LIVIVO - Search results -

Search results

Result 1 - 10 of total 18

Search options

Article ; Online: Correction: Spatially Resolved Quantification of Chromatin Condensation through Differential Local Rheology in Cell Nuclei Fluorescence Lifetime Imaging.

Spagnol, Stephen T / Dahl, Kris Noel

PloS one

2016 Volume 11, Issue 4, Page(s) e0154639

Abstract: This corrects the article DOI: 10.1371/journal.pone.0146244.]. ...

Abstract	[This corrects the article DOI: 10.1371/journal.pone.0146244.].
Language	English
Publishing date	2016
Publishing country	United States
Document type	Published Erratum
ISSN	1932-6203
ISSN (online)	1932-6203
DOI	10.1371/journal.pone.0154639
Database	MEDical Literature Analysis and Retrieval System OnLINE

Order via subito

This service is chargeable due to the Delivery terms set by subito. Orders including an article and supplementary material will be classified as separate orders. In these cases, fees will be demanded for each order.

Inter-library loan at ZB MED

Your chosen title can be delivered directly to ZB MED Cologne location if you are registered as a user at ZB MED Cologne.

Article ; Online: Spatially Resolved Quantification of Chromatin Condensation through Differential Local Rheology in Cell Nuclei Fluorescence Lifetime Imaging.

Spagnol, Stephen T / Dahl, Kris Noel

PloS one

2016 Volume 11, Issue 1, Page(s) e0146244

Abstract: The linear sequence of DNA encodes access to the complete set of proteins that carry out cellular functions. Yet, much of the functionality appropriate for each cell is nested within layers of dynamic regulation and organization, including a hierarchy of ...

Abstract	The linear sequence of DNA encodes access to the complete set of proteins that carry out cellular functions. Yet, much of the functionality appropriate for each cell is nested within layers of dynamic regulation and organization, including a hierarchy of chromatin structural states and spatial arrangement within the nucleus. There remain limitations in our understanding of gene expression within the context of nuclear organization from an inability to characterize hierarchical chromatin organization in situ. Here we demonstrate the use of fluorescence lifetime imaging microscopy (FLIM) to quantify and spatially resolve chromatin condensation state using cell-permeable, DNA-binding dyes (Hoechst 33342 and PicoGreen). Through in vitro and in situ experiments we demonstrate the sensitivity of fluorescence lifetime to condensation state through the mechanical effects that accompany the structural changes and are reflected through altered viscosity. The establishment of FLIM for resolving and quantifying chromatin condensation state opens the door for single-measurement mechanical studies of the nucleus and for characterizing the role of genome structure and organization in nuclear processes that accompany physiological and pathological changes.
MeSH term(s)	Bacteriophage lambda/genetics ; Cell Nucleus ; Chromatin ; DNA, Viral ; Fluorescent Dyes ; Heterochromatin ; Human Umbilical Vein Endothelial Cells ; Humans ; Microscopy, Fluorescence ; Optical Imaging/methods ; Rheology/methods
Chemical Substances	Chromatin ; DNA, Viral ; Fluorescent Dyes ; Heterochromatin
Language	English
Publishing date	2016-01-14
Publishing country	United States
Document type	Journal Article ; Research Support, U.S. Gov't, Non-P.H.S.
ISSN	1932-6203
ISSN (online)	1932-6203
DOI	10.1371/journal.pone.0146244
Database	MEDical Literature Analysis and Retrieval System OnLINE

Order via subito

Inter-library loan at ZB MED

Your chosen title can be delivered directly to ZB MED Cologne location if you are registered as a user at ZB MED Cologne.

Article ; Online: Chromatin condensation regulates endothelial cell adaptation to shear stress.

Danielsson, Brooke E / Tieu, Katie V / Spagnol, Stephen T / Vu, Kira K / Cabe, Jolene I / Raisch, Tristan B / Dahl, Kris Noel / Conway, Daniel E

Molecular biology of the cell

2022 Volume 33, Issue 11, Page(s) ar101

Abstract: Vascular endothelial cells (ECs) have been shown to be mechanoresponsive to the forces of blood flow, including fluid shear stress (FSS), the frictional force of blood on the vessel wall. Recent reports have shown that FSS induces epigenetic changes in ... ...

