scholarly journals Thermoplasmonic neural chip platform for in situ manipulation of neuronal connections in vitro

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Nari Hong ◽  
Yoonkey Nam
Keyword(s):  
Neuronal Networks ◽  
Structural Changes ◽  
Cell Culture Techniques ◽  
Culture Techniques ◽  
Functional Changes ◽  
Functional Relationships ◽  
Functional Dynamics ◽  
Controlled Structure

AbstractCultured neuronal networks with a controlled structure have been widely studied as an in vitro model system to investigate the relationship between network structure and function. However, most cell culture techniques lack the ability to control network structures during cell cultivation, making it difficult to assess functional changes induced by specific structural changes. In this study, we present an in situ manipulation platform based on gold-nanorod-mediated thermoplasmonics to interrogate an in vitro network model. We find that it is possible to induce new neurite outgrowths, eliminate interconnecting neurites, and estimate functional relationships in matured neuronal networks. This method is expected to be useful for studying functional dynamics of neural networks under controlled structural changes.

scholarly journals In Vitro Lung Models and Their Application to Study SARS-CoV-2 Pathogenesis and Disease

Viruses ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 792
Author(s):  
Natalie Heinen ◽  
Mara Klöhn ◽  
Eike Steinmann ◽  
Stephanie Pfaender
Keyword(s):  
Cell Culture ◽  
Ex Vivo ◽  
Treatment Options ◽  
Pharmaceutical Companies ◽  
Cell Culture Techniques ◽  
Culture Techniques ◽  
Novel Treatment ◽  
Cell Culture Systems ◽  
Drug Efficiency

SARS-CoV-2 has spread across the globe with an astonishing velocity and lethality that has put scientist and pharmaceutical companies worldwide on the spot to develop novel treatment options and reliable vaccination for billions of people. To combat its associated disease COVID-19 and potentially newly emerging coronaviruses, numerous pre-clinical cell culture techniques have progressively been used, which allow the study of SARS-CoV-2 pathogenesis, basic replication mechanisms, and drug efficiency in the most authentic context. Hence, this review was designed to summarize and discuss currently used in vitro and ex vivo cell culture systems and will illustrate how these systems will help us to face the challenges imposed by the current SARS-CoV-2 pandemic.

scholarly journals Conformational Flexibility and Local Frustration in the Functional States of the SARS-CoV-2 Spike B.1.1.7 and B.1.351 Variants: Mutation-Induced Allosteric Modulation Mechanism of Functional Dynamics and Protein Stability

2021 ◽  
Author(s):  
Gennady Verkhivker
Keyword(s):  
Protein Stability ◽  
Cell Receptor ◽  
Spike Protein ◽  
Coarse Grained ◽  
Virus Infectivity ◽  
Functional Changes ◽  
Conformational Substates ◽  
Functional Relationships ◽  
Functional Dynamics ◽  
Open States

The experimental and computational studies of the SARS-CoV-2 spike protein variants revealed an important role of the D614G mutation that is shared across variants of concern(VOCs), linking the effect of this mutation with the enhanced virus infectivity and transmissibility. The recent structural and biophysical studies characterized the closed and open states of the B.1.1.7 (B.1.1.7) and B.1.351 (Beta) spike variants allowing for a more detailed atomistic characterization of the conformational landscapes and functional changes. In this study, we employed coarse-grained simulations of the SARS-CoV-2 spike variant trimers together with the ensemble-based mutational frustration analysis to characterize the dynamics signatures of the conformational landscapes. By combining the local frustration analysis of the conformational ensembles with collective dynamics and residue-based mutational scanning of protein stability, we determine protein stability hotspots and identify potential energetic drivers favoring the receptor-accessible open spike states for the B.1.1.7 and B.1.351 spike variants. Through mutational scanning of protein stability changes we quantify mutational adaptability of the S-G614, S-B.1.1.7 and S-B.1.351 variants in different functional forms. Using this analysis, we found a significant conformational and mutational plasticity of the open states for all studied variants. The results of this study suggest that modulation of the energetic frustration at the inter-protomer interfaces can serve as a mechanism for allosteric couplings between mutational sites, the inter-protomer hinges of functional motions and motions of the receptor-binding domain required for binding of the host cell receptor. The proposed mechanism of mutation-induced energetic frustration may result in the greater adaptability and the emergence of multiple conformational substates in the open form. This study also suggested functional relationships between mutation-induced modulation of protein dynamics, local frustration and allosteric regulation of the SARS-CoV-2 spike protein.

