scholarly journals Pseudomonas two-partner secretion toxin Exolysin contributes to insect killing

2019 ◽  
Author(s):  
Viviana Job ◽  
Stéphanie Bouillot ◽  
Erwan Gueguen ◽  
Mylène Robert-Genthon ◽  
Peter Panchev ◽  
...  
Keyword(s):  
Epithelial Cell ◽  
Pore Formation ◽  
Biocontrol Agent ◽  
Phytopathogenic Fungi ◽  
Membrane Transporter ◽  
Pseudomonas Chlororaphis ◽  
Gene Encoding ◽  
Outer Membrane Transporter ◽  
The Impact ◽  
Wax Moth

AbstractPseudomonas chlororaphis is a promising biocontrol agent promoting plant-growth and providing protection against pest insects and phytopathogenic fungi. We have identified in the genome of P. chlororaphis PA23 an operon encoding the toxin Exolysin (ExlA) and its outer-membrane transporter, ExlB. We found that P. chlororaphis producing ExlA (ExlAPch) is cytotoxic towards murine macrophages and human epithelial cells at 30 °C. P. chlororaphis PA23 provoked shrinkage of epithelial cell, leakage of cytoplasmic components and subsequent cell death. During infection, ExlAPch incorporated into epithelial cell membranes within detergent-resistant lipid rafts, suggesting the same mechanisms of cell destruction by pore-formation as reported for P. aeruginosa toxin. ExlAPch was not involved in the capacity of the strain to kill fungi, amoeba or other bacteria. The contribution of ExlA in insecticidal activity of P. chlororaphis was evaluated in the wax moth larvae Galleria mallonella and in Drosophila melanogaster flies. The impact of the deletion of a gene encoding exlA homologue was tested in the natural fly pathogen P. entonomophila. In both models, the ExlA absence delayed killing, suggesting the contribution of the toxin in bacteria-insect pathogenic interactions.

scholarly journals The Role of Mitochondria in Carcinogenesis

2021 ◽  
Vol 22 (10) ◽  
pp. 5100
Author(s):  
Paulina Kozakiewicz ◽  
Ludmiła Grzybowska-Szatkowska ◽  
Marzanna Ciesielka ◽  
Jolanta Rzymowska
Keyword(s):  
Prostate Cancer ◽  
Mitochondrial Dna ◽  
Nuclear Dna ◽  
Dna Polymorphisms ◽  
Gene Encoding ◽  
Dna Mutations ◽  
Nadh Ubiquinone Oxidoreductase ◽  
Gene Coi ◽  
The Impact

The mitochondria are essential for normal cell functioning. Changes in mitochondrial DNA (mtDNA) may affect the occurrence of some chronic diseases and cancer. This process is complex and not entirely understood. The assignment to a particular mitochondrial haplogroup may be a factor that either contributes to cancer development or reduces its likelihood. Mutations in mtDNA occurring via an increase in reactive oxygen species may favour the occurrence of further changes both in mitochondrial and nuclear DNA. Mitochondrial DNA mutations in postmitotic cells are not inherited, but may play a role both in initiation and progression of cancer. One of the first discovered polymorphisms associated with cancer was in the gene NADH-ubiquinone oxidoreductase chain 3 (mt-ND3) and it was typical of haplogroup N. In prostate cancer, these mutations and polymorphisms involve a gene encoding subunit I of respiratory complex IV cytochrome c oxidase subunit 1 gene (COI). At present, a growing number of studies also address the impact of mtDNA polymorphisms on prognosis in cancer patients. Some of the mitochondrial DNA polymorphisms occur in both chronic disease and cancer, for instance polymorphism G5913A characteristic of prostate cancer and hypertension.

scholarly journals Solubility assessment of single-chain antibody fragment against epithelial cell adhesion molecule extracellular domain in four Escherichia coli strains

2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Fatemeh Sadat Javadian ◽  
Majid Basafa ◽  
Aidin Behravan ◽  
Atieh Hashemi
Keyword(s):  
Escherichia Coli ◽  
Cell Adhesion ◽  
Epithelial Cell ◽  
Adhesion Molecule ◽  
Cell Adhesion Molecule ◽  
Extracellular Domain ◽  
Epithelial Cell Adhesion Molecule ◽  
Single Chain ◽  
E Coli ◽  
The Impact