Abstract	Vascular endothelial cells (ECs) have been shown to be mechanoresponsive to the forces of blood flow, including fluid shear stress (FSS), the frictional force of blood on the vessel wall. Recent reports have shown that FSS induces epigenetic changes in chromatin. Epigenetic changes, such as methylation and acetylation of histones, not only affect gene expression but also affect chromatin condensation, which can alter nuclear stiffness. Thus, we hypothesized that changes in chromatin condensation may be an important component for how ECs adapt to FSS. Using both in vitro and in vivo models of EC adaptation to FSS, we observed an increase in histone acetylation and a decrease in histone methylation in ECs adapted to flow as compared with static. Using small molecule drugs, as well as vascular endothelial growth factor, to change chromatin condensation, we show that decreasing chromatin condensation enables cells to more quickly align to FSS, whereas increasing chromatin condensation inhibited alignment. Additionally, we show data that changes in chromatin condensation can also prevent or increase DNA damage, as measured by phosphorylation of γH2AX. Taken together, these results indicate that chromatin condensation, and potentially by extension nuclear stiffness, is an important aspect of EC adaptation to FSS.
MeSH term(s)	Acetylation ; Chromatin/metabolism ; Endothelial Cells/metabolism ; Histones/metabolism ; Stress, Mechanical ; Vascular Endothelial Growth Factor A
Chemical Substances	Chromatin ; Histones ; Vascular Endothelial Growth Factor A
Language	English
Publishing date	2022-07-27
Publishing country	United States
Document type	Journal Article ; Research Support, N.I.H., Extramural ; Research Support, Non-U.S. Gov't ; Research Support, U.S. Gov't, Non-P.H.S.
ZDB-ID	1098979-1
ISSN	1939-4586 ; 1059-1524
ISSN (online)	1939-4586
ISSN	1059-1524
DOI	10.1091/mbc.E22-02-0064
Database	MEDical Literature Analysis and Retrieval System OnLINE

Full text online

Accessible to users with ZB MED library card

In stock of ZB MED Cologne/Königswinter

Zs.A 2853: Show issues			Location: Je nach Verfügbarkeit (siehe Angabe bei Bestand) bis Jg. 1994: Bestellungen von Artikeln über das Online-Bestellformular Jg. 1995 - 2021: Lesesall (2.OG) ab Jg. 2022: Lesesaal (EG)
Zs.MO 410: Show issues

Order via subito

Details ▾

Article ; Online: Active cytoskeletal force and chromatin condensation independently modulate intranuclear network fluctuations.

Spagnol, Stephen T / Dahl, Kris Noel

Integrative biology : quantitative biosciences from nano to macro

2014 Volume 6, Issue 5, Page(s) 523–531

Abstract: Chromatin remodeling, including the movement of genes and regulatory factors, precedes or accompanies stimulated changes in gene expression. Here we quantify chromatin fluctuations in primary human cells using particle-tracking microrheology and ... ...

Abstract	Chromatin remodeling, including the movement of genes and regulatory factors, precedes or accompanies stimulated changes in gene expression. Here we quantify chromatin fluctuations in primary human cells using particle-tracking microrheology and determine the physical mechanisms which influence chromatin reorganization. We find that intranuclear movements are enhanced beyond thermal motion by active force generation from cytoskeletal motor activity propagated through the LINC complex; intranuclear movements are also dependent on the viscoelasticity of the DNA-protein polymer network. Chromatin movements were dramatically altered by modulation of chromatin condensation state, which we independently verified using fluorescence lifetime imaging microscopy (FLIM). These findings suggest that chromatin condensation and cytoskeletal force generation play distinct functional roles in regulating intranuclear movements, and these effects are decoupled as measured by particle tracking. We further utilize this approach in identifying the nuclear responsiveness of primary human endothelial cells to vascular endothelial growth factor (VEGF): early in the response chromatin movements increase and are dominated by cytoskeletal force, which transitions at later times to a chromatin decondensation event. Given the hierarchical genome organization in primary cells, our work generally suggests an important role for force generation and chromatin mechanics in altered gene expression kinetics.
MeSH term(s)	Cell Nucleus/physiology ; Chi-Square Distribution ; Chromatin Assembly and Disassembly/physiology ; Cytoskeleton/physiology ; Human Umbilical Vein Endothelial Cells/physiology ; Humans ; Microscopy, Fluorescence ; Rheology ; Vascular Endothelial Growth Factor A/physiology
Chemical Substances	Vascular Endothelial Growth Factor A
Language	English
Publishing date	2014-05
Publishing country	England
Document type	Journal Article ; Research Support, Non-U.S. Gov't ; Research Support, U.S. Gov't, Non-P.H.S.
ZDB-ID	2480063-6
ISSN	1757-9708 ; 1757-9694
ISSN (online)	1757-9708
ISSN	1757-9694
DOI	10.1039/c3ib40226f
Database	MEDical Literature Analysis and Retrieval System OnLINE

