Global Transcriptomic Analysis During Murine Pneumonia Infection Reveals New Virulence Factors in Acinetobacter baumannii

Author(s):  
Marta Martínez-Guitián ◽  
Juan C Vázquez-Ucha ◽  
Laura Álvarez-Fraga ◽  
Kelly Conde-Pérez ◽  
Juan A Vallejo ◽  
...  

Abstract Background Infections caused by multidrug-resistant pathogens such as Acinetobacter baumannii constitute a major health problem worldwide. In this study we present a global in vivo transcriptomic analysis of A. baumannii isolated from the lungs of mice with pneumonia infection. Methods Mice were infected with A. baumannii ATCC 17978 and AbH12O-A2 strains and the total bacterial RNA were analyzed by RNA sequencing. Lists of differentially expressed genes were obtained and 14 of them were selected for gene deletion and further analysis. Results Transcriptomic analysis revealed a specific gene expression profile in A. baumannii during lung infection with upregulation of genes involved in iron acquisition and host invasion. Mutant strains lacking feoA, mtnN, yfgC, basB, hisF, oatA, and bfnL showed a significant loss of virulence in murine pneumonia. A decrease in biofilm formation, adherence to human epithelial cells, and growth rate was observed in selected mutants. Conclusions This study provides an insight into A. baumannii gene expression profile during murine pneumonia infection. Data revealed that 7 in vivo upregulated genes were involved in virulence and could be considered new therapeutic targets.

Author(s):  
P. Agretti ◽  
G. De Marco ◽  
E. Ferrarini ◽  
C. Di Cosmo ◽  
L. Montanelli ◽  
...  

Abstract Purpose Toxic multinodular goiter is a heterogeneous disease associated with hyperthyroidism frequently detected in areas with deficient iodine intake, and functioning and non-functioning nodules, characterized by increased proliferation but opposite functional activity, may coexist in the same gland. To understand the distinct molecular pathology of each entity present in the same gland, the gene expression profile was evaluated by using the Affymetrix technology. Methods Total RNA was extracted from nodular and healthy tissues of two patients and double-strand cDNA was synthesized. Biotinylated cRNA was obtained and, after chemical fragmentation, was hybridized on U133A and B arrays. Each array was stained and the acquired images were analyzed to obtain the expression levels of the transcripts. Both functioning and non-functioning nodules were compared versus healthy tissue of the corresponding patient. Results About 16% of genes were modulated in functioning nodules, while in non-functioning nodules only 9% of genes were modulated with respect to the healthy tissue. In functioning nodules of both patients and up-regulation of cyclin D1 and cyclin-dependent kinase inhibitor 1 was observed, suggesting the presence of a possible feedback control of proliferation. Complement components C1s, C7 and C3 were down-regulated in both types of nodules, suggesting a silencing of the innate immune response. Cellular fibronectin precursor was up-regulated in both functioning nodules suggesting a possible increase of endothelial cells. Finally, Frizzled-1 was down-regulated only in functioning nodules, suggesting a role of Wnt signaling pathway in the proliferation and differentiation of these tumors. None of the thyroid-specific gene was deregulated in microarray analysis. Conclusion In conclusion, the main finding from our data is a similar modulation for both kinds of nodules in genes possibly implicated in thyroid growth.


Pathogens ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 471
Author(s):  
Camila Pimentel ◽  
Casin Le ◽  
Marisel R. Tuttobene ◽  
Tomas Subils ◽  
Jasmine Martinez ◽  
...  

