung explants and in a human adult lung adenocarcinoma cell line (H441 cells) cultured in the absence or presence of either dibutyryladenosine 3′,5′-cyclic monophosphate (DBcAMP, 1 mM), dexamethasone (10−7 M), or insulin (2.5 μg/ml). In the human fetal lung explants, the content of SP-A1 mRNA was approximately four times that of SP-A2 mRNA. DBcAMP increased SP-A1 mRNA levels by 100% and SP-A2 mRNA levels by 500%, thus reducing the ratio of SP-A1 mRNA to SP-A2 mRNA to ∼1:1. Dexamethasone inhibited all of the SP-A1 and SP-A2 mRNA transcripts to the same extent, by ∼70%, whereas insulin inhibited all SP-A mRNA transcripts by ∼60%. The ratio of SP-A1 to SP-A2 mRNA in dexamethasone- or insulin-treated explants was the same as the ratio observed in controls. In the H441 cells, SP-A1 mRNA levels were ∼1.5 times that of SP-A2 mRNA levels. DBcAMP increased both SP-A1 and SP-A2 mRNA levels by 100%. Dexamethasone inhibited SP-A1 mRNA levels in the cell line by 60%, whereas SP-A2 mRNA levels were not significantly affected. Insulin inhibited SP-A1 mRNA levels in the cell line by 40% without affecting SP-A2 mRNA levels. These findings suggest that the two human SP-A genes are regulated differently in the two model systems.

scholarly journals A ToF-SIMS study of the lateral organization of lipids and proteins in pulmonary surfactant systems

2011 ◽  
Vol 1808 (3) ◽  
pp. 614-621 ◽  
Author(s):  
Eleonora Keating ◽  
Alan J. Waring ◽  
Frans J. Walther ◽  
Fred Possmayer ◽  
Ruud A.W. Veldhuizen ◽  
...  
Keyword(s):  
Pulmonary Surfactant ◽  
Tof Sims ◽  
Surfactant Systems ◽  
Lateral Organization

scholarly journals Analysis of Lung Surfactant Model Systems with Time-of-Flight Secondary Ion Mass Spectrometry

2000 ◽  
Vol 79 (1) ◽  
pp. 357-369 ◽  
Author(s):  
Nikolaus Bourdos ◽  
Felix Kollmer ◽  
Alfred Benninghoven ◽  
Michaela Ross ◽  
Manfred Sieber ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Secondary Ion Mass Spectrometry ◽  
Lung Surfactant ◽  
Time Of Flight ◽  
Model Systems ◽  
Ion Mass Spectrometry ◽  
Secondary Ion

Applications of Time-OF-Flight Secondary Ion Mass Spectrometry (TOF-SIMS)

1990 ◽  
Vol 48 (2) ◽  
pp. 308-309
Author(s):  
Bruno Schueler ◽  
Robert W. Odom
Keyword(s):  
Mass Spectrometry ◽  
Secondary Ion Mass Spectrometry ◽  
Structural Information ◽  
Time Of Flight ◽  
Biological Tissues ◽  
Polymer Surfaces ◽  
Tof Sims ◽  
Secondary Ions ◽  
Ion Mass Spectrometry ◽  
Secondary Ion

Time-of-flight secondary ion mass spectrometry (TOF-SIMS) provides unique capabilities for elemental and molecular compositional analysis of a wide variety of surfaces. This relatively new technique is finding increasing applications in analyses concerned with determining the chemical composition of various polymer surfaces, identifying the composition of organic and inorganic residues on surfaces and the localization of molecular or structurally significant secondary ions signals from biological tissues. TOF-SIMS analyses are typically performed under low primary ion dose (static SIMS) conditions and hence the secondary ions formed often contain significant structural information.This paper will present an overview of current TOF-SIMS instrumentation with particular emphasis on the stigmatic imaging ion microscope developed in the authors’ laboratory. This discussion will be followed by a presentation of several useful applications of the technique for the characterization of polymer surfaces and biological tissues specimens. Particular attention in these applications will focus on how the analytical problem impacts the performance requirements of the mass spectrometer and vice-versa.

Nuclear coiled bodies and the nucleolus

1994 ◽  
Vol 52 ◽  
pp. 20-21
Author(s):  
K. Brasch ◽  
J. Williams ◽  
D. Gallo ◽  
T. Lee ◽  
R. L. Ochs
Keyword(s):  
Mouse Liver ◽  
Nuclear Body ◽  
Nuclear Bodies ◽  
Model Systems ◽  
Coiled Body ◽  
Rrna Processing ◽  
Malignant Cells ◽  
Sm Proteins ◽  
Coiled Bodies ◽  
Unique Protein

Though first described in 1903 by Ramon-y-Cajal as silver-staining “accessory bodies” to nucleoli, nuclear bodies were subsequently rediscovered by electron microscopy about 30 years ago. Nuclear bodies are ubiquitous, but seem most abundant in hyperactive and malignant cells. The best studied type of nuclear body is the coiled body (CB), so termed due to characteristic morphology and content of a unique protein, p80-coilin (Fig.1). While no specific functions have as yet been assigned to CBs, they contain spliceosome snRNAs and proteins, and also the nucleolar protein fibrillarin. In addition, there is mounting evidence that CBs arise from or are generated near the nucleolus and then migrate into the nucleoplasm. This suggests that as yet undefined links may exist, between nucleolar pre-rRNA processing events and the spliceosome-associated Sm proteins in CBs.We are examining CB and nucleolar changes in three diverse model systems: (1) estrogen stimulated chick liver, (2) normal and neoplastic cells, and (3) polyploid mouse liver.

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