scholarly journals Parallelized Manipulation of Adherent Living Cells by Magnetic Nanoparticles-Mediated Forces

2020 ◽  
Vol 21 (18) ◽  
pp. 6560 ◽  
Author(s):  
Maud Bongaerts ◽  
Koceila Aizel ◽  
Emilie Secret ◽  
Audric Jan ◽  
Tasmin Nahar ◽  
...  
Keyword(s):  
Cell Migration ◽  
Magnetic Nanoparticles ◽  
Neurite Outgrowth ◽  
Live Cell Imaging ◽  
Adherent Cell ◽  
Cell Periphery ◽  
Biological Processes ◽  
Cellular Processes ◽  
Neuronal Outgrowth ◽  
Pulling Force

The remote actuation of cellular processes such as migration or neuronal outgrowth is a challenge for future therapeutic applications in regenerative medicine. Among the different methods that have been proposed, the use of magnetic nanoparticles appears to be promising, since magnetic fields can act at a distance without interactions with the surrounding biological system. To control biological processes at a subcellular spatial resolution, magnetic nanoparticles can be used either to induce biochemical reactions locally or to apply forces on different elements of the cell. Here, we show that cell migration and neurite outgrowth can be directed by the forces produced by a switchable parallelized array of micro-magnetic pillars, following the passive uptake of nanoparticles. Using live cell imaging, we first demonstrate that adherent cell migration can be biased toward magnetic pillars and that cells can be reversibly trapped onto these pillars. Second, using differentiated neuronal cells we were able to induce events of neurite outgrowth in the direction of the pillars without impending cell viability. Our results show that the range of forces applied needs to be adapted precisely to the cellular process under consideration. We propose that cellular actuation is the result of the force on the plasma membrane caused by magnetically filled endo-compartments, which exert a pulling force on the cell periphery.

scholarly journals Parallelized manipulation of adherent living cells by magnetic nanoparticles-mediated forces

2020 ◽  
Author(s):  
Maud Bongaerts ◽  
Koceila Aizel ◽  
Emilie Secret ◽  
Jan Audric ◽  
Tasmin Nahar ◽  
...  
Keyword(s):  
Cell Migration ◽  
Magnetic Nanoparticles ◽  
Neurite Outgrowth ◽  
Live Cell Imaging ◽  
Adherent Cell ◽  
Cell Periphery ◽  
Biological Processes ◽  
Cellular Processes ◽  
Neuronal Outgrowth ◽  
Pulling Force

AbstractThe remote actuation of cellular processes such as migration or neuronal outgrowth is a challenge for future therapeutic applications in regenerative medicine. Among the different methods that have been proposed, the use of magnetic nanoparticles appears to be promising since magnetic fields can act at a distance without interactions with the surrounding biological system. To control biological processes at a subcellular spatial resolution, magnetic nanoparticles can be used either to induce biochemical reactions locally or to apply forces on different elements of the cell. Here, we show that cell migration and neurite outgrowth can be directed by the forces produced by a switchable parallelized array of micro-magnetic pillars, following passive uptake of nanoparticles. Using live cell imaging, we first demonstrate that adherent cell migration can be biased toward magnetic pillars and that cells can be reversibly trapped onto these pillars. Second, using differentiated neuronal cells we were able to induce events of neurite outgrowth in the direction of the pillars without impending cell viability. Our results show that the range of forces applied needs to be adapted precisely to the cellular process under consideration. We propose that cellular actuation is the result of the force on the plasma membrane caused by magnetically filled endo-compartments, which exert a pulling force on the cell periphery.

scholarly journals Archaeal imaging: leading the hunt for new discoveries

2018 ◽  
Vol 29 (14) ◽  
pp. 1675-1681 ◽  
Author(s):  
Alexandre W. Bisson-Filho ◽  
Jenny Zheng ◽  
Ethan Garner
Keyword(s):  
Live Cell Imaging ◽  
Cell Imaging ◽  
Structural Information ◽  
Eukaryotic Cell ◽  
Live Cell ◽  
Biological Processes ◽  
Cellular Processes ◽  
Archaeal Species ◽  
Eukaryotic Organisms ◽  
Cellular Components

