scholarly journals Physiological and Transcriptional Responses of Candida parapsilosis to Exogenous Tyrosol

2019 ◽  
Vol 85 (20) ◽  
Author(s):  
Ágnes Jakab ◽  
Zoltán Tóth ◽  
Fruzsina Nagy ◽  
Dániel Nemes ◽  
Ildikó Bácskay ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Gene Expression ◽  
Stress Response ◽  
Ethanol Fermentation ◽  
Ribosome Biogenesis ◽  
Candida Parapsilosis ◽  
Efflux Pump ◽  
Oxidative Stress Response ◽  
Antifungal Effect ◽  
Content Type

ABSTRACT Tyrosol plays a key role in fungal morphogenesis and biofilm development. Also, it has a remarkable antifungal effect at supraphysiological concentrations. However, the background of the antifungal effect remains unknown, especially in the case of non-albicans Candida species such as Candida parapsilosis. We examined the effect of tyrosol on growth, adhesion, redox homeostasis, virulence, as well as fluconazole susceptibility. To gain further insights into the physiological consequences of tyrosol treatment, we also determined genome-wide gene expression changes using transcriptome sequencing (RNA-Seq). A concentration of 15 mM tyrosol caused significant growth inhibition within 2 h of the addition of tyrosol, while the adhesion of yeast cells was not affected. Tyrosol increased the production of reactive oxygen species remarkably, as revealed by a dichlorofluorescein test, and it was associated with elevated superoxide dismutase, glutathione peroxidase, and catalase activities. The interaction between fluconazole and tyrosol was antagonistic. Tyrosol exposure resulted in 261 and 181 differentially expressed genes with at least a 1.5-fold increase or decrease in expression, respectively, which were selected for further study. Genes involved in ribosome biogenesis showed downregulation, while genes related to the oxidative stress response and ethanol fermentation were upregulated. In addition, tyrosol treatment upregulated the expression of efflux pump genes, including MDR1 and CDR1, and downregulated the expression of the FAD2 and FAD3 virulence genes involved in desaturated fatty acid formation. Our data demonstrate that exogenous tyrosol significantly affects the physiology and gene expression of C. parapsilosis, which could contribute to the development of treatments targeting quorum sensing in the future. IMPORTANCE Candida-secreted quorum-sensing molecules (i.e., farnesol and tyrosol) are key regulators in fungal physiology, which induce phenotypic adaptations, including morphological changes, altered biofilm formation, and synchronized expression of virulence factors. Moreover, they have a remarkable antifungal activity at supraphysiological concentrations. Limited data are available concerning the tyrosol-induced molecular and physiological effects on non-albicans Candida species such as C. parapsilosis. In addition, the background of the previously observed antifungal effect caused by tyrosol remains unknown. This study reveals that tyrosol exposure enhanced the oxidative stress response and the expression of efflux pump genes, while it inhibited growth and ribosome biogenesis as well as several virulence-related genes. Metabolism was changed toward glycolysis and ethanol fermentation. Furthermore, the initial adherence was not influenced significantly in the presence of tyrosol. Our results provide several potential explanations for the previously observed antifungal effect.

scholarly journals Necessity of OxyR for the Hydrogen Peroxide Stress Response and Full Virulence in Ralstonia solanacearum

2011 ◽  
Vol 77 (18) ◽  
pp. 6426-6432 ◽  
Author(s):  
Zomary Flores-Cruz ◽  
Caitilyn Allen
Keyword(s):  
Oxidative Stress ◽  
Gene Expression ◽  
Hydrogen Peroxide ◽  
Stress Response ◽  
Mutant Strain ◽  
Ralstonia Solanacearum ◽  
Oxidative Stress Response ◽  
Ros Scavenging ◽  
Content Type ◽  
Peroxide Stress

ABSTRACTThe plant pathogenRalstonia solanacearum, which causes bacterial wilt disease, is exposed to reactive oxygen species (ROS) during tomato infection and expresses diverse oxidative stress response (OSR) genes during midstage disease on tomato. TheR. solanacearumgenome predicts that the bacterium produces multiple and redundant ROS-scavenging enzymes but only one known oxidative stress response regulator, OxyR. AnR. solanacearumoxyRmutant had no detectable catalase activity, did not grow in the presence of 250 μM hydrogen peroxide, and grew poorly in the oxidative environment of solid rich media. This phenotype was rescued by the addition of exogenous catalase, suggesting thatoxyRis essential for the hydrogen peroxide stress response. Unexpectedly, theoxyRmutant strain grew better than the wild type in the presence of the superoxide generator paraquat. Gene expression studies indicated thatkatE,kaG,ahpC1,grxC, andoxyRitself were each differentially expressed in theoxyRmutant background and in response to hydrogen peroxide, suggesting thatoxyRis necessary for hydrogen peroxide-inducible gene expression. Additional OSR genes were differentially regulated in response to hydrogen peroxide alone. The virulence of theoxyRmutant strain was significantly reduced in both tomato and tobacco host plants, demonstrating thatR. solanacearumis exposed to inhibitory concentrations of ROSin plantaand that OxyR-mediated responses to ROS during plant pathogenesis are important forR. solanacearumhost adaptation and virulence.

