scholarly journals Geometric principles underlying the proliferation of a model cell system

2019 ◽  
Author(s):  
Ling Juan Wu ◽  
Seoungjun Lee ◽  
Sungshic Park ◽  
Lucy E. Eland ◽  
Anil Wipat ◽  
...  
Keyword(s):  
Dominant Role ◽  
Volume Effect ◽  
Cell System ◽  
Minimal Cell ◽  
Cell Functions ◽  
Model Cell ◽  
Linear Configuration ◽  
A Cell ◽  
Volume Cell ◽  
Geometric Effects

SUMMARYWall deficient variants of many bacteria, called L-forms, divide by a simple mechanism that does not depend on the complex FtsZ-based cell division machine. We have used microfluidic systems to probe the growth, chromosome cycle and division mechanism of Bacillus subtilis L-forms. The results show that forcing cells into a narrow linear configuration greatly improves the efficiency of cell growth and chromosome segregation. This reinforces the view that L-form division is driven by an excess accumulation of surface area over volume. Cell geometry was also found to play a dominant role in controlling the relative positions and movement of segregating chromosomes. The presence of the nucleoid appears to influence division both via a cell volume effect and by nucleoid occlusion, even in the absence of the FtsZ machine. Overall, our results emphasise the importance of geometric effects for a range of critical cell functions and are of relevance for efforts to develop artificial or minimal cell systems.

Proteomic Characterization of Protein-Protein Interactions

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Veenstra TD ◽  
Keyword(s):  
Protein Interactions ◽  
Disease Diagnosis ◽  
Cell System ◽  
Protein Protein Interactions ◽  
Novel Technologies ◽  
Cell Functions ◽  
Single Protein ◽  
A Cell ◽  
Molecular Components

Identifying all the molecular components within a living cell is the first step into understanding how it functions. To further understand how a cell functions requires identifying the interactions that occur between these components. This fact is especially relevant for proteins. No protein within a human cell functions on its own without interacting with another biomolecule - usually another protein. While Protein-Protein Interactions (PPI) have historically been determined by examining a single protein per study, novel technologies developed over the past couple of decades are enabling high-throughput methods that aim to describe entire protein networks within cells. In this review, some of the technologies that have led to these developments are described along with applications of these techniques. Ultimately the goal of these technologies is to map out the entire circuitry of PPI within human cells to be able to predict the global consequences of perturbations to the cell system. This predictive capability will have major impacts on the future of both disease diagnosis and treatment.

Spheroid organization kinetics of H35 rat hepatoma model cell system on elastin-like polypeptide-polyethyleneimine copolymer substrates

2013 ◽  
Vol 102 (3) ◽  
pp. 852-861 ◽  
Author(s):  
Paul A. Turner ◽  
C. Andrew Weeks ◽  
Austin J. McMurphy ◽  
Amol V. Janorkar
Keyword(s):  
Cell System ◽  
Model Cell ◽  
Kinetics Of ◽  
Hepatoma Model ◽  
Rat Hepatoma

scholarly journals Overcoming the Challenges for a Mass Manufacturing Machine for the Assembly of PEMFC Stacks

Machines ◽  
2019 ◽  
Vol 7 (4) ◽  
pp. 66 ◽  
Author(s):  
Porstmann ◽  
Wannemacher ◽  
Richter
Keyword(s):  
Fuel Cell ◽  
Economies Of Scale ◽  
Polymer Electrolyte Membrane ◽  
Cell System ◽  
Active Components ◽  
Fuel Cell Stack ◽  
Electrolyte Membrane ◽  
Modular Concept ◽  
A Cell ◽  
Manufacturing Machine

One of the major obstacles standing in the way of a break-through in fuel cell technology is its relatively high costs compared to well established fossil-based technologies. The reasons for these high costs predominantly lie in the use of non-standardized components, complex system components, and non-automated production of fuel cells. This problem can be identified at multiple levels, for example, the electrochemically active components of the fuel cell stack, peripheral components of the fuel cell system, and eventually on the level of stack and system assembly. This article focused on the industrialization of polymer electrolyte membrane fuel cell (PEMFC) stack components and assembly. To achieve this, the first step is the formulation of the requirement specifications for the automated PEMFC stack production. The developed mass manufacturing machine (MMM) enables a reduction of the assembly time of a cell fuel cell stack to 15 minutes. Furthermore the targeted automation level is theoretically capable of producing up to 10,000 fuel cell stacks per year. This will result in a ~50% stack cost reduction through economies of scale and increased automation. The modular concept is scalable to meet increasing future demand which is essential for the market ramp-up and success of this technology.

scholarly journals Neuroepithelial cell competition triggers loss of cellular juvenescence

