scholarly journals New Shuttle Vectors for Real-Time Gene Expression Analysis in Multidrug-Resistant Acinetobacter Species: In Vitro and In Vivo Responses to Environmental Stressors

2019 ◽  
Vol 85 (18) ◽  
Author(s):  
Massimiliano Lucidi ◽  
Daniela Visaggio ◽  
Elisa Prencipe ◽  
Francesco Imperi ◽  
Giordano Rampioni ◽  
...  
Keyword(s):  
Gene Expression ◽  
Expression Analysis ◽  
Gene Expression Analysis ◽  
Multidrug Resistant ◽  
Antibiotic Selection ◽  
Content Type ◽  
Shuttle Vectors ◽  
Reporter Systems

ABSTRACT The Acinetobacter genus includes species of opportunistic pathogens and harmless saprophytes. The type species, Acinetobacter baumannii, is a nosocomial pathogen renowned for being multidrug resistant (MDR). Despite the clinical relevance of infections caused by MDR A. baumannii and a few other Acinetobacter spp., the regulation of their pathogenicity remains elusive due to the scarcity of adequate genetic tools, including vectors for gene expression analysis. Here, we report the generation and testing of a series of Escherichia coli-Acinetobacter promoter-probe vectors suitable for gene expression analysis in Acinetobacter spp. These vectors, named pLPV1Z, pLPV2Z, and pLPV3Z, carry both gentamicin and zeocin resistance markers and contain lux, lacZ, and green fluorescent protein (GFP) reporter systems downstream of an extended polylinker, respectively. The presence of a toxin-antitoxin gene system and the high copy number allow pLPV plasmids to be stably maintained even without antibiotic selection. The pLPV plasmids can easily be introduced by electroporation into MDR A. baumannii belonging to the major international lineages as well as into species of the Acinetobacter calcoaceticus-A. baumannii complex. The pLPV vectors have successfully been employed to study the regulation of stress-responsive A. baumannii promoters, including the DNA damage-inducible uvrABC promoter, the ethanol-inducible adhP and yahK promoters, and the iron-repressible promoter of the acinetobactin siderophore biosynthesis gene basA. A lux-tagged A. baumannii ATCC 19606T strain, carrying the iron-responsive pLPV1Z::PbasA promoter fusion, allowed in vivo and ex vivo monitoring of the bacterial burden in the Galleria mellonella infection model. IMPORTANCE The short-term adaptive response to environmental cues greatly contributes to the ecological success of bacteria, and profound alterations in bacterial gene expression occur in response to physical, chemical, and nutritional stresses. Bacteria belonging to the Acinetobacter genus are ubiquitous inhabitants of soil and water though some species, such as Acinetobacter baumannii, are pathogenic and cause serious concern due to antibiotic resistance. Understanding A. baumannii pathobiology requires adequate genetic tools for gene expression analysis, and to this end we developed user-friendly shuttle vectors to probe the transcriptional responses to different environmental stresses. Vectors were constructed to overcome the problem of antibiotic selection in multidrug-resistant strains and were equipped with suitable reporter systems to facilitate signal detection. By means of these vectors, the transcriptional response of A. baumannii to DNA damage, ethanol exposure, and iron starvation was investigated both in vitro and in vivo, providing insights into A. baumannii adaptation during stress and infection.

375 Gene expression analysis of galactosamine-induced hepatotoxicity in-vivo and in-vitro

2003 ◽  
Vol 144 ◽  
pp. s102
Author(s):  
H. Hildebrand ◽  
G. Kempka ◽  
H. Ellinger ◽  
B. Stuart ◽  
B. Wahle ◽  
...  
Keyword(s):  
Gene Expression ◽  
Expression Analysis ◽  
Gene Expression Analysis

Role of the snake venom toxin jararhagin in proinflammatory pathogenesis: In vitro and in vivo gene expression analysis of the effects of the toxin

2005 ◽  
Vol 441 (1) ◽  
pp. 1-15 ◽  
Author(s):  
Paul Gallagher ◽  
Yongde Bao ◽  
Solange M.T. Serrano ◽  
Gavin D. Laing ◽  
R. David G. Theakston ◽  
...  
Keyword(s):  
Gene Expression ◽  
Expression Analysis ◽  
Snake Venom ◽  
Gene Expression Analysis ◽  
Venom Toxin ◽  
Snake Venom Toxin

Human and murine amniotic fluid c-Kit+Lin− cells display hematopoietic activity

Blood ◽  
2009 ◽  
Vol 113 (17) ◽  
pp. 3953-3960 ◽  
Author(s):  
Andrea Ditadi ◽  
Paolo de Coppi ◽  
Olivier Picone ◽  
Laetitia Gautreau ◽  
Rim Smati ◽  
...  
Keyword(s):  
Gene Expression ◽  
Stem Cells ◽  
Amniotic Fluid ◽  
Expression Analysis ◽  
Gene Expression Analysis ◽  
Lymphoid Cells ◽  
Immunocompromised Hosts ◽  
Hematopoietic Activity