Since the identification of the archaeal domain in the mid-1970s, we have collected a great deal of metagenomic, biochemical, and structural information from archaeal species. However, there is still little known about how archaeal cells organize their internal cellular components in space and time. In contrast, live-cell imaging has allowed bacterial and eukaryotic cell biologists to learn a lot about biological processes by observing the motions of cells, the dynamics of their internal organelles, and even the motions of single molecules. The explosion of knowledge gained via live-cell imaging in prokaryotes and eukaryotes has motivated an ever-improving set of imaging technologies that could allow analogous explorations into archaeal biology. Furthermore, previous studies of essential biological processes in prokaryotic and eukaryotic organisms give methodological roadmaps for the investigation of similar processes in archaea. In this perspective, we highlight a few fundamental cellular processes in archaea, reviewing our current state of understanding about each, and compare how imaging approaches helped to advance the study of similar processes in bacteria and eukaryotes.

scholarly journals cNap1 bridges centriole contact sites to maintain centrosome cohesion

2021 ◽  
Author(s):  
Robert Mahen
Keyword(s):  
Cell Migration ◽  
Live Cell Imaging ◽  
Cell Imaging ◽  
Spatial Proximity ◽  
Contact Site ◽  
Physical Force ◽  
Cellular Processes ◽  
Contact Sites ◽  
Reduced Viscosity ◽  
Membrane Bound

Centrioles are non-membrane bound organelles that participate in fundamental cellular processes through their ability to form physical contacts with other structures. During interphase, two mature centrioles can associate to form a single centrosome - a phenomenon known as centrosome cohesion. Centrosome cohesion is important for processes such as cell migration, and yet how it is maintained is unclear. Current models indicate that pericentriolar fibres termed rootlets, also known as the centrosome linker, entangle to maintain centriole proximity. Here, I uncover a new centriole-centriole contact site and mechanism of centrosome cohesion, based on coalescence of the proximal centriole component cNap1. Using live-cell imaging of endogenously tagged cNap1, I show that proximal centrioles form dynamic contacts in response to physical force from the cytoskeleton. Expansion microscopy reveals that cNap1 bridges between these contact sites, physically linking proximal centrioles on the nanoscale. When ectopically tethered to organelles such as lysosomes, cNap1 forms viscous and cohesive condensates that promote organelle spatial proximity. Conversely, cNap1 mutants with reduced viscosity are unable to maintain centrosome cohesion. These results define a previously unrecognised mechanism of centrosome cohesion by cNap1 assemblies at the proximal centriole and illustrate how a non-membrane bound organelle forms dynamic organelle contact sites.

scholarly journals Regulation of Rho GTPases by RhoGDIs in Human Cancers

Cells ◽  
2019 ◽  
Vol 8 (9) ◽  
pp. 1037 ◽  
Author(s):  
Cho ◽  
Kim ◽  
Baek ◽  
Kim ◽  
Lee
Keyword(s):  
Cell Migration ◽  
Cancer Progression ◽  
Anticancer Agents ◽  
Rho Gtpases ◽  
Rho Gtpase ◽  
Regulatory Mechanisms ◽  
Malignant Phenotype ◽  
Cellular Processes ◽  
Human Cancers

Rho GDP dissociation inhibitors (RhoGDIs) play important roles in various cellular processes, including cell migration, adhesion, and proliferation, by regulating the functions of the Rho GTPase family. Dissociation of Rho GTPases from RhoGDIs is necessary for their spatiotemporal activation and is dynamically regulated by several mechanisms, such as phosphorylation, sumoylation, and protein interaction. The expression of RhoGDIs has changed in many human cancers and become associated with the malignant phenotype, including migration, invasion, metastasis, and resistance to anticancer agents. Here, we review how RhoGDIs control the function of Rho GTPases by regulating their spatiotemporal activity and describe the regulatory mechanisms of the dissociation of Rho GTPases from RhoGDIs. We also discuss the role of RhoGDIs in cancer progression and their potential uses for therapeutic intervention.