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Faidruz Azura Jam ◽  
Takao Morimune ◽  
Atsushi Tsukamura ◽  
Ayami Tano ◽  
Yuya Tanaka ◽  
...  
Keyword(s):  
Interaction Mechanism ◽  
Cell Interaction ◽  
Neuroepithelial Cell ◽  
Cell Competition ◽  
Early Brain Development ◽  
Associated Proteins ◽  
Model Cell ◽  
A Cell ◽  
Model Expression

Abstract Cell competition is a cell–cell interaction mechanism which maintains tissue homeostasis through selective elimination of unfit cells. During early brain development, cells are eliminated through apoptosis. How cells are selected to undergo elimination remains unclear. Here we aimed to identify a role for cell competition in the elimination of suboptimal cells using an in vitro neuroepithelial model. Cell competition was observed when neural progenitor HypoE-N1 cells expressing RASV12 were surrounded by normal cells in the co-culture. The elimination through apoptosis was observed by cellular changes of RASV12 cells with rounding/fragmented morphology, by SYTOX blue-positivity, and by expression of apoptotic markers active caspase-3 and cleaved PARP. In this model, expression of juvenility-associated genes Srsf7 and Ezh2 were suppressed under cell-competitive conditions. Srsf7 depletion led to loss of cellular juvenescence characterized by suppression of Ezh2, cell growth impairment and enhancement of senescence-associated proteins. The cell bodies of eliminated cells were engulfed by the surrounding cells through phagocytosis. Our data indicates that neuroepithelial cell competition may have an important role for maintaining homeostasis in the neuroepithelium by eliminating suboptimal cells through loss of cellular juvenescence.

scholarly journals Formation of Water-Free Cavity in the Process of Nafion Swelling in a Cell of Limited Volume; Effect of Polymer Fibers Unwinding

Polymers ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 2888
Author(s):  
Barry W. Ninham ◽  
Polina N. Bolotskova ◽  
Sergey V. Gudkov ◽  
Yulchi Juraev ◽  
Mariya S. Kiryanova ◽  
...  
Keyword(s):  
Colloidal Particles ◽  
Temporal Dynamics ◽  
Polymer Surface ◽  
Volume Effect ◽  
Polymer Fibers ◽  
Exclusion Zone ◽  
Limited Volume ◽  
Water Pretreatment ◽  
A Cell ◽  
Cell Window

When Nafion swells in water, colloidal particles are repelled from the polymer surface; this effect is called the formation exclusion zone (EZ), and the EZ size amounts to several hundred microns. However, still no one has investigated the EZ formation in a cell whose dimension is close to the EZ size. It was also shown that, upon swelling in water, Nafion fibers “unwind” into the water bulk. In the case of a cell of limited volume, unwound fibers abut against the cell windows, and water is completely pushed out from the region between the polymer and the cell window, resulting in a cavity appearance. The temporal dynamics of the collapse of this cavity was studied depending on the cell size. It is shown that the cavity formation occurs due to long-range forces between polymer strands. It turned out that this scenario depends on the isotopic composition of the water, ionic additives and water pretreatment. The role of nanobubbles in the formation and collapse of the cavity were analyzed. The results obtained allowed us to conclude that the EZ formation is precisely due to the unwinding of polymer fibers into the liquid bulk.

scholarly journals Immunomodulatory role of phagocyte-derived chloramines involving lymphocyte glutathione

1993 ◽  
Vol 2 (3) ◽  
pp. 235-241 ◽  
Author(s):  
Véronique Witko-Sarsat ◽  
Anh Thu Nguyen ◽  
Béatrice Descamps-Latscha
Keyword(s):  
Oxidative Stress ◽  
Reduced Glutathione ◽  
Human Lymphocytes ◽  
Cell System ◽  
Polymorphonuclear Neutrophils ◽  
Myristate Acetate ◽  
Defensive Role ◽  
Free Model ◽  
A Cell

This study shows that human lymphocytes markedly decrease chloramines (long-lived oxidants) generated by polymorphonuclear neutrophils (PMN) after stimulation by phorbol-myristate-acetate or opsonized zymosan. In a cell-free model, reduced glutathione (GSH) scavenged chloramines, giving rise to oxidized glutathione (GSSG). In the cell system, treatment of lymphocytes with autologous PMN-derived chloramines induced a profound decrease in their total and reduced glutathione (GSH) content and markedly inhibited their proliferate responses to concanavalin-A and, to a lesser extent, phytohaemagglutinin. It is concluded that (i) lymphocytes may play a defensive role against phagocyte-derived oxidative stress by scavenging chloramines, and (ii) as this effect which is mediated by GSH affects lymphocyte proliferative responses, it may help to elucidate the still obscure mechanisms of oxidative stress associated immunodeficiency.

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