scholarly journals The mobility of packaged phage genome controls ejection dynamics

eLife ◽  
2018 ◽  
Vol 7 ◽  
Author(s):  
Alex Evilevitch
Keyword(s):  
Latent Infection ◽  
Phage Genome ◽  
In Vitro Study ◽  
Limited Resources ◽  
Dna Injection ◽  
Dna Ejection ◽  
A Cell ◽  
Mechanical Transition ◽  
Phage Population

The cell decision between lytic and lysogenic infection is strongly influenced by dynamics of DNA injection into a cell from a phage population, as phages compete for limited resources and progeny. However, what controls the timing of viral DNA ejection events was not understood. This in vitro study reveals that DNA ejection dynamics for phages can be synchronized (occurring within seconds) or desynchronized (displaying minutes-long delays in initiation) based on mobility of encapsidated DNA, which in turn is regulated by environmental factors, such as temperature and extra-cellular ionic conditions. This mechano-regulation of ejection dynamics is suggested to influence viral replication where the cell’s decision between lytic and latent infection is associated with synchronized or desynchronized delayed ejection events from phage population adsorbed to a cell. Our findings are of significant importance for understanding regulatory mechanisms of latency in phage and Herpesviruses, where encapsidated DNA undergoes a similar mechanical transition.

The link between the AMPK/SIRT1 axis and a flavonoid‐rich extract of Citrus bergamia juice: A cell‐free, in silico, and in vitro study

2019 ◽  
Vol 33 (7) ◽  
pp. 1805-1814 ◽  
Author(s):  
Alessandro Maugeri ◽  
Nadia Ferlazzo ◽  
Laura De Luca ◽  
Rosaria Gitto ◽  
Michele Navarra
Keyword(s):  
In Silico ◽  
In Vitro Study ◽  
Vitro Study ◽  
A Cell ◽  
Citrus Bergamia

scholarly journals Polygalacturonase Isozymes Produced by Phomopsis cucurbitae in Relation to Postharvest Decay of Cantaloupe Fruit

1997 ◽  
Vol 87 (10) ◽  
pp. 1020-1025 ◽  
Author(s):  
Jiuxu Zhang ◽  
Benny D. Bruton ◽  
Charles L. Biles
Keyword(s):  
Latent Infection ◽  
Carbon Sources ◽  
Mature Fruit ◽  
Fruit Tissue ◽  
Fruit Maturity ◽  
Fruit Decay ◽  
A Cell ◽  
Tissue Maceration

Production of polygalacturonase (PG), a cell wall-degrading enzyme, by Phomopsis cucurbitae (latent infection fungus) was studied in relation to different carbon sources and various stages of cantaloupe fruit development. P. cucurbitae produced multiple PG isozymes both in vitro and in vivo. The fungus produced the highest PG activity and the greatest number of isozymes on pectin compared with those produced on glucose, galactose, and sucrose. Eight P. cucurbitae PG isozymes (pIs 3.7, 4.2, 6.6, 7.0, 7.3, 7.5, 7.8, and 8.6) were detected in extract from inoculated mature fruit (40 days after anthesis) by isoelectric focusing. Isozyme bands with pIs of 4.2, 7.3, and 7.8 were the most prominent. A similar set of PG isozymes was produced by P. cucurbitae in autoclaved mature fruit tissue (mesocarp). When tissue discs taken from 20-, 30-, 40-, and 50-day postanthesis fruit were inoculated with P. cucurbitae, PG activity and the number of PG isozymes extracted from the macerated fruit tissue discs increased with the degree of fruit maturity and ripening. Increases in PG activity and PG isozymes were also correlated with reactivation of latent infections and the beginning of tissue maceration. An anionic PG isozyme (pI 4.2) was only visualized on decayed 50-day-old fruit exocarp, as well as 40- and 50-day-old fruit mesocarp. The experimental results support the hypotheses that P. cucurbitae PG isozymes play an important role in fruit decay once latent infection becomes active following harvest.

Aged and Unaged Garlic Exerts Differential Effects on Cellular Aging via Modulation of Tissue Degradative and Antioxidant Enzymes Activity – A Cell-Free in Vitro Study

2017 ◽  
pp. 1-9
Keyword(s):  
Superoxide Dismutase ◽  
Antioxidant Enzymes ◽  
In Vitro Study ◽  
Cellular Aging ◽  
Vitro Study ◽  
Cell Aging ◽  
A Cell ◽  
Collagenase Inhibition ◽  
Aged Garlic