Study of NSCLC cell migration promoted by NSCLC-Derived Extracellular Vesicle using atomic force microscopy

2021 ◽  
Author(s):  
Shuwei Wang ◽  
Jiajia Wang ◽  
Tuoyu Ju ◽  
Kaige Qu ◽  
Fan Yang ◽  
...  
Keyword(s):  
Atomic Force Microscopy ◽  
Cell Migration ◽  
Cancer Cells ◽  
Extracellular Vesicles ◽  
Extracellular Vesicle ◽  
Cancer Microenvironment ◽  
Biological Processes ◽  
Force Microscopy ◽  
Atomic Force ◽  
Cellular Components

Extracellular Vesicles (EVs) secreted by cancer cells have a key role in the cancer microenvironment and progression. Previous studies have mainly focused on molecular functions, cellular components and biological processes...

scholarly journals Intrinsically Disordered Proteins as Regulators of Transient Biological Processes and as Untapped Drug Targets

Molecules ◽  
2021 ◽  
Vol 26 (8) ◽  
pp. 2118
Author(s):  
Yusuke Hosoya ◽  
Junko Ohkanda
Keyword(s):  
Drug Targets ◽  
Intrinsically Disordered Proteins ◽  
Dynamic Control ◽  
Disordered Proteins ◽  
Biological Processes ◽  
Phase Separations ◽  
Cellular Processes ◽  
Intrinsically Disordered ◽  
New Drug ◽  
Liquid Phase Separations

Intrinsically disordered proteins (IDPs) are critical players in the dynamic control of diverse cellular processes, and provide potential new drug targets because their dysregulation is closely related to many diseases. This review focuses on several medicinal studies that have identified low-molecular-weight inhibitors of IDPs. In addition, clinically relevant liquid–liquid phase separations—which critically involve both intermolecular interactions between IDPs and their posttranslational modification—are analyzed to understand the potential of IDPs as new drug targets.

scholarly journals Developmental Neurotoxicity of Fipronil and Rotenone on a Human Neuronal In Vitro Test System

2021 ◽  
Author(s):  
Anne Schmitz ◽  
Silke Dempewolf ◽  
Saime Tan ◽  
Gerd Bicker ◽  
Michael Stern
Keyword(s):  
Cell Migration ◽  
Neurite Outgrowth ◽  
Neuronal Differentiation ◽  
Precursor Cell ◽  
Developmental Neurotoxicity ◽  
In Vitro Studies ◽  
Human Model ◽  
In Vitro Test ◽  
Dependent Manner

AbstractPesticide exposure during in utero and early postnatal development can cause a wide range of neurological defects. However, relatively few insecticides have been recognized as developmental neurotoxicants, so far. Recently, discovery of the insecticide, fipronil, in chicken eggs has raised public concern. The status of fipronil as a potential developmental neurotoxicant is still under debate. Whereas several in vivo and in vitro studies suggest specific toxicity, other in vitro studies could not confirm this concern. Here, we tested fipronil and its main metabolic product, fipronil sulfone both at concentrations between 1.98 and 62.5 µM, alongside with the established developmental neurotoxicant, rotenone (0.004–10 µM) in vitro on the human neuronal precursor cell line NT2. We found that rotenone impaired all three tested DNT endpoints, neurite outgrowth, neuronal differentiation, and precursor cell migration in a dose-dependent manner and clearly separable from general cytotoxicity in the nanomolar range. Fipronil and fipronil sulfone specifically inhibited cell migration and neuronal differentiation, but not neurite outgrowth in the micromolar range. The rho-kinase inhibitor Y-27632 counteracted inhibition of migration for all three compounds (EC50 between 12 and 50 µM). The antioxidant, n-acetyl cysteine, could ameliorate the inhibitory effects of fipronil on all three tested endpoints (EC 50 between 84 and 164 µM), indicating the involvement of oxidative stress. Fipronil sulfone had a stronger effect than fipronil, confirming the importance to test metabolic products alongside original pesticides. We conclude that in vitro fipronil and fipronil sulfone display specific developmental neurotoxicity on developing human model neurons.

scholarly journals Tracking changes in adaptation to suspension growth for MDCK cells: cell growth correlates with levels of metabolites, enzymes and proteins

2021 ◽  
Vol 105 (5) ◽  
pp. 1861-1874
Author(s):  
Sabine Pech ◽  
Markus Rehberg ◽  
Robert Janke ◽  
Dirk Benndorf ◽  
Yvonne Genzel ◽  
...  
Keyword(s):  
Cell Growth ◽  
Cell Line ◽  
Mdck Cells ◽  
Suspension Cell ◽  
Regulatory Mechanisms ◽  
Adherent Cell ◽  
Holistic View ◽  
Cellular Processes ◽  
Viral Vaccine ◽  
Analytical Approaches

