scholarly journals Active and Repressive Chromatin-Associated Proteome after MPA Treatment and the Role of Midkine in Epithelial Monolayer Permeability

2016 ◽  
Vol 17 (4) ◽  
pp. 597 ◽  
Author(s):  
Niamat Khan ◽  
Christof Lenz ◽  
Lutz Binder ◽  
Dasaradha Pantakani ◽  
Abdul Asif
Keyword(s):  
Epithelial Monolayer ◽  
Repressive Chromatin ◽  
Monolayer Permeability

scholarly journals Modelling the role of the basement membrane beneath a growing epithelial monolayer

2012 ◽  
Vol 298 ◽  
pp. 82-91 ◽  
Author(s):  
Sara-Jane Dunn ◽  
Alexander G. Fletcher ◽  
S. Jonathan Chapman ◽  
David J. Gavaghan ◽  
James M. Osborne
Keyword(s):  
Basement Membrane ◽  
Epithelial Monolayer

Intestinal mucosal barrier dysfunction in SAP patients with MODS ameliorated by continuous blood purification

2017 ◽  
Vol 41 (1) ◽  
pp. 43-51
Author(s):  
Qing Shen ◽  
Zhengrong Li ◽  
Shanshan Huang ◽  
Liman Li ◽  
Hua Gan ◽  
...  
Keyword(s):  
Mrna Expression ◽  
Mucosal Barrier ◽  
Intestinal Epithelial ◽  
Barrier Dysfunction ◽  
Intestinal Mucosal Barrier ◽  
Epithelial Monolayer ◽  
Tnf Α ◽  
Monolayer Permeability ◽  
Α Level ◽  
Junction Proteins

Background: Dysfunction of the intestinal mucosal barrier plays an important role in the pathophysiology of severe acute pancreatitis (SAP). Continuous blood purification (CBP) has been shown to improve the prognosis of SAP patients. In order to investigate the effect of CBP on intestinal mucosal barrier dysfunction in SAP patients with MODS, we conducted in vivo and in vitro experiments to explore the underlying mechanisms. Methods: The markers for the assessment of intestinal mucosal barrier function including serum diamine oxidase (DAO), endotoxin and intestinal epithelial monolayer permeability were detected during CBP therapy. The distribution and expression of cytoskeleton protein F-actin and tight junction proteins claudin-1 were observed. In addition, Rho kinase (ROCK) mRNA expression and serum tumor necrosis factor-alpha (TNF-α) levels during CBP were determined. Results: SAP patients with MODS had increased levels of serum DAO, endotoxin and intestinal epithelial monolayer permeability when compared with normal controls. While the distribution of F-actin and claudin-1 was rearranged, and the expression of claudin-1 significantly decreased, but F-actin had no change. Meanwhile, ROCK mRNA expression and serum TNF-α level were increased. However, after CBP treatment, levels of serum DAO, endotoxin and intestinal epithelial monolayer permeability decreased. The F-actin and claudin-1 reorganization attenuated and the expression of claudin-1 increased. At the same time, ROCK mRNA expression and serum TNF-α level were decreased. Conclusions: CBP can effectively improve intestinal mucosal barrier dysfunction. The beneficial effect is associated with the improvement of cytoskeleton and tight junction proteins in stability by downregulation of ROCK mRNA expression through the removal of excess proinflammatory factors.

scholarly journals Genome-wide maps of nucleolus interactions reveal distinct layers of repressive chromatin domains

2020 ◽  
Author(s):  
Cristiana Bersaglieri ◽  
Jelena Kresoja-Rakic ◽  
Shivani Gupta ◽  
Dominik Bär ◽  
Rostyslav Kuzyakiv ◽  
...  
Keyword(s):  
Nuclear Periphery ◽  
Interaction Strength ◽  
Nuclear Lamina ◽  
Nuclear Space ◽  
Chromosome Architecture ◽  
Neural Genes ◽  
Repressive Chromatin ◽  
Genome Wide ◽  
Nuclear Environment

