scholarly journals Using Live-Cell Imaging and Synthetic Biology to Probe Directed Migration in Dictyostelium

2021 ◽  
Vol 9 ◽  
Author(s):  
Jonathan Kuhn ◽  
Yiyan Lin ◽  
Peter N. Devreotes
Keyword(s):  
Synthetic Biology ◽  
Control Cell ◽  
Growth Cycle ◽  
Eukaryotic Cell ◽  
Cellular Motility ◽  
The Social ◽  
Invaluable Tool ◽  
Mechanical Networks ◽  
Single Living Cells

For decades, the social amoeba Dictyostelium discoideum has been an invaluable tool for dissecting the biology of eukaryotic cells. Its short growth cycle and genetic tractability make it ideal for a variety of biochemical, cell biological, and biophysical assays. Dictyostelium have been widely used as a model of eukaryotic cell motility because the signaling and mechanical networks which they use to steer and produce forward motion are highly conserved. Because these migration networks consist of hundreds of interconnected proteins, perturbing individual molecules can have subtle effects or alter cell morphology and signaling in major unpredictable ways. Therefore, to fully understand this network, we must be able to quantitatively assess the consequences of abrupt modifications. This ability will allow us better control cell migration, which is critical for development and disease, in vivo. Here, we review recent advances in imaging, synthetic biology, and computational analysis which enable researchers to tune the activity of individual molecules in single living cells and precisely measure the effects on cellular motility and signaling. We also provide practical advice and resources to assist in applying these approaches in Dictyostelium.

Shall I trust you? From child human-robot interaction to trusting relationships

2019 ◽  
Author(s):  
Cinzia Di Dio ◽  
Federico Manzi ◽  
Giulia Peretti ◽  
Angelo Cangelosi ◽  
Paul L. Harris ◽  
...  
Keyword(s):  
Behavioral Pattern ◽  
Human Robot Interaction ◽  
School Age Children ◽  
Social Relevance ◽  
Robot Interaction ◽  
Cognitive Correlates ◽  
The Social ◽  
The Relationship

Studying trust within human-robot interaction is of great importance given the social relevance of robotic agents in a variety of contexts. We investigated the acquisition, loss and restoration of trust when preschool and school-age children played with either a human or a humanoid robot in-vivo. The relationship between trust and the quality of attachment relationships, Theory of Mind, and executive function skills was also investigated. No differences were found in children’s trust in the play-partner as a function of agency (human or robot). Nevertheless, 3-years-olds showed a trend toward trusting the human more than the robot, while 7-years-olds displayed the reverse behavioral pattern, thus highlighting the developing interplay between affective and cognitive correlates of trust.

iTSP-PseAAC: Identify Tumor Suppressor Proteins by Using Fully Connected Neural Network and PseAAC

2021 ◽  
Vol 15 ◽  
Author(s):  
Muhammad Awais ◽  
Waqar Hussain ◽  
Nouman Rasool ◽  
Yaser Daanial Khan
Keyword(s):  
Tumor Suppressor ◽  
Cross Validation ◽  
Control Cell ◽  
Normal Function ◽  
In Vivo Studies ◽  
Tumor Suppressor Proteins ◽  
Proposed Model ◽  
Self Consistency

Background: The uncontrolled growth due to accumulation of genetic and epigenetic changes as a result of loss or reduction in the normal function of Tumor Suppressor Genes (TSGs) and Pro-oncogenes is known as cancer. TSGs control cell division and growth by repairing of DNA mistakes during replication and restrict the unwanted proliferation of a cell or activities, those are the part of tumor production. Objectives: This study aims to propose a novel, accurate, user-friendly model to predict tumor suppressor proteins, which would be freely available to experimental molecular biologists to assist them using in vitro and in vivo studies. Methods: The predictor model has used the input feature vector (IFV) calculated from the physicochemical properties of proteins based on FCNN to compute the accuracy, sensitivity, specificity, and MCC. The proposed model was validated against different exhaustive validation techniques i.e. self-consistency and cross-validation. Results: Using self-consistency, the accuracy is 99%, for cross-validation and independent testing has 99.80% and 100% accuracy respectively. The overall accuracy of the proposed model is 99%, sensitivity value 98% and specificity 99% and F1-score was 0.99. Conclusion: It concludes, the proposed model for prediction of the tumor suppressor proteins can predict the tumor suppressor proteins efficiently, but it still has space for improvements in computational ways as the protein sequences may rapidly increase, day by day.

