Direct and Indirect Biomimetic Peptide Modification of Alginate: Efficiency, Side Reactions, and Cell Response

In the fast-developing field of tissue engineering there is a constant demand for new materials as scaffolds for cell seeding, which can better mimic a natural extracellular matrix as well as control cell behavior. Among other materials, polysaccharides are widely used for this purpose. One of the main candidates for scaffold fabrication is alginate. However, it lacks sites for cell adhesion. That is why one of the steps toward the development of suitable scaffolds for cells is the introduction of the biofunctionality to the alginate structure. In this work we focused on bone-sialoprotein derived peptide (TYRAY) conjugation to the molecule of alginate. Here the comparison study on four different approaches of peptide conjugation was performed including traditional and novel modification methods, based on 1-Ethyl-3-(3-dimethylaminopropyl)carbodiimide/N-hydroxy succinimide (EDC/NHS), 4-(4,6-dimethoxy-1,3,5-triazine-2-yl)-4-methylmorpholinium chloride (DMTMM), thiol-Michael addition and Cu-catalyzed azide–alkyne cycloaddition reactions. It was shown that the combination of the alginate amidation with the use of and subsequent Cu-catalyzed azide–alkyne cycloaddition led to efficient peptide conjugation, which was proven with both NMR and XPS methods. Moreover, the cell culture experiment proved the positive effect of peptide presence on the adhesion of human embryonic stem cells.

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Super Enhancer Profiles Identify Key Cell Identity Genes During Differentiation From Embryonic Stem Cells to Trophoblast Stem Cells Super Enhencers in Trophoblast Differentiation

Frontiers in Genetics ◽

10.3389/fgene.2021.762529 ◽

2021 ◽

Vol 12 ◽

Author(s):

Rongpu Jia ◽

Yu Gao ◽

Song Guo ◽

Si Li ◽

Liangji Zhou ◽

...

Keyword(s):

Stem Cells ◽

Embryo Implantation ◽

Control Cell ◽

Embryonic Stem ◽

Growth Factor Receptor ◽

Chromatin Accessibility ◽

Integrated Analysis ◽

Cell Identity ◽

Trophoblast Stem Cells ◽

Trophoblast Stem

Trophoblast stem cells (TSCs) are derived from blastocysts and the extra-embryonic ectoderm (ExE) of post-implantation embryos and play a significant role in fetal development, but the roles that TSCs play in the earlier status of fetal diseases need further exploration. Super enhancers (SEs) are dense clusters of stitched enhancers that control cell identity determination and disease development and may participate in TSC differentiation. We identified key cell identity genes regulated by TSC-SEs via integrated analysis of H3K27ac and H3K4me1 chromatin immunoprecipitation sequencing (ChIP-seq), RNA-sequencing (RNA-seq) and ATAC-sequencing (ATAC-seq) data. The identified key TSC identity genes regulated by SEs, such as epidermal growth factor receptor (EGFR), integrin β5 (ITGB5) and Paxillin (Pxn), were significantly upregulated during TSC differentiation, and the transcription network mediated by TSC-SEs enriched in terms like focal adhesion and actin cytoskeleton regulation related to differentiation of TSCs. Additionally, the increased chromatin accessibility of the key cell identity genes verified by ATAC-seq further demonstrated the regulatory effect of TSC-SEs on TSC lineage commitment. Our results illustrated the significant roles of the TSC-SE-regulated network in TSC differentiation, and identified key TSC identity genes EGFR, ITGB5 and Pxn, providing novel insight into TSC differentiation and lays the foundation for future studies on embryo implantation and related diseases.

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Alignment of Carbon Nanotubes: An Approach to Modulate Cell Orientation and Asymmetry

Nano LIFE ◽

10.1142/s1793984414500020 ◽

2014 ◽

Vol 04 (01) ◽

pp. 1450002 ◽

Cited By ~ 1

Author(s):

Qingsu Cheng ◽

Greg M. Harris ◽

Marc-Olivier Blais ◽

Katy Rutledge ◽

Ehsan Jabbarzadeh

Keyword(s):