Abstract We have isolated c-Kit+Lin− cells from both human and murine amniotic fluid (AF) and investigated their hematopoietic potential. In vitro, the c-Kit+Lin− population in both species displayed a multilineage hematopoietic potential, as demonstrated by the generation of erythroid, myeloid, and lymphoid cells. In vivo, cells belonging to all 3 hematopoietic lineages were found after primary and secondary transplantation of murine c-Kit+Lin− cells into immunocompromised hosts, thus demonstrating the ability of these cells to self-renew. Gene expression analysis of c-Kit+ cells isolated from murine AF confirmed these results. The presence of cells with similar characteristics in the surrounding amnion indicates the possible origin of AF c-Kit+Lin− cells. This is the first report showing that cells isolated from the AF do have hematopoietic potential; our results support the idea that AF may be a new source of stem cells for therapeutic applications.

129 POST-HATCHING DEVELOPMENT AND GENE EXPRESSION OF IN VITRO-PRODUCED BOVINE EMBRYOS IN RECIPIENT UTERUS AFTER MULTIPLE TRANSFER

2013 ◽  
Vol 25 (1) ◽  
pp. 212
Author(s):  
G. Machado ◽  
A. Ferreira ◽  
I. Pivato ◽  
A. Fidelis ◽  
J. F. Srpicigo ◽  
...  
Keyword(s):  
Gene Expression ◽  
Expression Analysis ◽  
Gene Expression Analysis ◽  
T Test ◽  
Molecular Profile ◽  
Control Group ◽  
Fluid Medium ◽  
Uterine Flushing

This study aimed to compare post-hatching development of Day 7 in vitro and in vivo embryos cultured in recipient uterus until Day 14. For producing in vitro embryos (IVP), oocytes were matured, fertilized (Day 0) and cultured in vitro for 6 days (Day 7) in synthetic oviduct fluid medium supplemented with 5% of fetal bovine serum and incubated at 39°C in 5% CO2 in air. At Day 7, part of IVP blastocysts was transferred to recipient uterus and part was stored for gene expression analysis. As a control group, in vivo embryos were produced after ovarian stimulation, insemination and uterine flushing on Day 7 post insemination. Similarly to the IVP embryos, part of embryos was transferred to recipient uterus and part was stored for gene expression analysis. Day 7 in vivo (n = 53) and IVP (n = 64) expanded blastocysts were transferred to synchronized recipients (10/horn) and were collected by uterine flushing 7 days after transfer (Day 14). Recovered embryos were measured using Motic Image Plus software and evaluated for presence and size of embryonic disc (ED). A trophoblast biopsy was removed and stored for gene expression analysis. For the molecular profile evaluation of Day 7 and Day 14 in vivo and in vitro embryos, 8 genes related with placentation, implantation, oxidative stress, and glucose metabolism (PLAC8, CD9, GLUT-1, GLUT-3, KRT8, MnSOD, HSP70, and INFT, respectively) were quantified by RT-qPCR using ΔΔCT method and CYC-A gene as endogenous control. The recovery rate of Day 14 embryos, analyzed by chi-square test, was higher (P < 0.05) for in vitro than for in vivo embryos, being 50.0% (64/128) and 38.6% (53/137), respectively. No differences (P > 0.05; t-test) were observed in embryo length when comparing Day 14 in vitro (19.1 ± 2.4 mm) and in vivo embryos (24.2 ± 3.7 mm). ED was detected in 25% (16/64) of in vitro and in 26% (14/53) of in vivo embryos. No differences were found (P > 0.05; t-test) in diameter between the two types of embryos (0.3 ± 0.0 mm/in vitro and 0.3 ± 0.0 mm/in vivo). Regarding gene expression, Day 7 IVP embryos showed higher (P < 0.05, Mann–Whitney test) expression of HSP70 and SCL2A1 than in vivo embryos. However, at Day 14 no differences between embryos were observed in transcript levels for any of the studied genes. Therefore, the present study showed that although differences in Day 7 in vitro embryos were observed at the molecular level compared to in vivo counterpart, after transfer to the uterine environment, they showed similar morphology and gene expression profile. These results highlight the importance of evaluating embryos produced by assisted reproductive techniques in later stages of development to have a more precise evaluation of their quality. Financial support: Embrapa, CNPq, CAPES.

scholarly journals Cryptococcus neoformans Host Adaptation: Toward Biological Evidence of Dormancy

mBio ◽  
2015 ◽  
Vol 6 (2) ◽  
Author(s):  
Alexandre Alanio ◽  
Frédérique Vernel-Pauillac ◽  
Aude Sturny-Leclère ◽  
Françoise Dromer
Keyword(s):  
Gene Expression ◽  
Flow Cytometry ◽  
Cryptococcus Neoformans ◽  
Immune Cells ◽  
Gene Expression Analysis ◽  
Yeast Cells ◽  
Content Type ◽  
Dormant Cells