scholarly journals Anticancer Compounds Derived from Marine Diatoms

Marine Drugs ◽  
2020 ◽  
Vol 18 (7) ◽  
pp. 356 ◽  
Author(s):  
Hanaa Ali Hussein ◽  
Mohd Azmuddin Abdullah
Keyword(s):  
Unsaturated Fatty Acids ◽  
High Surface ◽  
High Surface Area ◽  
Drug Carriers ◽  
Growth Cycle ◽  
In Vivo Studies ◽  
High Yield ◽  
Anti Cancer ◽  
Nano Medicine

Cancer is the main cause of death worldwide, so the discovery of new and effective therapeutic agents must be urgently addressed. Diatoms are rich in minerals and secondary metabolites such as saturated and unsaturated fatty acids, esters, acyl lipids, sterols, proteins, and flavonoids. These bioactive compounds have been reported as potent anti-cancer, anti-oxidant and anti-bacterial agents. Diatoms are unicellular photosynthetic organisms, which are important in the biogeochemical circulation of silica, nitrogen, and carbon, attributable to their short growth-cycle and high yield. The biosilica of diatoms is potentially effective as a carrier for targeted drug delivery in cancer therapy due to its high surface area, nano-porosity, bio-compatibility, and bio-degradability. In vivo studies have shown no significant symptoms of tissue damage in animal models, suggesting the suitability of a diatoms-based system as a safe nanocarrier in nano-medicine applications. This review presents an overview of diatoms’ microalgae possessing anti-cancer activities and the potential role of the diatoms and biosilica in the delivery of anticancer drugs. Diatoms-based antibodies and vitamin B12 as drug carriers are also elaborated.

scholarly journals RAE-1 ligands for the NKG2D receptor are regulated by E2F transcription factors, which control cell cycle entry

2012 ◽  
Vol 209 (13) ◽  
pp. 2409-2422 ◽  
Author(s):  
Heiyoun Jung ◽  
Benjamin Hsiung ◽  
Kathleen Pestal ◽  
Emily Procyk ◽  
David H. Raulet
Keyword(s):  
Cell Cycle ◽  
Transcription Factors ◽  
Stress Responses ◽  
Transcriptional Activation ◽  
Posttranscriptional Regulation ◽  
Cellular Proliferation ◽  
Control Cell ◽  
T Cell Subsets ◽  
Cell Cycle Entry

The NKG2D stimulatory receptor expressed by natural killer cells and T cell subsets recognizes cell surface ligands that are induced on transformed and infected cells and facilitate immune rejection of tumor cells. We demonstrate that expression of retinoic acid early inducible gene 1 (RAE-1) family NKG2D ligands in cancer cell lines and proliferating normal cells is coupled directly to cell cycle regulation. Raet1 genes are directly transcriptionally activated by E2F family transcription factors, which play a central role in regulating cell cycle entry. Induction of RAE-1 occurred in primary cell cultures, embryonic brain cells in vivo, and cells in healing skin wounds and, accordingly, wound healing was delayed in mice lacking NKG2D. Transcriptional activation by E2Fs is likely coordinated with posttranscriptional regulation by other stress responses. These findings suggest that cellular proliferation, as occurs in cancer cells but also other pathological conditions, is a key signal tied to immune reactions mediated by NKG2D-bearing lymphocytes.

scholarly journals A Decade of Imaging Cellular Motility and Interaction Dynamics in the Immune System