scholarly journals Catalase Expression inAzospirillum brasilenseSp7 Is Regulated by a Network Consisting of OxyR and Two RpoH Paralogs and Including an RpoE1→RpoH5 Regulatory Cascade

2018 ◽  
Vol 84 (23) ◽  
Author(s):  
Ashutosh Kumar Rai ◽  
Sudhir Singh ◽  
Sushil Kumar Dwivedi ◽  
Amit Srivastava ◽  
Parul Pandey ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Stress Response ◽  
Sinorhizobium Meliloti ◽  
Deinococcus Radiodurans ◽  
Oxidative Stress Response ◽  
Sigma Factors ◽  
Transcriptional Analysis ◽  
Content Type ◽  
Regulatory Cascade ◽  
Transcription Regulators

ABSTRACTThe genome ofAzospirillum brasilenseencodes five RpoH sigma factors: two OxyR transcription regulators and three catalases. The aim of this study was to understand the role they play during oxidative stress and their regulatory interconnection. Out of the 5 paralogs of RpoH present inA. brasilense, inactivation of onlyrpoH1rendersA. brasilenseheat sensitive. While transcript levels ofrpoH1were elevated by heat stress, those ofrpoH3andrpoH5were upregulated by H2O2. Catalase activity was upregulated inA. brasilenseand itsrpoH::kmmutants in response to H2O2except in the case of therpoH5::kmmutant, suggesting a role for RpoH5 in regulating inducible catalase. Transcriptional analysis of thekatN,katAI, andkatAII genes revealed that the expression ofkatNandkatAII was severely compromised in therpoH3::kmandrpoH5::kmmutants, respectively. Regulation ofkatNandkatAII by RpoH3 and RpoH5, respectively, was further confirmed in anEscherichia colitwo-plasmid system. Regulation ofkatAII by OxyR2 was evident by a drastic reduction in growth, KatAII activity, andkatAII::lacZexpression in anoxyR2::kmmutant. This study reports the involvement of RpoH3 and RpoH5 sigma factors in regulating oxidative stress response in alphaproteobacteria. We also report the regulation of an inducible catalase by a cascade of alternative sigma factors and an OxyR. Out of the three catalases inA. brasilense, those corresponding tokatNandkatAII are regulated by RpoH3 and RpoH5, respectively. The expression ofkatAII is regulated by a cascade of RpoE1→RpoH5 and OxyR2.IMPORTANCEIn silicoanalysis of theA. brasilensegenome showed the presence of multiple paralogs of genes involved in oxidative stress response, which included 2 OxyR transcription regulators and 3 catalases. So far,Deinococcus radioduransandVibrio choleraeare known to harbor two paralogs of OxyR, andSinorhizobium melilotiharbors three catalases. We do not yet know how the expression of multiple catalases is regulated in any bacterium. Here we show the role of multiple RpoH sigma factors and OxyR in regulating the expression of multiple catalases inA. brasilenseSp7. Our work gives a glimpse of systems biology ofA. brasilenseused for responding to oxidative stress.

Calcineurin Silencing in Dictyostelium discoideum Leads to Cellular Alterations Affecting Mitochondria, Gene Expression, and Oxidative Stress Response

Protist ◽  
2018 ◽  
Vol 169 (4) ◽  
pp. 584-602 ◽  
Author(s):  
Konstanze Kobel-Höller ◽  
Kevin Gley ◽  
Janina Jochinke ◽  
Kristina Heider ◽  
Verena Nadin Fritsch ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Gene Expression ◽  
Stress Response ◽  
Dictyostelium Discoideum ◽  
Oxidative Stress Response ◽  
And Oxidative Stress ◽  
Cellular Alterations

scholarly journals Differential gene expression of granulosa cells after ovarian superstimulation in beef cattle