The effects of aged and unaged garlic on cell aging processes via enzymatic and oxidative pathways were examined in this cell-free in vitro study. Aged and unaged garlic, quercetin, and S-allyl cysteine inhibited collagenase and elastase dose-dependently. Quercetin and unaged garlic showed stronger collagenase inhibition and weaker elastase inhibition than S-allyl cysteine and aged garlic. Quercetin and aged garlic scavenged radicals more effectively than unaged garlic and S-allyl cysteine. Superoxide dismutase activity was significantly augmented by quercetin and unaged garlic when compared to aged garlic and S-allyl cysteine. Aged garlic contained higher amounts of S-allyl cysteine, total flavonoid and polyphenols, and lower quercetin content when compared to unaged garlic. Aged and unaged garlic exerted different effects on cellular aging by modulating collagenase, elastase, and superoxide dismutase activities. The different effects can potentially be attributed to different organosulfur and phenolic compositions.

scholarly journals High-Frequency, In Vitro Reversible Switching of Candida lusitaniae Clinical Isolates from Amphotericin B Susceptibility to Resistance

1999 ◽  
Vol 43 (4) ◽  
pp. 836-845 ◽  
Author(s):  
Stephanie A. Yoon ◽  
Jose A. Vazquez ◽  
Paul E. Steffan ◽  
Jack D. Sobel ◽  
Robert A. Akins
Keyword(s):  
Amphotericin B ◽  
High Frequency ◽  
Susceptibility Testing ◽  
Uv Light ◽  
In Vitro Study ◽  
Resistant Phenotype ◽  
Serious Infections ◽  
A Cell ◽  
Candida Lusitaniae

ABSTRACT Recent studies have revealed an increase in the incidence of serious infections caused by non-albicans Candidaspecies. Candida lusitaniae is of special interest because of its sporadic resistance to amphotericin B (AmB). The present in vitro study demonstrated that, unlike other Candidaspecies, C. lusitaniae isolates frequently generated AmB-resistant lineages form previously susceptible colonies. Cells switching from a resistant colony to a susceptible phenotype were also detected after treatment with either UV light, heat shock, or exposure to whole blood, all of which increased the frequency of switching. In some C. lusitaniae lineages, after a cell switched to a resistant phenotype, the resistant phenotype was stable; in other lineages, colonies were composed primarily of AmB-susceptible cells. Although resistant and susceptible lineages were identical in many aspects, their cellular morphologies were dramatically different. Switching mechanisms that involve exposure to antifungals may have an impact on antifungal therapeutic strategies as well as on standardized susceptibility testing of clinical yeast specimens.

Molecular Mechanisms of EML in AML1/ETO+ AML and Its Targeting Treatments

Blood ◽  
2014 ◽  
Vol 124 (21) ◽  
pp. 5953-5953
Author(s):  
Fan Yi Meng ◽  
Ling Jiang ◽  
Qingxiu Zhong ◽  
Li Chun Wang ◽  
Guopan Yu ◽  
...  
Keyword(s):  
Cell Migration ◽  
Protein Expression ◽  
Molecular Mechanisms ◽  
Conflicts Of Interest ◽  
Cell Model ◽  
In Vitro Study ◽  
Control Group ◽  
A Cell ◽  
App Gene

Abstract Our previous study has been reported that AML1/ETO positive patients with highly expressed of APP were much easier to extramedullary infiltration, and got poor prognosis£¨followed-up median 35 ( 6-96 ) months, RFS in the high expression APP group was significantly lower than the low expression group £¬40.0% vs 80.0%£¬P = 0.001). In vitro study, we constructed a cell model kasumi-1 which was consistent with AML1/ETO positive and high expressed of APP gene. The cell migration was significantly reduced after interferce of APP expression. This study was designed to investigate the molecule mechanism of extramedullary leukemia (EML) in kasumi-1 cell model and to invent a strategy for treatment in clinic. In this study, we found p-ERK, c-Myc and MMP-2 were significantly decreased after APP expression knockdown in kasumi-1 cell. Meanwhile, we added the inhibitors to block p-ERK and c-Myc expression. The results showed that protein expression of p-ERK and c-Myc was significantly decreased after p-ERK inhibitor performance, which was proportional to the time and concentration. c-Myc and MMP-2 protein expression was significantly reduced after c-Myc inhibitor was used, but p-ERK didn't change (Fig.1B). So, we concluded that APP might regulated the AML cell migration via APP/p-ERK/c-Myc/MMP-2 pathway. Also, we found that kasumi-1 cell was resistant to adriamycin (ADM) and Ara-C, which meant APP may be related with drug resistance. So, we detected cell surviving fraction after ADM and Ara-C performance via MTT assay. The results showed that there was no difference in control group and siAPP group. But, when compared with controls groups, cell surviving fraction in siEZH2 group was significantly decreased after ADM and Ara-C performance respectively. Furthermore, we found protein expression of EZH2 was significantly reduced after LBH589 treatment in cell culture. So, we concluded that LBH589 or SiEZH2 could increase sensitivity of kasumi-1 cell to ADM and Ara-C. In sum, in AML1/ETO positive leukemia cells, we first report that APP gene regulates cell migration via APP/p-ERK/c-Myc/MMP-2 pathway and EZH2 gene induces drug resistantence. Interference or blocking of EZH2 and APP expression may be helpful in treating AML1/ETO positive leukemia. Disclosures No relevant conflicts of interest to declare.

