scholarly journals Burkholderia cenocepacia transcriptome during the early contacts with giant plasma membrane vesicles derived from live bronchial epithelial cells

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Andreia I. Pimenta ◽  
Nuno Bernardes ◽  
Marta M. Alves ◽  
Dalila Mil-Homens ◽  
Arsenio M. Fialho

AbstractBurkholderia cenocepacia is known for its capacity of adherence and interaction with the host, causing severe opportunistic lung infections in cystic fibrosis patients. In this work we produced Giant Plasma Membrane Vesicles (GPMVs) from a bronchial epithelial cell line and validated their use as a cell-like alternative to investigate the steps involved in the adhesion process of B. cenocepacia. RNA-sequencing was performed and the analysis of the B. cenocepacia K56-2 transcriptome after the first contacts with the surface of host cells allowed the recognition of genes implicated in bacterial adaptation and virulence-associated functions. The sensing of host membranes led to a transcriptional shift that caused a cascade of metabolic and physiological adaptations to the host specific environment. Many of the differentially expressed genes encode proteins related with central metabolic pathways, transport systems, cellular processes, and virulence traits. The understanding of the changes in gene expression that occur in the early steps of infection can uncover new proteins implicated in B. cenocepacia-host cell adhesion, against which new blocking agents could be designed to control the progression of the infectious process.

1989 ◽  
Vol 264 (1) ◽  
pp. 223-231 ◽  
Author(s):  
T C Williams ◽  
A J Doherty ◽  
D A Griffith ◽  
S M Jarvis

The transport of uridine into rabbit renal outer-cortical brush-border and basolateral membrane vesicles was compared at 22 degrees C. Uridine was taken up into an osmotically active space in the absence of metabolism for both types of membrane vesicles. Uridine influx by brush-border membrane vesicles was stimulated by Na+, and in the presence of inwardly directed gradients of Na+ a transient overshoot phenomenon was observed, indicating active transport. Kinetic analysis of the saturable Na+-dependent component of uridine flux indicated that it was consistent with Michaelis-Menten kinetics (Km 12 +/- 3 microM, Vmax. 3.9 +/- 0.9 pmol/s per mg of protein). The sodium:uridine coupling stoichiometry was found to be consistent with 1:1 and involved the net transfer of positive charge. In contrast, uridine influx by basolateral membrane vesicles was not dependent on the cation present and was inhibited by nitrobenzylthioinosine (NBMPR). NBMPR-sensitive uridine transport was saturable (Km 137 +/- 20 microM, Vmax. 5.2 +/- 0.6 pmol/s per mg of protein). Inhibition of uridine flux by NBMPR was associated with high-affinity binding of NBMPR to the basolateral membrane (Kd 0.74 +/- 0.46 nM). Binding of NBMPR to these sites was competitively blocked by adenosine and uridine. These results indicate that uridine crosses the brush-border surface of rabbit proximal renal tubule cells by Na+-dependent pathways, but permeates the basolateral surface by NBMPR-sensitive facilitated-diffusion carriers.


2004 ◽  
Vol 286 (4) ◽  
pp. L777-L785 ◽  
Author(s):  
Kei Takamura ◽  
Yasuyuki Nasuhara ◽  
Motoko Kobayashi ◽  
Tomoko Betsuyaku ◽  
Yoko Tanino ◽  
...  

Retinoic acid (RA) is known to accelerate wound healing and induce cell differentiation. All- trans RA (ATRA) exerts its effect by binding retinoic acid receptors, which are members of the nuclear receptor family. We investigated whether RA can alter expression of eotaxin, a potent eosinophil chemoattractant that is regulated by the transcription factors signal transducer and activator of transcription 6 (STAT6) and NF-κB. We examined the effects of RA on eotaxin expression in a human bronchial epithelial cell line BEAS-2B. ATRA and its stereodimer 9- cis retinoic acid (9- cis RA) inhibited IL-4-induced release of eotaxin at 10-6M by 78.0 and 52.0%, respectively ( P < 0.05). ATRA and 9- cis RA also significantly inhibited IL-4-induced eotaxin mRNA expression at 10-6M by 52.3 and 53.5%, respectively ( P < 0.05). In contrast, neither ATRA nor 9- cis RA had any effects on TNF-α-induced eotaxin production. In transfection studies using eotaxin promoter luciferase plasmids, the inhibitory effect of ATRA on IL-4-induced eotaxin production was confirmed at the transcriptional level. Interestingly, ATRA had no effects on IL-4-induced tyrosine phosphorylation, nuclear translocation, or DNA binding activity of STAT6. Activating protein-1 was not involved in ATRA-mediated transrepression of eotaxin with IL-4 stimulation. The mechanism of the inhibitory effect of ATRA on IL-4-induced eotaxin production in human bronchial epithelial cells has not been elucidated but does not appear to be due to an effect on STAT6 activation. These findings raise the possibility that RA may reduce eosinophilic airway inflammation, one of the prominent pathological features of allergic diseases such as bronchial asthma.


2021 ◽  
Author(s):  
Yan Wang ◽  
Xin Zuo ◽  
Fuyang Jiang ◽  
Lin Hou ◽  
Qiyue Jiang ◽  
...  

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.


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