Reproduction ◽  
2013 ◽  
Vol 146 (2) ◽  
pp. 181-191 ◽  
Author(s):  
F C F Dias ◽  
M I R Khan ◽  
M A Sirard ◽  
G P Adams ◽  
J Singh
Keyword(s):  
Oxidative Stress ◽  
Gene Expression ◽  
Stress Response ◽  
Granulosa Cells ◽  
Rna Extraction ◽  
Oxidative Stress Response ◽  
Endoplasmic Reticulum Stress Response ◽  
Control Group ◽  
Matrix Remodeling ◽  
Upregulated Genes

Microarray analysis was used to compare the gene expression of granulosa cells from dominant follicles with that of those after superstimulatory treatment. Cows were allocated randomly to two groups (superstimulation and control, n=6/group). A new follicular wave was induced by ablation of follicles ≥5 mm in diameter, and a progesterone-releasing device controlled internal drug release (CIDR) was placed in the vagina. The superstimulation group was given eight doses of 25 mg FSH at 12-h intervals starting from the day of wave emergence (day 0), whereas the control group was not given FSH treatment. Both groups were given prostaglandin F2α twice, 12 h apart, on day 3 and the CIDR was removed at the second injection; 25 mg porcine luteinizing hormone (pLH) was given 24 h after CIDR removal, and cows were ovariectomized 24 h later. Granulosa cells were collected for RNA extraction, amplification, and microarray hybridization. A total of 190 genes were downregulated and 280 genes were upregulated. To validate the microarray results, five genes were selected for real-time PCR (NTS, FOS, THBS1, FN1, and IGF2). Expression of four genes increased significantly in the three different animals tested (NTS, FOS, THBS1, and FN1). The upregulated genes are related to matrix remodeling (i.e. tissue proliferation), disturbance of angiogenesis, apoptosis, and oxidative stress response. We conclude that superstimulation treatment i) results in granulosa cells that lag behind in maturation and differentiation (most of the upregulated genes are markers of the follicular growth stage), ii) activates genes involved with the NFE2L2 oxidative stress response and endoplasmic reticulum stress response, and iii) disturbs angiogenesis.

scholarly journals Redox-Dependent Condensation Of the Mycobacterial Nucleoid By WhiB4

2017 ◽  
Author(s):  
Manbeena Chawla ◽  
Saurabh Mishra ◽  
Pankti Parikh ◽  
Mansi Mehta ◽  
Prashant Shukla ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Gene Expression ◽  
Mycobacterium Tuberculosis ◽  
Stress Response ◽  
Redox Homeostasis ◽  
Oxidative Stress Response ◽  
Chromosomal Structure ◽  
Redox Sensor ◽  
Intracellular Redox

AbstractOxidative stress response in bacteria is generally mediated through coordination between the regulators of oxidant-remediation systems (e.g.OxyR, SoxR) and nucleoid condensation (e.g.Dps, Fis). However, these genetic factors are either absent or rendered nonfunctional in the human pathogenMycobacterium tuberculosis(Mtb). Therefore, howMtborganizes genome architecture and regulates gene expression to counterbalance oxidative imbalance during infection is not known. Here, we report that an intracellular redox-sensor, WhiB4, dynamically links genome condensation and oxidative stress response inMtb. Disruption of WhiB4 affects the expression of genes involved in maintaining redox homeostasis, central carbon metabolism (CCM), respiration, cell wall biogenesis, DNA repair and protein quality control under oxidative stress. Notably, disulfide-linked oligomerization of WhiB4 in response to oxidative stress activates the protein’s ability to condense DNAin vitroandin vivo. Further, overexpression of WhiB4 led to hypercondensation of nucleoids, redox imbalance and increased susceptibility to oxidative stress, whereas WhiB4 disruption reversed this effect. In accordance with the findingsin vitro, ChIP-Seq data demonstrated non-specific binding of WhiB4 to GC-rich regions of theMtbgenome. Lastly, data indicate that WhiB4 deletion affected the expression of only a fraction of genes preferentially bound by the protein, suggesting its indirect effect on gene expression. We propose that WhiB4 is a novel redox-dependent nucleoid condensing protein that structurally couplesMtb’sresponse to oxidative stress with genome organization and transcription.Significance StatementMycobacterium tuberculosis (Mtb)needs to adapt in response to oxidative stress encountered inside human phagocytes. In other bacteria, condensation state of nucleoids modulates gene expression to coordinate oxidative stress response. However, this relation remains elusive inMtb. We performed molecular dissection of a mechanism controlled by an intracellular redox sensor, WhiB4, in organizing both chromosomal structure and selective expression of adaptive traits to counter oxidative stress inMtb. Using high-resolution sequencing, transcriptomics, imaging, and redox biosensor, we describe how WhiB4 modulates nucleoid condensation, global gene expression, and redox-homeostasis. WhiB4 over-expression hypercondensed nucleoids and perturbed redox homeostasis whereas WhiB4 disruption had an opposite effect. Our study discovered an empirical role for WhiB4 in integrating redox signals with nucleoid condensation inMtb.