Science ◽  
2012 ◽  
Vol 336 (6089) ◽  
pp. 1676-1681 ◽  
Author(s):  
Ronald N. Germain ◽  
Ellen A. Robey ◽  
Michael D. Cahalan
Keyword(s):  
Lymph Nodes ◽  
Live Cell Imaging ◽  
Quantitative Measurement ◽  
Cell Imaging ◽  
Plasma Cells ◽  
Effector T Cells ◽  
Cellular Interactions ◽  
Cellular Motility ◽  
Response Dynamics

To mount an immune response, lymphocytes must recirculate between the blood and lymph nodes, recognize antigens upon contact with specialized presenting cells, proliferate to expand a small number of clonally relevant lymphocytes, differentiate to antibody-producing plasma cells or effector T cells, exit from lymph nodes, migrate to tissues, and engage in host-protective activities. All of these processes involve motility and cellular interactions—events that were hidden from view until recently. Introduced to immunology by three papers in this journal in 2002, in vivo live-cell imaging studies are revealing the behavior of cells mediating adaptive and innate immunity in diverse tissue environments, providing quantitative measurement of cellular motility, interactions, and response dynamics. Here, we review themes emerging from such studies and speculate on the future of immunoimaging.

scholarly journals Dominant-Negative FADD Rescues the In Vivo Fitness of a Cytomegalovirus Lacking an Antiapoptotic Viral Gene

2007 ◽  
Vol 82 (5) ◽  
pp. 2056-2064 ◽  
Author(s):  
Luka Čičin-Šain ◽  
Zsolt Ruzsics ◽  
Juergen Podlech ◽  
Ivan Bubić ◽  
Carine Menard ◽  
...  
Keyword(s):  
Virus Replication ◽  
Control Cell ◽  
Death Receptor ◽  
Formal Proof ◽  
Dominant Negative ◽  
Viral Fitness ◽  
Viral Gene ◽  
Apoptosis Inhibition

ABSTRACT Genes that inhibit apoptosis have been described for many DNA viruses. Herpesviruses often contain even more than one gene to control cell death. Apoptosis inhibition by viral genes is postulated to contribute to viral fitness, although a formal proof is pending. To address this question, we studied the mouse cytomegalovirus (MCMV) protein M36, which binds to caspase-8 and blocks death receptor-induced apoptosis. The growth of MCMV recombinants lacking M36 (ΔM36) was attenuated in vitro and in vivo. In vitro, caspase inhibition by zVAD-fmk blocked apoptosis in ΔM36-infected macrophages and rescued the growth of the mutant. In vivo, ΔM36 infection foci in liver tissue contained significantly more apoptotic hepatocytes and Kupffer cells than did revertant virus foci, and apoptosis occurred during the early phase of virus replication prior to virion assembly. To further delineate the mode of M36 function, we replaced the M36 gene with a dominant-negative FADD (FADDDN) in an MCMV recombinant. FADDDN was expressed in cells infected with the recombinant and blocked the death-receptor pathway, replacing the antiapoptotic function of M36. Most importantly, FADDDN rescued ΔM36 virus replication, both in vitro and in vivo. These findings have identified the biological role of M36 and define apoptosis inhibition as a key determinant of viral fitness.

scholarly journals Tandem Translation Generates a Chaperone for the Salmonella Type III Secretion System Protein SsaQ

2011 ◽  
Vol 286 (41) ◽  
pp. 36098-36107 ◽  
Author(s):  
Xiu-Jun Yu ◽  
Mei Liu ◽  
Steve Matthews ◽  
David W. Holden
Keyword(s):  
Type Iii Secretion ◽  
Ex Vivo ◽  
Eukaryotic Cell ◽  
Effector Proteins ◽  
Secretion Systems ◽  
Type Iii ◽  
Type Iii Secretion Systems ◽  
Function Loss ◽  
Bacterial Cytoplasm