Effect ofSchistosoma mansoni-induced granulomatous inflammation on murine gastrointestinal motility

2001 ◽  
Vol 280 (5) ◽  
pp. G1030-G1042 ◽  
Author(s):  
Tom G. Moreels ◽  
Joris G. De Man ◽  
Johannes J. Bogers ◽  
Benedicte Y. De Winter ◽  
Gunther Vrolix ◽  
...  
Keyword(s):  
Structural Changes ◽  
Gastrointestinal Transit ◽  
Granulomatous Inflammation ◽  
Muscle Layer ◽  
Gastric Fundus ◽  
Smooth Muscle Contractility ◽  
Functional Changes ◽  
Mucosal Thickness

In Schistosoma mansoni-infected mice, gastrointestinal transit was measured in vivo and the neuromuscular function of longitudinal muscle strips of inflamed ileum and noninflamed gastric fundus was assessed in vitro. Eight weeks after infection, the ileal wall was acutely inflamed, as shown by a mucosal inflammatory infiltrate, leading to an increase in mucosal thickness, in myeloperoxidase (MPO) activity, and in interleukin (IL)-1β production. At that time, both gastrointestinal transit and in vitro ileal contractility were normal. Twelve weeks after infection, chronic granulomatous inflammation led to proliferation of the muscle layer and to a further increase in MPO activity, whereas IL-1β production normalized. Gastrointestinal transit was decreased, whereas in vitro ileal contractility was increased irrespective of the contractile stimulus. In vitro incubation with IL-1β (10 ng/ml for 60 min) significantly increased ileal contractility only at 8 wk after infection. Indomethacin, tetrodotoxin, and atropine had no differential effect on ileal contractility in controls and infected mice. In vitro contractility of noninflamed gastric fundus was normal both 8 and 12 wk after infection. We conclude that intestinal schistosomiasis 8 wk after infection is associated only with structural changes of the ileum, whereas 12 wk after infection, both structural and functional changes are present. These changes are characterized by increased ileal wall thickness, decreased gastrointestinal transit, and increased smooth muscle contractility restricted to the inflamed gut segment.

Physico-Chemical Studies of Isolated Chromatin Compared with in situ Chromatin after Partial Hepatectomy in the Rat

1979 ◽  
Vol 34 (5-6) ◽  
pp. 442-448 ◽  
Author(s):  
Paul Miller ◽  
Walfried A. Linden ◽  
Claudio Nicolini
Keyword(s):  
Partial Hepatectomy ◽  
Conformational Changes ◽  
Quaternary Structure ◽  
Cultured Cells ◽  
Fluorescence Emission ◽  
Chromatin Organization ◽  
Chromatin Conformation ◽  
Functional Changes

Abstract Chromatin was isolated from rat liver cells at 0, 3, 5, 11, 18 and 24 h following partial hepatectomy. Consistent with findings in cultured cells stimulated to proliferate, there was an increase in chromatin molar ellipticity measured at 276 nm, and a decrease in thermal stability 3 to 8 h after surgery. These events occured prior to the onset of DNA synthesis. These early changes be­ tween non-proliferating (G0) and proliferating (G1) cells, as well as later chromatin conformational changes observed at S and G2 phases, mimic changes in template activity.Results with sheared and unsheared chromatin (both with in vitro and in vivo systems) prove that structural and functional changes can be caused by even the slightest shearing during chromatin preparation, suggesting the loss of native chromatin organization. To eliminate this problem, experiments were also conducted using chromatin in situ. A flow cytometer (FCM) was used to study unfixed liver cell suspensions stained with ethidium bromide (EB). Fluorescence was mea­ sured in the green spectral range after addition of increasing amounts of EB. Experimental evidence is provided that the same alteration in chromatin conformation can be best detected using low molar ratios of EB per unit DNA due to greater fluorescence emission in G1 respect to G0 cells.These correlated studies demonstrate that the same changes controlling chromatin organization in situ are detected also in the tertiary-quaternary structure of “isolated” chromatin. These changes in chromatin conformation are macromolecular events related to cell proliferation both at the G0 -G1 and G1 -S transitions.

scholarly journals Vessel-on-a-chip models for studying microvascular physiology, transport, and function in vitro

2020 ◽  
Author(s):  
Savannah R. Moses ◽  
Jonathan J. Adorno ◽  
Andre F. Palmer ◽  
Jonathan W. Song
Keyword(s):  
Cell Culture ◽  
Tissue Level ◽  
Culture Conditions ◽  
Cell Culture Techniques ◽  
Culture Techniques ◽  
Microscale Flow ◽  
Flow Phenomena ◽  
Defined Culture ◽  
And Function