scholarly journals Rapamycin increases oxidative stress response gene expression in adult stem cells

Aging ◽  
2012 ◽  
Vol 4 (4) ◽  
pp. 279-289 ◽  
Author(s):  
Amber E. Kofman ◽  
Margeaux R. McGraw ◽  
Christopher J. Payne
Keyword(s):  
Oxidative Stress ◽  
Gene Expression ◽  
Stem Cells ◽  
Stress Response ◽  
Adult Stem Cells ◽  
Oxidative Stress Response ◽  
Response Gene ◽  
Stress Response Gene

scholarly journals Nonthermal Plasma Induces the Viable-but-Nonculturable State in Staphylococcus aureus via Metabolic Suppression and the Oxidative Stress Response

2019 ◽  
Vol 86 (5) ◽  
Author(s):  
Xinyu Liao ◽  
Donghong Liu ◽  
Tian Ding
Keyword(s):  
Oxidative Stress ◽  
Staphylococcus Aureus ◽  
Stress Response ◽  
Nonthermal Plasma ◽  
Energy Allocation ◽  
Oxidative Stress Response ◽  
Vbnc State ◽  
Viable But Nonculturable ◽  
Content Type ◽  
Energy Dependent

ABSTRACT As a novel nonthermal technology, nonthermal plasma (NTP) has attracted a lot of attention. However, it could induce microorganisms into a viable but nonculturable (VBNC) state, posing a potential risk to food safety and public health. In this study, the molecular mechanisms of VBNC Staphylococcus aureus induced by NTP were investigated. With the use of a propidium monoazide quantitative PCR (PMA-qPCR) technique combined with a plate count method, we confirmed that 8.1 to 24.3 kJ NTP induced S. aureus into a VBNC state at a level of 7.4 to 7.6 log10 CFU/ml. The transcriptomic analysis was conducted and revealed that most energy-dependent physiological activities (e.g., metabolism) were arrested in VBNC S. aureus, while the oxidative stress response-related genes (katA, dps, msrB, msrA, and trxA) were significantly upregulated. In addition, this study showed that the ATP depletion by carbonyl cyanide m-chlorophenyl hydrazone (CCCP) pretreatment could accelerate the formation of VBNC S. aureus. The NTP-generated oxidative stress triggers the staphylococcal oxidative stress response, which consumes part of cellular energy (e.g., ATP). The energy allocation is therefore changed, and the energy assigned for other energy-dependent physiological activities (cell growth and division, etc.) is reduced, subsequently forcing S. aureus into a VBNC state. Therefore, the alterations of energy allocation should be some of the major contributors to the induction of VBNC S. aureus with NTP exposure. This study provides valuable knowledge for controlling the formation of VBNC S. aureus during NTP treatment. IMPORTANCE In recent years, nonthermal plasma (NTP) technology has received a lot of attention as a promising alternative to thermal pasteurization in the food industry. However, little is known about the microbial stress response toward NTP, which could be a potential risk to food safety and impede the development of NTP. A viable but nonculturable (VBNC) state is one of the most common survival strategies employed by microorganisms against external stress. This study investigated the mechanisms of the formation of VBNC Staphylococcus aureus by NTP in a more comprehensive and systematic aspect than had been done before. Our work confirmed that the NTP-generated oxidative stress induced changes in energy allocation as a driving force for the formation of VBNC S. aureus. This study could provide better knowledge for controlling the occurrence of VBNC S. aureus induced by NTP, which could lead to more rational design and ensure the development of safe foods.

Oxidative stress response biomarker gene expression in Piaractus brachypomus (Characiformes: Serrasalmidae)

2022 ◽  
pp. 1-13
Author(s):  
Juan Sebastian Cruz-Méndez ◽  
María Paula Herrera-Sánchez ◽  
Ángel Enrique Céspedes-Rubio ◽  
Iang Schroniltgen Rondón-Barragán
Keyword(s):  
Oxidative Stress ◽  
Gene Expression ◽  
Stress Response ◽  
Oxidative Stress Response ◽  
Response Biomarker
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