Abstract Background Overexpression of the EpCAM (epithelial cell adhesion molecule) in malignancies makes it an attractive target for passive immunotherapy in a wide range of carcinomas. In comparison with full-length antibodies, due to the small size, the scFvs (single-chain variable fragments) are more suitable for recombinant expression in E. coli (Escherichia coli). However, the proteins expressed in large amounts in E. coli tend to form inclusion bodies that need to be refolded which may result in poor recovery of bioactive proteins. Various engineered strains were shown to be able to alleviate the insolubility problem. Here, we studied the impact of four E. coli strains on the soluble level of anti-EpEX-scFv (anti-EpCAM extracellular domain-scFv) protein. Results Although results showed that the amount of soluble anti-EpEX-scFv obtained in BL21TM (DE3) (114.22 ± 3.47 mg/L) was significantly higher to those produced in the same condition in E. coli RosettaTM (DE3) (71.39 ± 0.31 mg/L), and OrigamiTM T7 (58.99 ± 0.44 mg/L) strains, it was not significantly different from that produced by E. coli SHuffleTM T7 (108.87 ± 2.71 mg/L). Furthermore, the highest volumetric productivity of protein reached 318.29 ± 26.38 mg/L in BL21TM (DE3). Conclusions Although BL21TM (DE3) can be a suitable strain for high-level production of anti-EpEX-scFv protein, due to higher solubility yield (about 55%), E. coli SHuffleTM T7 seems to be better candidate for soluble production of scfv compared to BL21TM (DE3) (solubility yield of about 30%).

scholarly journals Defects in Mitochondrial and Peroxisomal β-Oxidation Influence Virulence in the Maize Pathogen Ustilago maydis

2012 ◽  
Vol 11 (8) ◽  
pp. 1055-1066 ◽  
Author(s):  
Matthias Kretschmer ◽  
Jana Klose ◽  
James W. Kronstad
Keyword(s):  
Ustilago Maydis ◽  
Short Chain Fatty Acids ◽  
Phytopathogenic Fungi ◽  
Metabolic Adaptation ◽  
In Planta ◽  
Gene Encoding ◽  
Disease Symptoms ◽  
Content Type ◽  
C Terminus ◽  
Fungal Phytopathogens

ABSTRACTAn understanding of metabolic adaptation during the colonization of plants by phytopathogenic fungi is critical for developing strategies to protect crops. Lipids are abundant in plant tissues, and fungal phytopathogens in the phylum basidiomycota possess both peroxisomal and mitochondrial β-oxidation pathways to utilize this potential carbon source. Previously, we demonstrated a role for the peroxisomal β-oxidation enzyme Mfe2 in the filamentous growth, virulence, and sporulation of the maize pathogenUstilago maydis. However,mfe2mutants still caused disease symptoms, thus prompting a more detailed investigation of β-oxidation. We now demonstrate that a defect in thehad1gene encoding hydroxyacyl coenzyme A dehydrogenase for mitochondrial β-oxidation also influences virulence, although its paralog,had2, makes only a minor contribution. Additionally, we identified a gene encoding a polypeptide with similarity to the C terminus of Mfe2 and designated it Mfe2b; this gene makes a contribution to virulence only in the background of anmfe2Δ mutant. We also show that short-chain fatty acids induce cell death inU. maydisand that a block in β-oxidation leads to toxicity, likely because of the accumulation of toxic intermediates. Overall, this study reveals that β-oxidation has a complex influence on the formation of disease symptoms byU. maydisthat includes potential metabolic contributions to proliferationin plantaand an effect on virulence-related morphogenesis.

A GacS deficiency does not affectPseudomonas chlororaphisPA23 fitness when growing on canola, in aged batch culture or as a biofilm

2006 ◽  
Vol 52 (12) ◽  
pp. 1177-1188 ◽  
Author(s):  
N Poritsanos ◽  
C Selin ◽  
W G.D Fernando ◽  
S Nakkeeran ◽  
T.R. de Kievit
Keyword(s):  
Antifungal Activity ◽  
Batch Culture ◽  
Hydrogen Cyanide ◽  
Fungal Pathogen ◽  
Biocontrol Agent ◽  
Antifungal Compounds ◽  
Pseudomonas Chlororaphis ◽  
Wild Type ◽  
Biocontrol Activity ◽  
Competition Assays