Preparation and Characterization of Agarose-Gelatin Blend Hydrogels as a Cell Encapsulation Matrix: An In-Vitro Study

2012 ◽  
Vol 51 (8) ◽  
pp. 1606-1616 ◽  
Author(s):  
Rana Imani ◽  
Shahriar Hojjati Emami ◽  
Parisa Rahnama Moshtagh ◽  
Nafiseh Baheiraei ◽  
Ali Mohammad Sharifi
Keyword(s):  
In Vitro Study ◽  
Cell Encapsulation ◽  
Vitro Study ◽  
A Cell

scholarly journals One size does not fit all: developing a cell-specific niche for in vitro study of cell behavior

2016 ◽  
Vol 52-54 ◽  
pp. 426-441 ◽  
Author(s):  
Milos Marinkovic ◽  
Travis J. Block ◽  
Rubie Rakian ◽  
Qihong Li ◽  
Exing Wang ◽  
...  
Keyword(s):  
In Vitro Study ◽  
Vitro Study ◽  
Cell Behavior ◽  
A Cell

Aged and Unaged Garlic Exerts Differential Effects on Cellular Aging via Modulation of Tissue Degradative and Antioxidant Enzymes Activity – A Cell-Free in Vitro Study

2017 ◽  
pp. 1-9
Keyword(s):  
Superoxide Dismutase ◽  
Antioxidant Enzymes ◽  
In Vitro Study ◽  
Cellular Aging ◽  
Vitro Study ◽  
Cell Aging ◽  
A Cell ◽  
Collagenase Inhibition ◽  
Aged Garlic

The effects of aged and unaged garlic on cell aging processes via enzymatic and oxidative pathways were examined in this cell-free in vitro study. Aged and unaged garlic, quercetin, and S-allyl cysteine inhibited collagenase and elastase dose-dependently. Quercetin and unaged garlic showed stronger collagenase inhibition and weaker elastase inhibition than S-allyl cysteine and aged garlic. Quercetin and aged garlic scavenged radicals more effectively than unaged garlic and S-allyl cysteine. Superoxide dismutase activity was significantly augmented by quercetin and unaged garlic when compared to aged garlic and S-allyl cysteine. Aged garlic contained higher amounts of S-allyl cysteine, total flavonoid and polyphenols, and lower quercetin content when compared to unaged garlic. Aged and unaged garlic exerted different effects on cellular aging by modulating collagenase, elastase, and superoxide dismutase activities. The different effects can potentially be attributed to different organosulfur and phenolic compositions.

Injection defect in alkylated and depurinated T7 bacteriophage: analysis by DNA ejection

1982 ◽  
Vol 60 (3) ◽  
pp. 232-242 ◽  
Author(s):  
M. D. Mamet-Bratley ◽  
M. Zollinger ◽  
B. Karska-Wysocki
Keyword(s):  
Rna Polymerase ◽  
Methyl Methanesulfonate ◽  
Dna Complexes ◽  
E Coli ◽  
Dna Injection ◽  
Dna Ejection ◽  
Phage Capsid ◽  
T7 Phage ◽  
T7 Bacteriophage

Using DNA ejection in vitro as a model, we have studied the DNA injection defect caused by alkylation and depurination of T7 bacteriophage. Phage was alkylated with 0.02 M methyl methanesulfonate for 2 h at 37 °C; alkylated phage was then incubated 24 h at 30 °C to induce depurination. These samples were treated with formamide to cause DNA ejection without dissociation of the phage capsid. After ejection, the phage preparations were analyzed by electron microscopy. DNA lengths in capsid–DNA complexes were measured; relative numbers of full, empty, and partially empty phage heads were determined. To establish the direction of DNA ejection, E. coli RNA polymerase was bound to capsid–DNA complexes. The results showed that DNA was partially ejected from both alkylated and depurinated phages. In the alkylated sample, RNA polymerase was bound to the DNA end distal to the capsid; this showed that ejection started from the genetic left end. We interpret these results to show, in confirmation of earlier results obtained by marker rescue, that alkylation causes T7 phage to partially inject its DNA, starting from the genetic left end. For depurinated phage, our results suggest that partial DNA injection is responsible, in this case as well, for the already documented injection defect.

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