AbstractEukaryotic chromosomes are folded into hierarchical domains, enabling the organization of the genome into functional compartments. Nuclear periphery and nucleolus are two nuclear landmarks thought to contribute to repressive chromosome architecture. However, while the role of nuclear lamina (NL) in genome organization has been well documented, the function of the nucleolus remains under-investigated due to the lack of methods for genome-wide maps of nucleolar associated domains (NADs). Here we established a method based on a Dam-fused engineered nucleolar histone H2B that marks DNA contacting the nucleolus. NAD-maps of ESCs and neural progenitors revealed layers of genome compartmentalization with distinct, repressive chromatin states based on the interaction with the nucleolus, NL, or both. NADs showed higher H3K9me2 and lower H3K27me3 content than regions exclusively interacting with NL. Upon ESC differentiation, chromosomes around the nucleolus acquire a more compact, rigid architecture whereas NADs specific for ESCs decrease their interaction strength within the repressive B-compartment strength, unlocking neural genes from repressive nuclear environment. The methodologies here developed will make possible to include the contribution of the nucleolus in future studies investigating the relationship between nuclear space and genome function.

scholarly journals Intestinal Epithelial Monolayer Permeability of Sweet Potato-Derived Anthocyanin and Carotenoid Extracts in Caco-2 Cells

2021 ◽  
Vol 50 (8) ◽  
pp. 765-773
Author(s):  
Woo Sung Park ◽  
Kyung Ah Koo ◽  
Hye-Jin Kim ◽  
Ji-Min Kwon ◽  
Dong-Min Kang ◽  
...  
Keyword(s):  
Sweet Potato ◽  
Intestinal Epithelial ◽  
Epithelial Monolayer ◽  
Monolayer Permeability

scholarly journals Role of Extracellular Vimentin in Cancer-Cell Functionality and Its Influence on Cell Monolayer Permeability Changes Induced by SARS-CoV-2 Receptor Binding Domain

2021 ◽  
Vol 22 (14) ◽  
pp. 7469
Author(s):  
Divyendu Goud Thalla ◽  
Philipp Jung ◽  
Markus Bischoff ◽  
Franziska Lautenschläger
Keyword(s):  
Cell Surface ◽  
Receptor Binding ◽  
Cell Monolayer ◽  
Binding Domain ◽  
Spike Protein ◽  
Outer Cell ◽  
Receptor Binding Domain ◽  
Monolayer Permeability ◽  
Mcf 7

The cytoskeletal protein vimentin is secreted under various physiological conditions. Extracellular vimentin exists primarily in two forms: attached to the outer cell surface and secreted into the extracellular space. While surface vimentin is involved in processes such as viral infections and cancer progression, secreted vimentin modulates inflammation through reduction of neutrophil infiltration, promotes bacterial elimination in activated macrophages, and supports axonal growth in astrocytes through activation of the IGF-1 receptor. This receptor is overexpressed in cancer cells, and its activation pathway has significant roles in general cellular functions. In this study, we investigated the functional role of extracellular vimentin in non-tumorigenic (MCF-10a) and cancer (MCF-7) cells through the evaluation of its effects on cell migration, proliferation, adhesion, and monolayer permeability. Upon treatment with extracellular recombinant vimentin, MCF-7 cells showed increased migration, proliferation, and adhesion, compared to MCF-10a cells. Further, MCF-7 monolayers showed reduced permeability, compared to MCF-10a monolayers. It has been shown that the receptor binding domain of SARS-CoV-2 spike protein can alter blood–brain barrier integrity. Surface vimentin also acts as a co-receptor between the SARS-CoV-2 spike protein and the cell-surface angiotensin-converting enzyme 2 receptor. Therefore, we also investigated the permeability of MCF-10a and MCF-7 monolayers upon treatment with extracellular recombinant vimentin, and its modulation of the SARS-CoV-2 receptor binding domain. These findings show that binding of extracellular recombinant vimentin to the cell surface enhances the permeability of both MCF-10a and MCF-7 monolayers. However, with SARS-CoV-2 receptor binding domain addition, this effect is lost with MCF-7 monolayers, as the extracellular vimentin binds directly to the viral domain. This defines an influence of extracellular vimentin in SARS-CoV-2 infections.