Pseudomonas chlororaphis PA23 is a biocontrol agent that protects against the fungal pathogen Sclerotinia sclerotiorum. Employing transposon mutagenesis, we isolated a gacS mutant that no longer exhibited antifungal activity. Pseudomonas chlororaphis PA23 was previously reported to produce the nonvolatile antibiotics phenazine 1-carboxylic acid and 2-hydroxyphenazine. We report here that PA23 produces additional compounds, including protease, lipase, hydrogen cyanide, and siderophores, that may contribute to its biocontrol ability. In the gacS mutant background, generation of these products was markedly reduced or delayed with the exception of siderophores, which were elevated. Not surprisingly, this mutant was unable to protect canola from disease incited by S. sclerotiorum. The gacS mutant was able to sustain itself in the canola phyllosphere, therefore, the loss of biocontrol activity can be attributed to a reduced production of antifungal compounds and not a declining population size. Competition assays between the mutant and wild type revealed equivalent fitness in aged batch culture; consequently, the gacS mutation did not impart a growth advantage in the stationary phase phenotype. Under minimal nutrient conditions, the gacS-deficient strain produced a tenfold less biofilm than the wild type. However, no difference was observed in the ability of the mutant biofilm to protect cells from lethal antibiotic challenge.Key words: Pseudomonas, biocontrol, gacS, fitness, biofilms.

scholarly journals The activities of LRRK2 and GCase are positively correlated in clinical biospecimens and experimental models of Parkinson’s disease

2021 ◽  
Author(s):  
Maria Kedariti ◽  
Emanuele Frattini ◽  
Pascale Baden ◽  
Susanna Cogo ◽  
Laura Civiero ◽  
...  
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Kinase Activity ◽  
Experimental Models ◽  
Cellular Functions ◽  
Gene Encoding ◽  
Cellular Models ◽  
Lrrk2 Kinase ◽  
The Impact ◽  
Lrrk2 Kinase Activity

AbstractLRRK2 is a kinase involved in different cellular functions, including autophagy, endolysosomal pathways and vesicle trafficking. Mutations in LRRK2 cause autosomal dominant forms of Parkinson’s disease (PD). Heterozygous mutations in GBA1, the gene encoding the lysosomal enzyme glucocerebrosidase (GCase), are the most common genetic risk factors for PD. Moreover, GCase function is altered in idiopathic PD and in other genetic forms of the disease. Recent work suggests that LRRK2 kinase activity can regulate GCase function. However, both a positive and a negative correlation have been described. To gain insights into the impact of LRRK2 on GCase, we investigated GCase levels and activity in LRRK2 G2019S knockin mice, in clinical biospecimens from PD patients carrying this mutation and in patient-derived cellular models. In these models we found a positive correlation between the activities of LRRK2 and GCase, which was further confirmed in cell lines with genetic and pharmacological manipulation of LRRK2 kinase activity. Overall, our study indicates that LRRK2 kinase activity affects both the levels and the catalytic activity of GCase.

scholarly journals Impact of the Neuregulin rs35753505 C/T Polymorphisms on Neuregulin 1 Levels in Preterm Infants

2019 ◽  
Vol 7 (12) ◽  
pp. 1931-1934
Author(s):  
Bugis Mardina Lubis ◽  
Sjarif Hidajat Effendi ◽  
Ratna Akbari Ganie ◽  
Oke Rina Ramayani
Keyword(s):  
Preterm Infants ◽  
Cross Sectional Study ◽  
Enzyme Linked Immunosorbent Assay ◽  
P Value ◽  
Nucleotide Polymorphisms ◽  
Gene Encoding ◽  
Cross Sectional ◽  
Neuregulin 1 ◽  
Organ Systems ◽  
The Impact

BACKGROUND: Neuregulin (NRG) 1 plays an important role in the development of various organ systems in human. Single nucleotide polymorphisms rs35753505 C/Tof the gene encoding NRG1 evident as allele C and T with genotypes of CT, CC, and TT are believed to have an impact on NRG1 levels.AIM: To determine the impact of the NRGrs35753505 C/T polymorphisms on NRG1 levels in preterm infants.METHODS: A cross-sectional study was conducted from February to December 2018, whereas 48 eligible preterm infants with a gestational age of 32- < 37 weeks were enrolled. An umbilical cord blood specimen was collected for determination of NRG1 levels with enzyme-linked immunosorbent assay (ELISA) and NRG1 polymorphisms with polymerase chain reaction (PCR). Statistical analysis was performed with 95%CI and P value of < 0.05 was considered statistically significant.RESULTS: Median value of NRG1 levels (174.4 pg/ml) served as a cut off value. NRG 1 polymorphisms composed distribution of CC (31%), CT (42%), TT (27%) genotypes and distribution of C and T alleles were 52% and 48%. The median NRG1 levels in CC and CT genotypes were significantly lower compared to TT genotype (151.1 pg/ml vs 407.2 pg/ml, P = 0.005 and 159.1 pg/ml vs 407.2 pg/ml, P = 0.009). Subjects with C allele had significantly lower median NRG1 levels than T allele (151.1 pg/ml vs 407.2 pg/ml, P = 0.002). Subjects with CC and CT genotypes had higher risk to develop lower NRG1 levels compared to TT genotype (OR = 8.25, P = 0.016 and OR = 10.74, P = 0.005, respectively).CONCLUSION: Allele C is associated with lower NRG1 levels. Preterm infants with CC and CT genotypes pose a higher risk to have lower NRG1 levels.