Acinetobacter baumannii is a nosocomial pathogen capable of causing serious infections associated with high rates of morbidity and mortality. Due to its antimicrobial drug resistance profile, A. baumannii is categorized as an urgent priority pathogen by the Centers for Disease Control and Prevention in the United States and a priority group 1 critical microorganism by the World Health Organization. Understanding how A. baumannii adapts to different host environments may provide critical insights into strategically targeting this pathogen with novel antimicrobial and biological therapeutics. Exposure to human fluids was previously shown to alter the gene expression profile of a highly drug-susceptible A. baumannii strain A118 leading to persistence and survival of this pathogen. Herein, we explore the impact of human pleural fluid (HPF) and human serum albumin (HSA) on the gene expression profile of a highly multi-drug-resistant strain of A. baumannii AB5075. Differential expression was observed for ~30 genes, whose products are involved in quorum sensing, quorum quenching, iron acquisition, fatty acid metabolism, biofilm formation, secretion systems, and type IV pilus formation. Phenotypic and further transcriptomic analysis using quantitative RT-PCR confirmed RNA-seq data and demonstrated a distinctive role of HSA as the molecule involved in A. baumannii’s response.


2008 ◽  
Vol 34 (1) ◽  
pp. 9-21 ◽  
Author(s):  
Angela M. Verdoni ◽  
Natsuyo Aoyama ◽  
Akihiro Ikeda ◽  
Sakae Ikeda

Remodeling of the actin cytoskeleton through actin dynamics (assembly and disassembly of filamentous actin) is known to be essential for numerous basic biological processes. In addition, recent studies have provided evidence that actin dynamics participate in the control of gene expression. A spontaneous mouse mutant, corneal disease 1 ( corn1), is deficient for a regulator of actin dynamics, destrin (DSTN, also known as ADF), which causes epithelial hyperproliferation and neovascularization in the cornea. Dstn corn1 mice exhibit an actin dynamics defect in the corneal epithelial cells, offering an in vivo model to investigate cellular mechanisms affected by the Dstn mutation and resultant actin dynamics abnormalities. To examine the effect of the Dstn corn1 mutation on the gene expression profile, we performed a microarray analysis using the cornea from Dstn corn1 and wild-type mice. A dramatic alteration of the gene expression profile was observed in the Dstn corn1 cornea, with 1,226 annotated genes differentially expressed. Functional annotation of these genes revealed that the most significantly enriched functional categories are associated with actin and/or cytoskeleton. Among genes that belong to these categories, a considerable number of serum response factor target genes were found, indicating the possible existence of an actin-SRF pathway of transcriptional regulation in vivo. A comparative study using an allelic mutant strain with milder corneal phenotypes suggested that the level of filamentous actin may correlate with the level of gene expression changes. Our study shows that Dstn mutations and resultant actin dynamics abnormalities have a strong impact on the gene expression profile in vivo.


2002 ◽  
Vol 2 (1) ◽  
pp. 57-64 ◽  
Author(s):  
K Regnström ◽  
E G E Ragnarsson ◽  
N Rydell ◽  
I Sjöholm ◽  
P Artursson

2010 ◽  
Vol 94 (4) ◽  
pp. S88
Author(s):  
Z.G. Ouandaogo ◽  
S. Assou ◽  
D. Haouzi ◽  
T. Anahory ◽  
H. Dechaud ◽  
...  

2010 ◽  
Vol 104 (7) ◽  
pp. 941-950 ◽  
Author(s):  
Kenji Saito ◽  
Yutaka Ohta ◽  
Manabu Sami ◽  
Tomomasa Kanda ◽  
Hisanori Kato

Recent transcriptomics studies on the effect of long-term or severe energy restriction (ER) have revealed that many genes are dynamically modulated by this condition in rodents. The present study was conducted to define the global gene expression profile in response to mild ER treatment. Growing rats were fed with reduced amount of diet (5–30 % ER) for 1 week or 1 month. Using DNA microarray analysis of the liver, seventy-two genes that were consistently changed through the different ER levels were identified. Many were related to lipid metabolism including genes encoding key enzymes such as carnitine palmitoyltransferase 1 and fatty acid synthase. Interestingly, a number of genes were altered even by 5 % ER for 1 week where no differences in weight gain were observed. The information obtained in the present study can be used as a valuable reference data source in the transcriptomics studies of food and nutrition in which subtle differences in food intake sometimes hinder appropriate interpretation of the data.