Stem Cells ◽

Control Cell ◽

Adhesion Formation ◽

Embryonic Stem ◽

Focal Adhesions ◽

Biological Tissues ◽

Spatiotemporal Pattern ◽

Cell Alignment ◽

Cell Orientation

Stem cells offer a promising tool in tissue engineering strategies, as their differentiated derivatives can be used to reconstruct most biological tissues. These approaches rely on controlling the biophysical cues that tune the ultimate fate of cells. In this context, significant effort has gone to parse out the role of conflicting matrix-elicited signals (e.g., topography and elasticity) in regulation of macroscopic characteristics of cells (e.g., shape and polarity). A critical hurdle, however, lies in our inability to recapitulate the nanoscale spatiotemporal pattern of these signals. The study presented in this manuscript took an initial step to overcome this challenge by developing a carbon nanotube (CNT)-based substrate for nanoresolution control of focal adhesion formation and cell alignment. The utility of this system was studied using human umbilical vascular endothelial cells (HUVECs) and human embryonic stem cells (hESCs) at a single cell level. Our results demonstrated the ability to control cell orientation by merely controlling the alignment of focal adhesions at a nanoscale size. Our long-term vision is to use these nanoengineered substrates to mimic cell orientation in earlier development and explore the role of polarity in asymmetric division and lineage specification of dividing cells.

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Controlling fluid flow to improve cell seeding uniformity

10.1101/299966 ◽

2018 ◽

Author(s):

Paul M. Reynolds ◽

Camilla Holzmann Rasmussen ◽

Mathias Hansson ◽

Martin Dufva ◽

Mathis O. Riehle ◽

...

Keyword(s):

Cell Density ◽

Embryonic Stem ◽

Local Variation ◽

Seeding Density ◽

Cell Seeding ◽

Simple Method ◽

Precise Control ◽

Seeding Method ◽

Macro Scale ◽

The Impact

AbstractStandard methods for seeding monolayer cell cultures in a multiwell plate or dish do not uniformly distribute cells on the surface. With traditional methods, users find aggregation around the circumference, in the centre, or a combination of the two. This variation is introduced due to the macro scale flow of the cell seeding suspension, and movement of the dish before cells can settle and attach to the surface. Reproducibility between labs, users, and experiments is hampered by this variability in cell seeding. We present a simple method for uniform and user-independent cell seeding using an easily produced uniform cell seeder (UCS) device. This allows precise control of cell density in a reproducible manner. By containing the cell seeding suspension in a defined volume above the culture surface with the UCS, fluctuations in cell density are minimised. Seeding accuracy, as defined by the actual cell density versus the target seeding density is improved dramatically across users with various levels of expertise. We go on to demonstrate the impact of local variation in cell density on the lineage commitment of human embryonic stem cells (hESCs) towards pancreatic endoderm (PE). Variations in the differentiation profile of cells across a culture well closely mirror variations in cell density introduced by seeding method – with the UCS correcting variations in differentiation efficiency. The UCS device provides a simple and reproducible method for uniform seeding across multiple culture systems.

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Food Design and Film Art in the Preservation of Ethnic Culture

Ethnic Culture ◽

10.31483/r-74950 ◽

2020 ◽

pp. 20-23

Author(s):

Valeri Ignatevich Kukenkov

Keyword(s):

Best Practices ◽

New Materials ◽

Ethnic Culture ◽

Historical Evidence ◽

Theoretical Justification ◽

Information Tools ◽

Folk Traditions ◽

Unusual Combination ◽

Food Design ◽

Positive Effect

The author outlines that the study of food design and film art as part of the country's ethnic culture examines the preservation and development of traditions and interethnic ties. Given that folk traditions have a peculiarity to develop, being in constant search of new solutions, taking into account the emergence of new materials, technologies and information tools, an idea to combine the potential of film art and food design in research has started up. It is noted that the search for analogues of the issue studied has no positive effect. The purpose of the study is a theoretical justification for the possibility of using different art forms as tools to unlock the possibilities and diversity of the art of food and filmmaking. Based on the study of various sources, it has been found that the topic of preserving the ethnic cultures of Russia is relevant and new, due to the unusual combination of the art of food and filmmaking. Hypothesis. It is suggested that the preservation and development of the country's ethnic cultures and intercultural ties is possible if best practices and achievements of food design as an essential part of people's culture will be applied while modelling different forms and spaces in film art. Results. Based on the results of the study, it can be concluded that the hypothesis put forward has historical evidence in the works of such scientists as: Kostomarov N.I., Orlovskaya A.V. and Pokhlebkin V.V. Based on their experience and knowledge the following is possible: formation of new approaches, serch for new solutions and development of new forms and spaces, using advances in food design, film art and people's culture.