ABSTRACTCryptococcosis is an opportunistic infection due to the ubiquitous yeastCryptococcus neoformans. This yeast interacts closely with innate immune cells, leading to various fates, including fungal persistence within cells, making possible the dissemination of the yeast cells with monocytes via a Trojan horse strategy. In humans, the natural history of the infection begins with primoinfection during childhood, which is followed by dormancy and, in some individuals, reactivation upon immunosuppression. To address the question of dormancy, we studiedC. neoformansinfection at the macrophage level (in vitroH99-macrophage interaction) and at the organ level in a murine model of cryptococcosis. We analyzed the diversity of yeast adaptation to the host by characterizing severalC. neoformanspopulations with new assays based on flow cytometry (quantitative flow cytometry, multispectral imaging flow cytometry, sorting), microscopy (dynamic imaging), and gene expression analysis. On the basis of parameters of multiplication and stress response, various populations of yeast cells were observed over timein vivoandin vitro. Cell sorting allowed the identification of a subpopulation that was less prone to grow under standard conditions than the other populations, with growth enhanced by the addition of serum. Gene expression analysis revealed that this population had specific metabolic characteristics that could reflect dormancy. Our data suggest that dormant yeast cells could existin vitroandin vivo.C. neoformansexhibits a huge plasticity and adaptation to hosts that deserves further study.In vitrogeneration of dormant cells is now the main challenge to overcome the limited number of yeast cells recovered in our models.IMPORTANCECryptococcus neoformansis a sugar-coated unicellular fungus that interacts closely with various cells and organisms, including amoebas, nematodes, and immune cells of mammals. This yeast is able to proliferate and survive in the intracellular environment.C. neoformanscauses cryptococcosis, and yeast dormancy in humans has been suggested on the basis of epidemiological evidence obtained years ago. By studying anin vitromodel of yeast-macrophage interaction and murine models of cryptococcosis, we observed that yeast cells evolve in heterogeneous populations during infection on the basis of global metabolic activity. We compared the growth ability and gene expression of yeast cells belonging to various populations in those two models. We eventually found a population of yeast cells with low metabolism that fit some of the criteria for dormant cells. This paves the way for further characterization of dormancy inC. neoformans.

Gene Expression Analysis of Troglitazone Reveals Its Impact on Multiple Pathways in Cell Culture: A Case for In Vitro Platforms Combined with Gene Expression Analysis for Early (Idiosyncratic) Toxicity Screening

2006 ◽  
Vol 25 (2) ◽  
pp. 85-94 ◽  
Author(s):  
Gordon Vansant ◽  
Patrick Pezzoli ◽  
Robert Saiz ◽  
Aaron Birch ◽  
Chris Duffy ◽  
...  
Keyword(s):  
Gene Expression ◽  
Type 2 Diabetes ◽  
Expression Analysis ◽  
Gene Expression Analysis ◽  
Peroxisome Proliferator ◽  
Toxicity Screening ◽  
The Impact

Peroxisome proliferator-activated receptor gamma (PPAR γ) agonists of the thiazolidinedione family are used for the treatment of type 2 diabetes mellitus due to their ability to reduce glucose and lipid levels in patients with this disease. Three thiazolidinediones that were approved for treatment are Rezulin (troglitazone), Avandia (rosiglitazone), and Actos (pioglitazone). Troglitazone was withdrawn from the market due to idiosyncratic drug toxicity. Rosiglitazone and pioglitazone are still on the market for the treatment of type 2 diabetes. The authors present data from a gene expression screen that compares the impact these three compounds have in rats, in rat hepatocytes, and in the clone 9 rat liver cell line. The authors monitored the changes in expression in multiple genes, including those related to xenobiotic metabolism, proliferation, DNA damage, oxidative stress, apoptosis, and inflammation. Compared to the other two compounds, troglitazone had a significant impact on many of the pathways monitored in vitro although no major perturbation was detected in vivo. The changes detected predict not only general toxicity but potential mechanisms of toxicity. Based on gene expression analysis, the authors propose there is not just one but multiple ways troglitazone could be toxic, depending on a patient’s environment and genetic makeup, including immune response-related toxicity.

Cyclosporine A treated in vitro models induce cholestasis response through comparison of phenotype-directed gene expression analysis of in vivo Cyclosporine A-induced cholestasis

2013 ◽  
Vol 221 (3) ◽  
pp. 225-236 ◽  
Author(s):  
Anne S. Kienhuis ◽  
Alexa P. Vitins ◽  
Jeroen L.A. Pennings ◽  
Tessa E. Pronk ◽  
Ewoud N. Speksnijder ◽  
...  
Keyword(s):  
Gene Expression ◽  
Expression Analysis ◽  
Cyclosporine A ◽  
Gene Expression Analysis ◽  
In Vitro Models
Sign in / Sign up

Export Citation Format

Share Document