scholarly journals A Comparative Study on the Model of PM2.5 Direct or Indirect Interaction with Bronchial Epithelial Cells.

2021 ◽  
Author(s):  
Yan Wang ◽  
Xin Zuo ◽  
Fuyang Jiang ◽  
Lin Hou ◽  
Qiyue Jiang ◽  
...  
Keyword(s):  
Epithelial Cell ◽  
Epithelial Cells ◽  
Cell Damage ◽  
Direct Interaction ◽  
Bronchial Epithelial Cell ◽  
Human Bronchial Epithelial Cell ◽  
Exposure Model ◽  
Epithelial Cell Line ◽  
Bronchial Epithelial ◽  
The Impact

Abstract The impact of PM2.5 on epithelial cells is a pivotal process leading to many lung pathological changes and pulmonary diseases. In addition to PM2.5 direct interaction with epithelia, macrophages that engulf PM2.5 may also influence the function of epithelial cells. However, among the toxic researches of PM2.5, there is a lack of evaluation of direct or indirect exposure model on human bronchial epithelial cell against PM2.5. In this present research, PM2.5-exposed human bronchial epithelial cell line (BEAS-2B) serves as the direct interaction model, while the contrast is to indirect stimulation model, which takes advantage of transwell co-culture system to carry out that PM2.5 is promptly contacted with macrophages rather than BEAS-2B. By comparing these two modes of interaction, we determined the viability of BEAS-2B and mRNA and/or protein expression profile of transcription factors Nrf2,NF-kB and according inflammatory indicators, with a view to evaluating the effects of different interaction modes of PM2.5 on epithelial cell damage in vitro. We have found that macrophage involvement may protect epithelia from PM2.5 cytotoxic effect, while strengthen the inflammation response.

The effect of polyhydroxyalkanoates in Pseudomonas chlororaphis PA23 biofilm formation, stress endurance, and interaction with the protozoan predator Acanthamoeba castellanii

2021 ◽  
pp. 1-15
Author(s):  
Akrm Ghergab ◽  
Nisha Mohanan ◽  
Grace Saliga ◽  
Ann Karen C. Brassinga ◽  
David Levin ◽  
...  
Keyword(s):  
Biofilm Formation ◽  
Acanthamoeba Castellanii ◽  
Pseudomonas Chlororaphis ◽  
Enhanced Sensitivity ◽  
Hostile Environments ◽  
The Impact ◽  
Environmental Fitness ◽  
Root Attachment

Pseudomonas chlororaphis PA23 is a biocontrol agent capable of protecting canola against the fungal pathogen Sclerotinia sclerotiorum. In addition to producing antifungal compounds, this bacterium synthesizes and accumulates polyhydroxyalkanoate (PHA) polymers as carbon and energy storage compounds. Because the role of PHA in PA23 physiology is currently unknown, we investigated the impact of this polymer on stress resistance, adherence to surfaces, and interaction with the protozoan predator Acanthamoeba castellanii. Three PHA biosynthesis mutants were created, PA23phaC1, PA23phaC1ZC2, and PA23phaC1ZC2D, which accumulated reduced PHA. Our phenotypic assays revealed that PA23phaC1ZC2D produced less phenazine (PHZ) compared with the wild type (WT) and the phaC1 and phaC1ZC2 mutants. All three mutants exhibited enhanced sensitivity to UV irradiation, starvation, heat stress, cold stress, and hydrogen peroxide. Moreover, motility, exopolysaccharide production, biofilm formation, and root attachment were increased in strains with reduced PHA levels. Interaction studies with the amoeba A. castellanii revealed that the WT and the phaC1 and phaC1ZC2 mutants were consumed less than the phaC1ZC2D mutant, likely due to decreased PHZ production by the latter. Collectively these findings indicate that PHA accumulation enhances PA23 resistance to a number of stresses in vitro, which could improve the environmental fitness of this bacterium in hostile environments.

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