Faculty Opinions recommendation of Rho and F-actin self-organize within an artificial cell cortex.

2021 ◽  
Author(s):  
Ram Dixit
Keyword(s):  
Cell Cortex ◽  
Artificial Cell

scholarly journals Rho and F-actin self-organize within an artificial cell cortex

2021 ◽  
Author(s):  
Jennifer Landino ◽  
Marcin Leda ◽  
Ani Michaud ◽  
Zachary T. Swider ◽  
Mariah Prom ◽  
...  
Keyword(s):  
Cell Division ◽  
Rho Gtpase ◽  
Cortical Excitability ◽  
Cell Cortex ◽  
List Type ◽  
Actin Assembly ◽  
Cortical Dynamics ◽  
Artificial Cell ◽  
Egg Extract ◽  
Dynamic Patterns

SummaryThe cell cortex, comprised of the plasma membrane and underlying cytoskeleton, undergoes dynamic reorganizations during a variety of essential biological processes including cell adhesion, cell migration, and cell division1,2. During cell division and cell locomotion, for example, waves of filamentous-actin (F-actin) assembly and disassembly develop in the cell cortex in a process termed “cortical excitability”3–7. In developing frog and starfish embryos, cortical excitability is generated through coupled positive and negative feedback, with rapid activation of Rho-mediated F-actin assembly followed in space and time by F-actin-dependent inhibition of Rho8,9. These feedback loops are proposed to serve as a mechanism for amplification of active Rho signaling at the cell equator to support furrowing during cytokinesis, while also maintaining flexibility for rapid error correction in response to movement of the mitotic spindle during chromosome segregation10. In this paper, we develop an artificial cortex based on Xenopus egg extract and supported lipid bilayers (SLBs), to investigate cortical Rho and F-actin dynamics11. This reconstituted system spontaneously develops two distinct dynamic patterns: singular excitable Rho and F-actin waves and non-traveling oscillatory Rho and F-actin patches. Both types of dynamic patterns have properties and dependencies similar to the cortical excitability previously characterized in vivo9. These findings directly support the longstanding speculation that the cell cortex is a self-organizing structure and present a novel approach for investigating mechanisms of Rho-GTPase-mediated cortical dynamics.HighlightsAn artificial cell cortex comprising Xenopus egg extract on a supported lipid bilayer self-organizes into complex, dynamic patterns of active Rho and F-actinWe identified two types of reconstituted cortical dynamics – excitable waves and coherent oscillationsReconstituted waves and oscillations require Rho activity and F-actin polymerization

scholarly journals Rho and F-Actin Self-Organize within an Artificial Cell Cortex

2021 ◽  
Author(s):  
Jennifer Landino ◽  
Marcin Leda ◽  
Ani Michaud ◽  
Zachary Swider ◽  
Mariah Prom ◽  
...  
Keyword(s):  
Cell Cortex ◽  
Artificial Cell

Confocal microscopy of the cytoskeleton in living plant cells following microinjection of fluorescent probes

1993 ◽  
Vol 51 ◽  
pp. 130-131
Author(s):  
Ann Cleary
Keyword(s):  
Cell Division ◽  
Fluorescent Probes ◽  
Actin Filaments ◽  
Intracellular Transport ◽  
Cell Structure ◽  
Plant Cells ◽  
Cell Plate ◽  
Cell Cortex ◽  
Living Plant ◽  
Rhodamine Phalloidin

Microinjection of fluorescent probes into living plant cells reveals new aspects of cell structure and function. Microtubules and actin filaments are dynamic components of the cytoskeleton and are involved in cell growth, division and intracellular transport. To date, cytoskeletal probes used in microinjection studies have included rhodamine-phalloidin for labelling actin filaments and fluorescently labelled animal tubulin for incorporation into microtubules. From a recent study of Tradescantia stamen hair cells it appears that actin may have a role in defining the plane of cell division. Unlike microtubules, actin is present in the cell cortex and delimits the division site throughout mitosis. Herein, I shall describe actin, its arrangement and putative role in cell plate placement, in another material, living cells of Tradescantia leaf epidermis.The epidermis is peeled from the abaxial surface of young leaves usually without disruption to cytoplasmic streaming or cell division. The peel is stuck to the base of a well slide using 0.1% polyethylenimine and bathed in a solution of 1% mannitol +/− 1 mM probenecid.

Osmolarity and Artificial Cell Damage in Ischemic Myocardium

1990 ◽  
Vol 48 (3) ◽  
pp. 262-263
Author(s):  
Richard Montione ◽  
Muhammad Ashraf
Keyword(s):  
Cell Damage ◽  
Uranyl Acetate ◽  
Tissue Preservation ◽  
Rat Myocardium ◽  
En Bloc ◽  
Cellular Changes ◽  
Artificial Cell ◽  
Cacodylate Buffer ◽  
Isotonic Buffer ◽  
Perfusion Fixation

Osmolarity of a fixative vehicle has long been known to have an effect on the tissue preservation. An increase in tissue osmolarity occurs in ischemia-damaged tissue and affects the morphology. In this study, we examined cellular changes in ischemic rat myocardium induced by varying fixative toxicity.Rats were sacrificed by decapitation and the hearts immediately removed and retrogradily perfused through the aorta with anoxic Kurbs-Henseleit medium. Hearts were then placed in a bag with a small amount of medium at 37°C for 90 minutes. Hearts were perfusion-fixed using 2% glutaraldehyde in 0.1 M cacodylate buffer pH -7.3 at three osmolarities. The isotonic buffer was adjusted to 311 mOsm/kg using D-manitol. Hypertonic buffers were adjusted to 375 and 400 mOsm/kg. One-half hour after perfusion fixation, the hearts were sliced and cut into small blocks and allowed to fix overnight at 4°C. Blocks were post fixed in osmium, en bloc stained in uranyl acetate, dehydrated in ethanol and embedded in Spurr medium.