To understand how the microvasculature grows and remodels, researchers require reproducible systems that emulate the function of living tissue. Innovative contributions toward fulfilling this important need have been made by engineered microvessels assembled in vitro using microfabrication techniques. Microfabricated vessels, commonly referred to as "vessels on a chip," are from a class of cell culture technologies that uniquely integrate microscale flow phenomena, tissue-level biomolecular transport, cell-cell interactions, and proper 3-D extracellular matrix environments under well-defined culture conditions. Here, we discuss the enabling attributes of microfabricated vessels that make these models more physiological compared to established cell culture techniques, and the potential of these models for advancing microvascular research. This review highlights the key features of microvascular transport and physiology, critically discusses the strengths and limitations of different microfabrication strategies for studying the microvasculature, and provides a perspective on current challenges and future opportunities for vessel on a chip models.

scholarly journals Microtissues in Cardiovascular Medicine: Regenerative Potential Based on a 3D Microenvironment

2016 ◽  
Vol 2016 ◽  
pp. 1-20 ◽  
Author(s):  
Julia Günter ◽  
Petra Wolint ◽  
Annina Bopp ◽  
Julia Steiger ◽  
Elena Cambria ◽  
...  
Keyword(s):  
Therapeutic Potential ◽  
Retention Rate ◽  
3D Cell Culture ◽  
Traditional Role ◽  
Cell Culture Techniques ◽  
Cell Therapies ◽  
Culture Techniques ◽  
3D Microenvironment

More people die annually from cardiovascular diseases than from any other cause. In particular, patients who suffer from myocardial infarction may be affected by ongoing adverse remodeling processes of the heart that may ultimately lead to heart failure. The introduction of stem and progenitor cell-based applications has raised substantial hope for reversing these processes and inducing cardiac regeneration. However, current stem cell therapies using single-cell suspensions have failed to demonstrate long-lasting efficacy due to the overall low retention rate after cell delivery to the myocardium. To overcome this obstacle, the concept of 3D cell culture techniques has been proposed to enhance therapeutic efficacy and cell engraftment based on the simulation of an in vivo-like microenvironment. Of great interest is the use of so-called microtissues or spheroids, which have evolved from their traditional role as in vitro models to their novel role as therapeutic agents. This review will provide an overview of the therapeutic potential of microtissues by addressing primarily cardiovascular regeneration. It will accentuate their advantages compared to other regenerative approaches and summarize the methods for generating clinically applicable microtissues. In addition, this review will illustrate the unique properties of the microenvironment within microtissues that makes them a promising next-generation therapeutic approach.

Study on the anti bovine viral diarrhea virus effect of swainsonine extract of Astragalus strictus Grah Ex Bend in vitro

2016 ◽  
Author(s):  
Jianping Liang ◽  
Yonghao Hu ◽  
Baocheng Hao ◽  
Xiaoyong Xing ◽  
Fanling Wu ◽  
...  
Keyword(s):  
Bovine Viral Diarrhea Virus ◽  
Bovine Viral Diarrhea ◽  
Cell Culture Techniques ◽  
Bovine Kidney ◽  
Culture Techniques ◽  
Diarrhea Virus ◽  
Viral Diarrhea ◽  
Observation Method ◽  
Viral Diarrhea Virus

This study was designed to investigate anti-virus action of the swainsonine (SW) extract of Astragalus strictus Grah. Ex Bend on bovine viral diarrhea virus (BVDV). Using cell culture techniques, and combining cytopathic effect (CPE) observation method and methyl thiazolyl tetrazolium (MTT) method to detect the toxicities of different concentrations of SW in bovine kidney primary cells (Madin-Darby Bovine Kidney Cells, MDBK), determine the drug safety concentration and TD50, Testing the comprehensive effect of different concentrations of SW for BVDV by adding swainsonine after virus-and-swainsonine added. The results showed that the TCID50 of BVDV is 10-4.7; there is no toxicity to MDBK when the concentration of SW below 0.256,mg·mL-1, and TD50 is 2.512mg·mL-1; Under the way of comprehensive action, IC50 is 0.782mg·mL-1,TI is 3.21. it showed that the comprehensive effect on BVDV of SW (65.29%, P less than 0.01) is good. The anti-BVDV effect of swainsonine in vitro is good and the antiviral mechanism of SW was speculated to SW inhibit the replication of BVDV proliferation or directly inactivate free BVDV.

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