Type III secretion systems (T3SSs) of bacterial pathogens involve the assembly of a surface-localized needle complex, through which translocon proteins are secreted to form a pore in the eukaryotic cell membrane. This enables the transfer of effector proteins from the bacterial cytoplasm to the host cell. A structure known as the C-ring is thought to have a crucial role in secretion by acting as a cytoplasmic sorting platform at the base of the T3SS. Here, we studied SsaQ, an FliN-like putative C-ring protein of the Salmonella pathogenicity island 2 (SPI-2)-encoded T3SS. ssaQ produces two proteins by tandem translation: a long form (SsaQL) composed of 322 amino acids and a shorter protein (SsaQS) comprising the C-terminal 106 residues of SsaQL. SsaQL is essential for SPI-2 T3SS function. Loss of SsaQS impairs the function of the T3SS both ex vivo and in vivo. SsaQS binds to its corresponding region within SsaQL and stabilizes the larger protein. Therefore, SsaQL function is optimized by a novel chaperone-like protein, produced by tandem translation from its own mRNA species.

Motility of the Limulus blood cell

1979 ◽  
Vol 37 (1) ◽  
pp. 169-180
Author(s):  
P.B. Armstrong
Keyword(s):  
Tissue Culture ◽  
Time Lapse ◽  
Coelomic Fluid ◽  
Cellular Motility ◽  
Paraffin Oil ◽  
Motile Cells ◽  
Direct Microscopic Examination ◽  
High Concentrations ◽  
Glass Surfaces

The sole cell type (the amoebocyte) found in the coelomic fluid of the horseshoe crab, Limulus polyphemus can be stimulated to become motile by extravasation or trauma. Motility was studied using time-lapse microcinematography and direct microscopic examination of cells in tissue culture and in gill leaflets isolated from young animals. Phase-contrast and Nomarski differential-interference contrast optics were employed. Both in culture and in the gills, motile cells showed 2 interconvertible morphological types: the contracted cell, which was compact and rounded and had a relatively small area of contact with the substratum, and a flattened from with a larger area of contact. In both morphological types, motility involved the protrusion of hyaline pseudopods followed by flow of granular endoplasm forward in the pseudoplod. Cellular motility in vivo (in the gill leaflet) was morphologically identical to that displayed in tissue culture. In culture, motility was unaffected by the nature of the substratum: cells were indistinguishable on fluid (paraffin oil) or solid (glass) substrata or on hydrophobic (paraffin oil, siliconized glass) or hydrophilic (clean glass) surfaces. Cells migrated and spread on agar surfaces. Cell motility was unaffected by high concentrations (100 micrograms/ml) of the microtubule-depolymerizing agent colcemid and was abolished by cytochalasin B at 1 microgram/ml.

In vitro modulation of endothelial fenestrae: opposing effects of retinoic acid and transforming growth factor beta

1988 ◽  
Vol 91 (2) ◽  
pp. 313-318
Author(s):  
T. Lombardi ◽  
R. Montesano ◽  
M.B. Furie ◽  
S.C. Silverstein ◽  
L. Orci
Keyword(s):  
Endothelial Cells ◽  
Retinoic Acid ◽  
Growth Factor ◽  
Transforming Growth Factor Beta ◽  
Surface Density ◽  
Transforming Growth Factor ◽  
Control Cell ◽  
Tgf Beta ◽  
Growth Factor Beta

Cultured endothelial cells isolated from fenestrated capillaries express many properties characteristic of their in vivo differentiated phenotype, including the formation of a limited number of fenestrae. In this study, we have investigated whether physiological factors that control cell differentiation might regulate the surface density of fenestrae in capillary endothelial cells. We have found that treatment of the cultures with retinoic acid (10 microM) induces a more than threefold increase in the surface density of endothelial fenestrae, whereas transforming growth factor beta (TGF beta) (2 ng ml-1) causes a sevenfold decrease in the surface density of these structures. These results show that the expression of endothelial fenestrae is susceptible to bidirectional modulation by physiological signals, and suggest that retinoids and TGF beta may participate in the regulation of fenestral density of capillary endothelium in vivo.

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