Search results for " differentiation"

Unjamming overcomes kinetic and proliferation arrest in terminally differentiated cells and promotes collective motility of carcinoma

2018

Under homeostatic conditions, mature epithelia are locked in a kinetically-silent, jammed state. During wound repair or branching morphogenesis epithelia must unjam and acquire liquid-like properties. These events might be recapitulated in the transition from in situ to invasive cancer stages. How cells control this transition and how biologically relevant it is, however, remains unclear. Recently, we showed that altering RAB5A levels, a master regulator of endosomal trafficking, is sufficient to re-awaken motility in jammed epithelia, through ill-defined, endocytic-sensitive biochemical pathways. Here, we show that RAB5A promotes non-clathrin-dependent internalization of epidermal growth f…

The geochemistry of Tl and its isotopes during magmatic and hydrothermal processes: The peralkaline Ilimaussaq complex, southwest Greenland

2014

Abstract We use thallium (Tl) concentrations, K/Rb, K/Tl and Rb/Tl ratios and Tl isotopes in minerals from the alkaline to peralkaline Ilimaussaq complex (South Greenland) to trace magmatic differentiation, crustal assimilation, magmatic degassing, ore precipitation and hydrothermal metasomatism. Closed-system magmatic differentiation is marked by a coherent decrease of K/Tl- and K/Rb-ratios, whereas crustal assimilation results in a strong Tl-enrichment, causing low K/Tl-ratios compared to K/Rb-ratios. Thallium isotopes show only slight changes during orthomagmatic differentiation and the assimilation of crustal material cannot be traced, since the isotopic composition of the average crust…

A long non-coding RNA controls parasite differentiation in African trypanosomes

2020

Trypanosoma bruceicauses African sleeping sickness, a fatal human disease. Its differentiation from replicative slender form into quiescent stumpy form promotes host survival and parasite transmission. Long noncoding RNAs (lncRNAs) are known to regulate cell differentiation. To determine whether lncRNAs are involved in parasite differentiation we used RNAseq to survey theT. bruceilncRNA gene repertoire, identifying 1,428 previously uncharacterized lncRNA genes. We analysedgrumpy, a lncRNA located immediately upstream of an RNA-binding protein that is akeydifferentiation regulator. Grumpy over-expression resulted in premature parasite differentiation into the quiescent stumpy form, and subse…

Changes in the density of microtubular networks in mesophyll cells and mesophyll derived protoplasts of Nicotiana and Triticum during leaf development

1993

Changes in the density of microtubular mesh-works were analysed in mesophyll cells and mesophyll derived protoplasts of Nicotiana tabacum L. and Triticum aestivum L. during leaf development. The main purpose of this study was to test whether the low density, if not lack, of microtubular networks recently described in protoplasts that had been isolated from fully differentiated mesophyll cells happened during protoplast isolation or whether the loss of microtubules actually occurred during differentiation of the leaf tissue. Immunofluorescence microscopy showed that the density of the microtubular cytoskeleton in the leaf tissue decreased steadily after cessation of cell growth in both speci…

Pattern of polyamines and related monoacetyl derivatives in chick embryo retina during development.

1994

Polyamines and related monoacetyl derivatives were studied in chick embryo retina during development (6th-19th day). Putrescine, which is high in the first phase of retinogenesis, is necessary to sustain both tissue proliferation and via N-acetylputrescine, gamma-aminobutyric acid synthesis. A later increase in spermidine and particularly spermine may play a role in the last phase of development when the retina reaches maturation. The presence of N1-acetylspermidine already at the 8th day indicates that in chick embryo retina, putrescine synthesis can depend on two separate pathways. The first involves ornithine decarboxylase activity; the second, spermidine/spermine N1-acetyltransferase an…

Regenerative Capacity of Adipose Derived Stem Cells (ADSCs), Comparison with Mesenchymal Stem Cells (MSCs).

2019

Adipose tissue is now on the top one of stem cell sources regarding its accessibility, abundance, and less painful collection procedure when compared to other sources. The adipose derived stem cells (ADSCs) that it contains can be maintained and expanded in culture for long periods of time without losing their differentiation capacity, leading to large cell quantities being increasingly used in cell therapy purposes. Many reports showed that ADSCs-based cell therapy products demonstrated optimal efficacy and efficiency in some clinical indications for both autologous and allogeneic purposes, hence becoming considered as potential tools for replacing, repairing, and regenerating dead or dama…

Synergistic effects of neurons and astrocytes on the differentiation of brain capillary endothelial cells in culture

2003

Brain capillary endothelial cells form a functional barrier between blood and brain, based on the existence of tight junctions that limit paracellular permeability. Occludin is one of the major transmembrane proteins of tight junctions and its peripheral localization gives indication of tight junction formation. We previously reported that RBE4.B cells (brain capillary endothelial cells), cultured on collagen IV, synthesize occludin and correctly localize it at the cell periphery only when cocultured with neurons. In the present study, we describe a three-cell type-culture system that allowed us to analyze the combined effects of neurons and astrocytes on differentiation of brain capillary …

RNA binding proteins in brain cells differentiation

2014

QUALITY COMPETITIVENESS OF LATVIA’S WOOD INDUSTRY

2012

Quality is a complex phenomenon and there exist no general accepted definition, which fits every purpose and all the complexities in teal economics. While competitiveness of enterprises has been studied by many scholars around the world, competitiveness of nations is a relatively new discipline. Studies of export competitiveness in the world markets are not new. Several attempts to evaluate export competitiveness have been made in the past, primarily in Eastern Europe. In Czechoslovakia, for example, a detailed and comprehensive analysis of the study was undertaken already in the 1960’s. Similar approach was used by World Bank studies of the price and quality competitiveness of exports by o…

Multifibrillar bundles of a self-assembling hyaluronic acid derivative obtained through a microfluidic technique for aortic smooth muscle cell orient…

2018

A hyaluronic acid derivative that is able to physically crosslink in a saline aqueous environment was employed for the production of fibers with a mean diameter of 50 μm using a microfluidic technique. The microfibers were collected in a tailored rotating collector and assembled to form multifibrillar bundles. The orientation of the microfibers on the collected bundles was evaluated by microCT analysis. The bundles were biofunctionalized by physical addition of fibronectin or chemical tethering of a cyRGDC peptide to achieve control of Aortic Smooth Muscle Cell (AoSMC) attachment, elongation and alignment. The mechanical performances of these bundles were evaluated by elongation tests, rela…