Order via subito

Article: Mechanobiology of Chromatin and the Nuclear Interior.

Spagnol, Stephen T / Armiger, Travis J / Dahl, Kris Noel

Cellular and molecular bioengineering

2016 Volume 9, Issue 2, Page(s) 268–276

Abstract: The view of the cell nucleus has evolved from an isolated, static organelle to a dynamic structure integrated with other mechanical elements of the cell. Both dynamics and integration appear to contribute to a mechanical regulation of genome expression. ... ...

Abstract	The view of the cell nucleus has evolved from an isolated, static organelle to a dynamic structure integrated with other mechanical elements of the cell. Both dynamics and integration appear to contribute to a mechanical regulation of genome expression. Here, we review physical structures inside the nucleus at different length scales and the dynamic reorganization modulated by cellular forces. First, we discuss nuclear organization focusing on self-assembly and disassembly of DNA structures and various nuclear bodies. We then discuss the importance of connections from the chromatin fiber through the nuclear envelope to the rest of the cell as they relate to mechanobiology. Finally, we discuss how cell stimulation, both chemical and physical, can alter nuclear structures and ultimately cellular function in healthy cells and in some model diseases. The view of chromatin and nuclear bodies as mechanical entities integrated with force generation from the cytoskeleton combines polymer physics with cell biology and medicine.
Language	English
Publishing date	2016-05-11
Publishing country	United States
Document type	Journal Article
ZDB-ID	2416037-4
ISSN	1865-5033 ; 1865-5025
ISSN (online)	1865-5033
ISSN	1865-5025
DOI	10.1007/s12195-016-0444-9
Database	MEDical Literature Analysis and Retrieval System OnLINE

Full text online

Accessible to users with ZB MED library card

Order via subito

Details ▾
- Full text online
- Order with fees

Article ; Online: Nuclear mechanical resilience but not stiffness is modulated by αII-spectrin.

Armiger, Travis J / Spagnol, Stephen T / Dahl, Kris Noel

Journal of biomechanics

2016 Volume 49, Issue 16, Page(s) 3983–3989

Abstract: Spectrins are multi-domain, elastic proteins that provide elasticity to the plasma membrane of erythrocytes and select nucleated cells. Spectrins have also been found in the nucleus of non-erythrocytes, but their function remains to be uncovered. It has ... ...

Abstract	Spectrins are multi-domain, elastic proteins that provide elasticity to the plasma membrane of erythrocytes and select nucleated cells. Spectrins have also been found in the nucleus of non-erythrocytes, but their function remains to be uncovered. It has been hypothesized that a spring-like spectrin network exists within the lamina nucleoskeleton, however, experiments testing a spectrin network׳s mechanical impact on the nucleus are lacking. Here, we knock-down levels of nuclear αII-spectrin with the goal of disrupting this nucleoskeletal spectrin network. We mechanically test live cells with intranuclear particle tracking and compression assays to probe changes in nuclear mechanics with decreases in αII-spectrin. We show no changes in chromatin mechanics or in the stiffness of nuclei under compression. However, we do observe a reduction in the ability of nuclei with decreased αII-spectrin to recover after compression. These results establish spectrin as a nucleoskeletal component that specifically contributes to elastic recovery after compression.
MeSH term(s)	Cell Nucleus/physiology ; HeLa Cells ; Humans ; Spectrin/physiology ; Stress, Mechanical
Chemical Substances	Spectrin (12634-43-4)
Language	English
Publishing date	2016-12-08
Publishing country	United States
Document type	Journal Article
ZDB-ID	218076-5
ISSN	1873-2380 ; 0021-9290
ISSN (online)	1873-2380
ISSN	0021-9290
DOI	10.1016/j.jbiomech.2016.10.034
Database	MEDical Literature Analysis and Retrieval System OnLINE