2007 ◽  
Vol 27 (11) ◽  
pp. 4082-4092 ◽  
Author(s):  
Andrew J. Bingham ◽  
Lezanne Ooi ◽  
Lukasz Kozera ◽  
Edward White ◽  
Ian C. Wood

ABSTRACT Cardiac hypertrophy is associated with a dramatic change in the gene expression profile of cardiac myocytes. Many genes important during development of the fetal heart but repressed in the adult tissue are reexpressed, resulting in gross physiological changes that lead to arrhythmias, cardiac failure, and sudden death. One transcription factor thought to be important in repressing the expression of fetal genes in the adult heart is the transcriptional repressor REST (repressor element 1-silencing transcription factor). Although REST has been shown to repress several fetal cardiac genes and inhibition of REST function is sufficient to induce cardiac hypertrophy, the molecular mechanisms employed in this repression are not known. Here we show that continued REST expression prevents increases in the levels of the BNP (Nppb) and ANP (Nppa) genes, encoding brain and atrial natriuretic peptides, in adult rat ventricular myocytes in response to endothelin-1 and that inhibition of REST results in increased expression of these genes in H9c2 cells. Increased expression of Nppb and Nppa correlates with increased histone H4 acetylation and histone H3 lysine 4 methylation of promoter-proximal regions of these genes. Furthermore, using deletions of individual REST repression domains, we show that the combined activities of two domains of REST are required to efficiently repress transcription of the Nppb gene; however, a single repression domain is sufficient to repress the Nppa gene. These data provide some of the first insights into the molecular mechanism that may be important for the changes in gene expression profile seen in cardiac hypertrophy.


Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 3409-3409
Author(s):  
Paola Neri ◽  
Pierfrancesco Tassone ◽  
Masood Shammas ◽  
Mariateresa Fulciniti ◽  
Yu-Tzu Tai ◽  
...  

Abstract Interaction between multiple myeloma (MM) cells and the bone marrow (BM) microenvironment plays a critical role in promoting MM cell growth, survival, migration and development of drug resistance. This interaction within the bone marrow milieu is unique and its understanding is important in evaluating effects of novel agents in vitro and in vivo. We here describe a novel murine model that allows us to study the expression changes in vivo in MM cells within the human BM milieu. In this model, the green fluorescent protein (INA-6 GFP+) transduced IL-6-dependent human MM cell line, INA-6, was injected in human bone chip implanted into SCID mice. At different time points the bone chip was retrieved, cells flushed out and GFP+ MM cells were purified by CD138 MACS microbeads. Similar isolation process was used on INA-6 GFP+ cells cultured in vitro and used as control. Total RNA was isolated from these cells and gene expression profile analyzed using the HG-U133 array chip (Affymetrix) and DChip analyzer program. We have identified significant changes in expression of several genes following in vivo interaction between INA-6 and the BM microenvironment. Specifically, we observed up-regulation of genes associated with cytokines (IL-4, IL-8, IGFB 2–5) and chemokines (CCL2, 5, 6, 18, 24, CCR1, 2, 4), implicated in cell-cell signalling. Moreover genes implicated in DNA transcription (V-Fos, V-Jun, V-kit), adhesion (Integrin alpha 2b, 7, cadherin 1 and 11) and cell growth (CDC14, Cyclin G2, ADRA1A) were also up-regulated and genes involved in apoptosis and cell death (p-57, BCL2, TNF1a) were down-regulated. Using the Ingenuity Pathway Analysis the most relevant pathways modulated by the in vivo interaction between MM cells and BMSCs were IL-6, IGF1, TGF-beta and ERK/MAPK-mediated pathways as well as cell-cycle regulation and chemokine signalling. These results are consistent with previously observed in vitro cell signalling studies. Taken together these results highlight the ability of BM microenvironment to modulate the gene expression profile of the MM cells and our ability to in vivo monitor the changes. This model thus provides us with an ability to study in vivo effects of novel agents on expression profile of MM cells in BM milieu, to pre-clinically characterize their activity.


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