scholarly journals Functional redundancy of variant and canonical histone H3 lysine 9 modification in Drosophila

2017 ◽  
Author(s):  
Taylor J.R. Penke ◽  
Daniel J. McKay ◽  
Brian D. Strahl ◽  
A. Gregory Matera ◽  
Robert J. Duronio
Keyword(s):  
Gene Activation ◽  
Histone H3 ◽  
Histone Variants ◽  
Protein Coding ◽  
Post Translational Modifications ◽  
Histone Ptms ◽  
Repressive Chromatin ◽  
Expression Of Genes ◽  
Canonical Histone

ABSTRACTHistone post-translational modifications (PTMs) and differential incorporation of variant and canonical histones into chromatin are central modes of epigenetic regulation. Despite similar protein sequences, histone variants are enriched for different suites of PTMs compared to their canonical counterparts. For example, variant histone H3.3 occurs primarily in transcribed regions and is enriched for “active” histone PTMs like Lys9 acetylation (H3.3K9ac), whereas the canonical histone H3 is enriched for Lys9 methylation (H3K9me), which is found in transcriptionally silent heterochromatin. To determine the functions of K9 modification on variant versus canonical H3, we compared the phenotypes caused by engineering H3.3K9R and H3K9R mutant genotypes in Drosophila melanogaster. Whereas most H3.3K9R and a small number of H3K9R mutant animals are capable of completing development and do not have substantially altered protein coding transcriptomes, all H3.3K9RH3K9R combined mutants die soon after embryogenesis and display decreased expression of genes enriched for K9ac. These data suggest that the role of K9ac in gene activation during development can be provided by either H3 or H3.3. Conversely, we found that H3.3K9 is methylated at telomeric transposons, and this mark contributes to repressive chromatin architecture, supporting a role for H3.3 in heterochromatin that is distinct from that of H3. Thus, our genetic and molecular analyses demonstrate that K9 modification of variant and canonical H3 have overlapping roles in development and transcriptional regulation, though to differing extents in euchromatin and heterochromatin.

scholarly journals Promoter-intrinsic and local chromatin features determine gene repression in lamina-associated domains

2018 ◽  
Author(s):  
Christ Leemans ◽  
Marloes van der Zwalm ◽  
Laura Brueckner ◽  
Federico Comoglio ◽  
Tom van Schaik ◽  
...  
Keyword(s):  
General Framework ◽  
Transcription Elongation ◽  
Promoter Sequence ◽  
Gene Repression ◽  
List Type ◽  
Promoter Strength ◽  
Repressive Chromatin ◽  
Systematic Understanding ◽  
Genomic Locations

AbstractIt is largely unclear whether genes that are naturally embedded in lamina associated domains (LADs) are inactive due to their chromatin environment, or whether LADs are merely secondary to the lack of transcription. We show that hundreds of human promoters become active when moved from their native LAD position to a neutral context in the same cells, indicating that LADs form a repressive environment. Another set of promoters inside LADs is able to "escape" repression, although their transcription elongation is attenuated. By inserting reporters into thousands of genomic locations, we demonstrate that these escaper promoters are intrinsically less sensitive to LAD repression. This is not simply explained by promoter strength, but by the interplay between promoter sequence and local chromatin features that vary strongly across LADs. Enhancers also differ in their sensitivity to LAD chromatin. This work provides a general framework for the systematic understanding of gene regulation by repressive chromatin.HighlightsTwo promoter transplantation strategies elucidate the regulatory role of LAD chromatinLADs are generally repressive, but also highly heterogeneousLADs can impede both promoter activity and transcription elongationPromoters vary intrinsically in their sensitivity to LAD repression

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