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Constitutive Expression of GATA4 Dramatically Increases the Cardiogenic Potential of D3 Mouse Embryonic Stem Cells

The Open Biotechnology Journal ◽

10.2174/1874070701610010248 ◽

2016 ◽

Vol 10 (1) ◽

pp. 248-257 ◽

Cited By ~ 2

Author(s):

Lillian L. Laemmle ◽

Justus B. Cohen ◽

Joseph C. Glorioso

Keyword(s):

Cell Line ◽

Control Cell ◽

Embryonic Stem Cell Line ◽

Embryonic Stem ◽

Constitutive Expression ◽

Mouse Embryonic Stem Cell ◽

Embryoid Bodies ◽

Cardiomyocyte Differentiation ◽

Differentiated Cells ◽

Cardiac Gene

The transcription factor GATA binding protein 4 (GATA4) is a vital regulator of cardiac programming that acts by inducing the expression of many different genes involved in cardiomyogenesis. Here we generated a D3 mouse embryonic stem cell line that constitutively expresses high levels of GATA4 and show that these cells have dramatically increased cardiogenic potential compared to an eGFP-expressing control cell line. Embryoid bodies (EB) derived from the D3-GATA4 line displayed increased levels of cardiac gene expression and showed more abundant cardiomyocyte differentiation than control eGFP EB. These cells and two additional lines expressing lower levels of GATA4 provide a platform to screen previously untested cardiac genes and gene combinations for their ability to further increase the efficiency of cardiomyocyte differentiation beyond that achieved by transgenic GATA4 alone. Non-integrative delivery of identified gene combinations will aid in the production of differentiated cells for the treatment of ischemic cardiomyopathy.

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Evolutionarily Conserved Role of Nucleostemin: Controlling Proliferation of Stem/Progenitor Cells during Early Vertebrate Development

Molecular and Cellular Biology ◽

10.1128/mcb.01183-06 ◽

2006 ◽

Vol 26 (24) ◽

pp. 9291-9301 ◽

Cited By ~ 73

Author(s):

Chantal Beekman ◽

Massimo Nichane ◽

Sarah De Clercq ◽

Marion Maetens ◽

Thomas Floss ◽

...

Keyword(s):

Stem Cells ◽

Cell Proliferation ◽

Embryonic Stem Cells ◽

Progenitor Cells ◽

Control Cell ◽

Embryonic Stem ◽

Physiological Role ◽

Specific Gene

ABSTRACT Nucleostemin (NS) is a putative GTPase expressed preferentially in the nucleoli of neuronal and embryonic stem cells and several cancer cell lines. Transfection and knockdown studies indicated that NS controls the proliferation of these cells by interacting with the p53 tumor suppressor protein and regulating its activity. To assess the physiological role of NS in vivo, we generated a mutant mouse line with a specific gene trap event that inactivates the NS allele. The corresponding NS −/− embryos died around embryonic day 4. Analyses of NS mutant blastocysts indicated that NS is not required to maintain pluripotency, nucleolar integrity, or survival of the embryonic stem cells. However, the homozygous mutant blastocysts failed to enter S phase even in the absence of functional p53. Haploid insufficiency of NS in mouse embryonic fibroblasts leads to decreased cell proliferation. NS also functions in early amphibian development to control cell proliferation of neural progenitor cells. Our results show that NS has a unique ability, derived from an ancestral function, to control the proliferation rate of stem/progenitor cells in vivo independently of p53.

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Increasing the productivity and preservation of pigs by remedies of natural origin

BIO Web of Conferences ◽

10.1051/bioconf/20213204001 ◽

2021 ◽

Vol 32 ◽

pp. 04001

Author(s):

Antonina Dedkova ◽

Natalia Sergeyeva

Keyword(s):