In stock of ZB MED Cologne/Königswinter

Zs.A 700: Show issues

Location:
Je nach Verfügbarkeit (siehe Angabe bei Bestand)
bis Jg. 1994: Bestellungen von Artikeln über das Online-Bestellformular
Jg. 1995 - 2021: Lesesall (1.OG)
ab Jg. 2022: Lesesaal (EG)

Order via subito

Details ▾
- See ZB MED holdings
- Order with fees

Article ; Online: Correction

Stephen T Spagnol / Kris Noel Dahl

PLoS ONE, Vol 11, Iss 4, p e

Spatially Resolved Quantification of Chromatin Condensation through Differential Local Rheology in Cell Nuclei Fluorescence Lifetime Imaging.

2016 Volume 0154639

Abstract: This corrects the article DOI:10.1371/journal.pone.0146244.]. ...

Abstract	[This corrects the article DOI:10.1371/journal.pone.0146244.].
Keywords	Medicine ; R ; Science ; Q
Language	English
Publishing date	2016-01-01T00:00:00Z
Publisher	Public Library of Science (PLoS)
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

Full text online

Full text

Inter-library loan at ZB MED

Your chosen title can be delivered directly to ZB MED Cologne location if you are registered as a user at ZB MED Cologne.

Article ; Online: Quantifying site-specific chromatin mechanics and DNA damage response.

Whitefield, Daniel B / Spagnol, Stephen T / Armiger, Travis J / Lan, Li / Dahl, Kris Noel

Scientific reports

2018 Volume 8, Issue 1, Page(s) 18084

Abstract: DNA double-strand breaks pose a direct threat to genomic stability. Studies of DNA damage and chromatin dynamics have yielded opposing results that support either increased or decreased chromatin motion after damage. In this study, we independently ... ...

Abstract	DNA double-strand breaks pose a direct threat to genomic stability. Studies of DNA damage and chromatin dynamics have yielded opposing results that support either increased or decreased chromatin motion after damage. In this study, we independently measure the dynamics of transcriptionally active or repressed chromatin regions using particle tracking microrheology. We find that the baseline motion of transcriptionally repressed regions of chromatin are significantly less mobile than transcriptionally active chromatin, which is statistically similar to the bulk motion of chromatin within the nucleus. Site specific DNA damage using KillerRed tags induced in loci within repressed chromatin causes an increased motion, while loci within transcriptionally active regions remains unchanged at similar time scales. We also observe a time-dependent response associated with a further increase in chromatin decondensation. Global induction of damage with bleocin displays similar trends of chromatin decondensation and increased mobility only at 53BP1-labeled damage sites but not at non-damaged sites, indicating that chromatin dynamics are tightly regulated locally after damage. These results shed light on the evolution of the local and global DNA damage response associated with chromatin remodeling and dynamics, with direct implications for their role in repair.
MeSH term(s)	Cell Line, Tumor ; Cell Nucleus/genetics ; Chromatin/genetics ; Chromatin Assembly and Disassembly ; DNA Breaks, Double-Stranded ; DNA Damage ; Genes, Reporter ; Humans ; Transcriptional Activation
Chemical Substances	Chromatin
Language	English
Publishing date	2018-12-27
Publishing country	England
Document type	Journal Article ; Research Support, N.I.H., Extramural ; Research Support, U.S. Gov't, Non-P.H.S.
ZDB-ID	2615211-3
ISSN	2045-2322 ; 2045-2322
ISSN (online)	2045-2322
ISSN	2045-2322
DOI	10.1038/s41598-018-36343-x
Database	MEDical Literature Analysis and Retrieval System OnLINE

Order via subito

Article ; Online: Spatially Resolved Quantification of Chromatin Condensation through Differential Local Rheology in Cell Nuclei Fluorescence Lifetime Imaging.