Abstract Adaptations of animal cells to growth in suspension culture concern in particular viral vaccine production, where very specific aspects of virus-host cell interaction need to be taken into account to achieve high cell specific yields and overall process productivity. So far, the complexity of alterations on the metabolism, enzyme, and proteome level required for adaptation is only poorly understood. In this study, for the first time, we combined several complex analytical approaches with the aim to track cellular changes on different levels and to unravel interconnections and correlations. Therefore, a Madin-Darby canine kidney (MDCK) suspension cell line, adapted earlier to growth in suspension, was cultivated in a 1-L bioreactor. Cell concentrations and cell volumes, extracellular metabolite concentrations, and intracellular enzyme activities were determined. The experimental data set was used as the input for a segregated growth model that was already applied to describe the growth dynamics of the parental adherent cell line. In addition, the cellular proteome was analyzed by liquid chromatography coupled to tandem mass spectrometry using a label-free protein quantification method to unravel altered cellular processes for the suspension and the adherent cell line. Four regulatory mechanisms were identified as a response of the adaptation of adherent MDCK cells to growth in suspension. These regulatory mechanisms were linked to the proteins caveolin, cadherin-1, and pirin. Combining cell, metabolite, enzyme, and protein measurements with mathematical modeling generated a more holistic view on cellular processes involved in the adaptation of an adherent cell line to suspension growth. Key points • Less and more efficient glucose utilization for suspension cell growth • Concerted alteration of metabolic enzyme activity and protein expression • Protein candidates to interfere glycolytic activity in MDCK cells

Ras induces NBT-II epithelial cell scattering through the coordinate activities of Rac and MAPK pathways

2002 ◽  
Vol 115 (12) ◽  
pp. 2591-2601 ◽  
Author(s):  
Natacha Edme ◽  
Julian Downward ◽  
Jean-Paul Thiery ◽  
Brigitte Boyer
Keyword(s):  
Cell Migration ◽  
Cell Motility ◽  
Mapk Pathway ◽  
Small Gtpase ◽  
Dominant Negative Mutant ◽  
Cell Periphery ◽  
Cell Dissociation ◽  
Downstream Targets ◽  
Cell Dispersion ◽  
Cell Scattering

Cell dissociation and cell migration are the two main components of epithelium-mesenchyme transitions (EMT). We previously demonstrated that Ras is required for the accomplishment of both of these processes during the EGF-induced EMT of the NBT-II rat carcinoma cell line in vitro. In this study,we examined the downstream targets of Ras that are responsible for the dissociation and motility of NBT-II cells. Overexpression of activated forms of c-Raf and MEK1 (a component of the mitogen-activated protein kinase pathway, MAPK) led to cell dissociation, as inferred by the loss of desmosomes from the cell periphery. By contrast, active PI3K, RalA and RalB did not induce desmosome breakdown. The MEK1 inhibitor PD098059 inhibited EGF- and Ras-induced cell dispersion, whereas the PI3K inhibitor LY294002 had no effect. Accordingly, among the partial loss-of-function mutants of Ras(RasV12) that were used to distinguish between downstream targets of Ras, we found that the Raf-specific Ras mutants RasV12S35 and RasV12E38 induced cell dissociation. The PI3K- and RalGDS-activating Ras mutants had, in contrast, no effect on cell dispersion. However, MEK1 was unable to promote cell motility,whereas RasV12S35 and RasV12E38 induced cell migration, suggesting that another Ras effector was responsible for cell motility. We found that the small GTPase Rac is necessary for EGF-mediated cell dispersion since overexpression of a dominant-negative mutant of Rac1 (Rac1N17) inhibited EGF-induced NBT-II cell migration. All stimuli that promoted cell migration also induced Rac activation. Finally, coexpression of active Rac1 and active MEK1 induced the motility of NBT-II cells, suggesting that Ras mediates NBT-II cell scattering through the coordinate activation of Rac and the Raf/MAPK pathway.

Plasticity in designing PROTACs for selective and potent degradation of HDAC6

2019 ◽  
Vol 55 (98) ◽  
pp. 14848-14851 ◽  
Author(s):  
Haiyan Yang ◽  
Wenxing Lv ◽  
Ming He ◽  
Haiteng Deng ◽  
Haitao Li ◽  
...  
Keyword(s):  
Cell Migration ◽  
Protein Degradation ◽  
Histone Deacetylase ◽  
Histone Deacetylase 6 ◽  
Cellular Processes

HDAC6 (histone deacetylase 6) catalyses the deacetylation of non-histone substrates, and plays important roles in cell migration, protein degradation and other cellular processes.

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