Medicinal Plants ◽

Live Weight ◽

The Body ◽

Side Reactions ◽

Nonspecific Resistance ◽

Weaning Stress ◽

Natural Remedies ◽

As Stress ◽

Herbal Infusions ◽

Positive Effect

Research materials on the use of herbal infusions for the correction of weaning stress in piglets, as well as the complex use of natural products as stress correctors are presented in the article. Infusions of medicinal plants from the leaves of nettle, plantain, rose hips and rowan were used to normalize metabolism and increase the overall immunological resistance of the body. They are distinguished by good tolerance, very rare development of negative side reactions, even with prolonged use. It has been experimentally established that the adaptogenic effect of infusions of nettle, plantain, wild rose and rowan is manifested by an increase in the general nonspecific resistance of the animal body due to the effect on the stress-limiting systems of the body. As a result of the studies carried out, it was found that the use of medicinal plants had a positive effect on the use of feed nutrients by animals and a change in the live weight of pigs. The complex use of natural remedies contributed to an increase in the growth rate of young animals and, ultimately, to an increase in their preservation and productivity. The use of rose hip infusions 20 days before weaning of piglets from sows turned out to be the most effective in terms of preservation, growth and additional income when growing piglets.

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Characterisation of interactions between the pluripotency transcription factors Nanog, Oct4 and Sox2

10.1101/2020.06.24.169185 ◽

2020 ◽

Author(s):

Tapan Kumar Mistri ◽

David Kelly ◽

John Mak ◽

Douglas Colby ◽

Nicholas Mullin ◽

...

Keyword(s):

Transcription Factors ◽

Gene Regulatory Network ◽

Single Molecule ◽

Regulatory Network ◽

Es Cells ◽

Control Cell ◽

Embryonic Stem ◽

Correlation Spectroscopy ◽

Dependent Manner ◽

Gene Regulatory

ABSTRACTThe pluripotency transcription factors (TFs) Nanog, Sox2, and Oct4 are at the centre of the gene regulatory network that controls cell identity in embryonic stem (ES) cells. However, the mechanisms by which these factors control cell fate, and their interactions with one another are not fully understood. Here we combine biophysical and novel biochemical assays to assess how these factors interact with each other quantitatively. A new confocal microscopy method to detect binding of a target protein to a fluorescently labelled partner (coimmunoprecipitation bead imaging microscopy [CBIM]) is presented and used to demonstrate homotypic binding of Nanog and heterotypic binding between Nanog and Sox2 and between Nanog and Oct4. Using fluorescence correlation spectroscopy we show that in solution, Nanog but not Oct4 or Sox2 can form homodimers. Fluorescence Cross Correlation Spectroscopy shows that the affinity of Nanog for dimer formation is in the order Sox2 > Nanog > Oct4. Importantly, live cell analysis demonstrate the existence of Nanog homodimers in vivo. While Sox2 and Oct4 bind one another in a DNA-dependent manner, Nanog appears not to bridge Sox2 and Oct4, even though Nanog binds both Sox2 and Oct4 individually. Together these findings extend understanding of the molecular interactions occurring between these central mediators of the pluripotency gene regulatory network at the single molecule level.

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Core transcriptional regulatory circuitries in cancer

Oncogene ◽

10.1038/s41388-020-01459-w ◽

2020 ◽

Vol 39 (43) ◽

pp. 6633-6646 ◽

Cited By ~ 1

Author(s):

Ye Chen ◽

Liang Xu ◽

Ruby Yu-Tong Lin ◽

Markus Müschen ◽

H. Phillip Koeffler

Keyword(s):

Gene Expression ◽

Control Cell ◽

Embryonic Stem ◽

Cell Types ◽

Specific Gene ◽

Cancer Knowledge ◽

Fashion Studies ◽

Transcriptional Regulatory ◽

Cell Type Specific ◽

Expression Program

Abstract Transcription factors (TFs) coordinate the on-and-off states of gene expression typically in a combinatorial fashion. Studies from embryonic stem cells and other cell types have revealed that a clique of self-regulated core TFs control cell identity and cell state. These core TFs form interconnected feed-forward transcriptional loops to establish and reinforce the cell-type-specific gene-expression program; the ensemble of core TFs and their regulatory loops constitutes core transcriptional regulatory circuitry (CRC). Here, we summarize recent progress in computational reconstitution and biologic exploration of CRCs across various human malignancies, and consolidate the strategy and methodology for CRC discovery. We also discuss the genetic basis and therapeutic vulnerability of CRC, and highlight new frontiers and future efforts for the study of CRC in cancer. Knowledge of CRC in cancer is fundamental to understanding cancer-specific transcriptional addiction, and should provide important insight to both pathobiology and therapeutics.

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