Stephen T Spagnol / Kris Noel Dahl

PLoS ONE, Vol 11, Iss 1, p e

2016 Volume 0146244

Abstract	The linear sequence of DNA encodes access to the complete set of proteins that carry out cellular functions. Yet, much of the functionality appropriate for each cell is nested within layers of dynamic regulation and organization, including a hierarchy of chromatin structural states and spatial arrangement within the nucleus. There remain limitations in our understanding of gene expression within the context of nuclear organization from an inability to characterize hierarchical chromatin organization in situ. Here we demonstrate the use of fluorescence lifetime imaging microscopy (FLIM) to quantify and spatially resolve chromatin condensation state using cell-permeable, DNA-binding dyes (Hoechst 33342 and PicoGreen). Through in vitro and in situ experiments we demonstrate the sensitivity of fluorescence lifetime to condensation state through the mechanical effects that accompany the structural changes and are reflected through altered viscosity. The establishment of FLIM for resolving and quantifying chromatin condensation state opens the door for single-measurement mechanical studies of the nucleus and for characterizing the role of genome structure and organization in nuclear processes that accompany physiological and pathological changes.
Keywords	Medicine ; R ; Science ; Q
Subject code	612 ; 571
Language	English
Publishing date	2016-01-01T00:00:00Z
Publisher	Public Library of Science (PLoS)
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

Full text online

Full text

Inter-library loan at ZB MED

Your chosen title can be delivered directly to ZB MED Cologne location if you are registered as a user at ZB MED Cologne.

Article: Active cytoskeletal force and chromatin condensation independently modulate intranuclear network fluctuations

Spagnol, Stephen T / Noel Dahl, Kris

Integrative biology. 2014 Apr. 22, v. 6, no. 5

2014

Abstract	Chromatin remodeling, including the movement of genes and regulatory factors, precedes or accompanies stimulated changes in gene expression. Here we quantify chromatin fluctuations in primary human cells using particle-tracking microrheology and determine the physical mechanisms which influence chromatin reorganization. We find that intranuclear movements are enhanced beyond thermal motion by active force generation from cytoskeletal motor activity propagated through the LINC complex; intranuclear movements are also dependent on the viscoelasticity of the DNA–protein polymer network. Chromatin movements were dramatically altered by modulation of chromatin condensation state, which we independently verified using fluorescence lifetime imaging microscopy (FLIM). These findings suggest that chromatin condensation and cytoskeletal force generation play distinct functional roles in regulating intranuclear movements, and these effects are decoupled as measured by particle tracking. We further utilize this approach in identifying the nuclear responsiveness of primary human endothelial cells to vascular endothelial growth factor (VEGF): early in the response chromatin movements increase and are dominated by cytoskeletal force, which transitions at later times to a chromatin decondensation event. Given the hierarchical genome organization in primary cells, our work generally suggests an important role for force generation and chromatin mechanics in altered gene expression kinetics.
Keywords	chromatin ; cytoskeleton ; endothelial cells ; fluorescence microscopy ; gene expression ; gene expression regulation ; genes ; humans ; mechanics ; polymers ; vascular endothelial growth factors ; viscoelasticity
Language	English
Dates of publication	2014-0422
Size	p. 523-531.
Publishing place	The Royal Society of Chemistry
Document type	Article
ZDB-ID	2480063-6
ISSN	1757-9708 ; 1757-9694
ISSN (online)	1757-9708
ISSN	1757-9694
DOI	10.1039/c3ib40226f
Database	NAL-Catalogue (AGRICOLA)

Order via subito

To top

More links

Kategorien

Order via subito

Inter-library loan at ZB MED

More links

Kategorien

Order via subito

Inter-library loan at ZB MED

Full text online

More links

Kategorien

In stock of ZB MED Cologne/Königswinter

Order via subito

More links

Kategorien

Order via subito

Full text online

More links

Kategorien

Order via subito

More links

Kategorien

In stock of ZB MED Cologne/Königswinter

Order via subito

Full text online

More links

Kategorien

Inter-library loan at ZB MED

More links

Kategorien

Order via subito

Full text online

More links

Kategorien

Inter-library loan at ZB MED

More links

Kategorien

Order via subito