Centrosome Aurora A gradient ensures single polarity axis in C. elegans embryos

2020 ◽  
Vol 48 (3) ◽  
pp. 1243-1253 ◽  
Author(s):  
Sukriti Kapoor ◽  
Sachin Kotak
Keyword(s):  
Symmetry Breaking ◽  
Cell Fate ◽  
Cell Cortex ◽  
Axis Formation ◽  
Aurora A Kinase ◽  
Aurora A ◽  
C Elegans ◽  
Cell Embryo ◽  
Polarity Establishment

Cellular asymmetries are vital for generating cell fate diversity during development and in stem cells. In the newly fertilized Caenorhabditis elegans embryo, centrosomes are responsible for polarity establishment, i.e. anterior–posterior body axis formation. The signal for polarity originates from the centrosomes and is transmitted to the cell cortex, where it disassembles the actomyosin network. This event leads to symmetry breaking and the establishment of distinct domains of evolutionarily conserved PAR proteins. However, the identity of an essential component that localizes to the centrosomes and promotes symmetry breaking was unknown. Recent work has uncovered that the loss of Aurora A kinase (AIR-1 in C. elegans and hereafter referred to as Aurora A) in the one-cell embryo disrupts stereotypical actomyosin-based cortical flows that occur at the time of polarity establishment. This misregulation of actomyosin flow dynamics results in the occurrence of two polarity axes. Notably, the role of Aurora A in ensuring a single polarity axis is independent of its well-established function in centrosome maturation. The mechanism by which Aurora A directs symmetry breaking is likely through direct regulation of Rho-dependent contractility. In this mini-review, we will discuss the unconventional role of Aurora A kinase in polarity establishment in C. elegans embryos and propose a refined model of centrosome-dependent symmetry breaking.

scholarly journals Artificial Cell-Mediated Photodynamic Therapy Enhanced Anticancer Efficacy through Combination of Tumor Disruption and Immune Response Stimulation

ACS Omega ◽  
2019 ◽  
Vol 4 (7) ◽  
pp. 12727-12735 ◽  
Author(s):  
Jiang Ni ◽  
Ying Sun ◽  
Jinfang Song ◽  
Yiqing Zhao ◽  
Qiufang Gao ◽  
...  
Keyword(s):  
Immune Response ◽  
Photodynamic Therapy ◽  
Anticancer Efficacy ◽  
Artificial Cell

An artificial cell system for biocompatible gene delivery in cancer therapy

Nanoscale ◽  
2020 ◽  
Vol 12 (18) ◽  
pp. 10189-10195 ◽  
Author(s):  
Xin Zhao ◽  
Dongyang Tang ◽  
Ying Wu ◽  
Shaoqing Chen ◽  
Cheng Wang
Keyword(s):  
Gene Therapy ◽  
Cancer Therapy ◽  
Gene Delivery ◽  
Cancer Cells ◽  
Cell System ◽  
Artificial Cell

The artifical cell system for the gene therapy of cancer might be a promising approach for the reversal of neoplastic progress of cancer cells.

scholarly journals Giant Vesicles Produced with Phosphatidylcholines (PCs) and Phosphatidylethanolamines (PEs) by Water-in-Oil Inverted Emulsions

Life ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 223
Author(s):  
Boying Xu ◽  
Jinquan Ding ◽  
Jian Xu ◽  
Tetsuya Yomo
Keyword(s):  
Encapsulation Efficiency ◽  
Analytical Study ◽  
Giant Vesicles ◽  
Imaging Flow Cytometry ◽  
Artificial Cell ◽  
Transfer Method ◽  
Long Term Preservation ◽  
Natural Cell ◽  
Cell Construction

(1) Background: giant vesicles (GVs) are widely employed as models for studying physicochemical properties of bio-membranes and artificial cell construction due to their similarities to natural cell membranes. Considering the critical roles of GVs, various methods have been developed to prepare them. Notably, the water-in-oil (w/o) inverted emulsion-transfer method is reported to be the most promising, owning to the relatively higher productivity and better encapsulation efficiency of biomolecules. Previously, we successfully established an improved approach to acquire detailed information of 1-Palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC)-derived GVs with imaging flow cytometry (IFC); (2) Methods: we prepared GVs with different lipid compositions, including phosphatidylcholines (PCs), phosphatidylethanolamines (PEs), and PC/PE mixtures by w/o inverted emulsion methods. We comprehensively compared the yield, purity, size, and encapsulation efficiency of the resulting vesicles; (3) Results: the relatively higher productivities of GVs could be obtained from POPC, 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC), 1,2-dilauroyl-sn-glycero-3-phosphoethanolamine (DLPE), DOPC: DLPE (7:3), and POPC: DLPE (6:4) pools. Furthermore, we also demonstrate that these GVs are stable during long term preservation in 4 °C. (4) Conclusions: our results will be useful for the analytical study of GVs and GV-based applications.

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