Antifungal activity of fused Mannich ketones triggers an oxidative stress response and is Cap1-dependent in Candida albicans.
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ABSTRACT:
SUBMITTER: Rossignol T
PROVIDER: S-EPMC3639977 | biostudies-literature | 2013
REPOSITORIES: biostudies-literature
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Antifungal activity of fused Mannich ketones triggers an oxidative stress response and is Cap1-dependent in Candida albicans.
Rossignol Tristan T Kocsis Béla B Bouquet Orsolya O Kustos Ildikó I Kilár Ferenc F Nyul Adrien A Jakus Péter B PB Rajbhandari Kshitij K Prókai László L d'Enfert Christophe C Lóránd Tamás T
PloS one 20130430 4
We investigated the antifungal activity of fused Mannich ketone (FMK) congeners and two of their aminoalcohol derivatives. In particular, FMKs with five-membered saturated rings were shown to have minimum inhibitory concentration (MIC90s) ranging from 0.8 to 6 µg/mL toward C. albicans and the closely related C. parapsilosis and C. krusei while having reduced efficacy toward C. glabrata and almost no efficacy against Aspergillus sp. Transcript profiling of C. albicans cells exposed for 30 or 60 m ...[more]
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Project description:An exponentially growing C. albicans SC5314 culture in SD medium at 30 C was split into two flasks, one exposed to MIC90 concentration of compound 2 (6.25 ug./ml-1)mannich ketones, the other to the same volume of water. Samples were collected after 30 and 60 min for transcript profiling.
2012-09-28 | E-MEXP-3534 | biostudies-arrayexpress
Project description:Cap1p, a transcription factor of the basic region-leucine zipper family, controls the oxidative stress response in Candida albicans. It was shown that alteration of the C-terminal cysteine-rich domain (CRD) of Cap1p results in nuclear retention and constitutive transcriptional activation. To further characterize the function of Cap1p in C. albicans, we used genome-wide location profiling (ChIP-on-chip), allowing the identification of Cap1p-transcriptional targets in vivo. Location profiling using a tiled-oligonucleotide DNA microarray identified 89 targets that were bound by Cap1p-HA3 or Cap1p-CSE-HA3 (binding ratio ≥ 2-fold, P ≤ 0.01). Strikingly, Cap1p binding was not only detected at the promoter region of its target genes but also at their 3'-end and within their open-reading frame. Overrepresented functional groups of Cap1p targets (P ≤ 0.02) included notably 11 genes involved in response to oxidative stress (CAP1, GLR1, TRX1, others), 13 genes involved in response to drug (PDR16, MDR1, FLU1, others) and 3 genes involved in regulation of nitrogen utilization (orf19.2693, orf19.3121 and GST3). Bioinformatic analyses suggested that Cap1p binds to the DNA motif 5'- MTKASTMA. Transcriptome analyses showed that increased expression of most of Cap1p targets accompanies Cap1p binding at these targets, indicating that Cap1p is a transcriptional activator. We conclude that, in addition to protecting the cell against oxidative stress, Cap1p appears to have other functions including drug resistance and the regulation of nitrogen utilization. The atypical binding pattern of Cap1p suggests that this transcription factor may associate with the transcriptional or the chromatin remodeling machinery to exert its activity.
2009-06-22 | GSE14258 | GEO
Project description:UnlabelledFollowing phagocytosis, microbes are exposed to an array of antimicrobial weapons that include reactive oxygen species (ROS) and cationic fluxes. This is significant as combinations of oxidative and cationic stresses are much more potent than the corresponding single stresses, triggering the synergistic killing of the fungal pathogenCandida albicansby "stress pathway interference." Previously we demonstrated that combinatorial oxidative plus cationic stress triggers a dramatic increase in intracellular ROS levels compared to oxidative stress alone. Here we show that activation of Cap1, the major regulator of antioxidant gene expression inC. albicans, is significantly delayed in response to combinatorial stress treatments and to high levels of H2O2 Cap1 is normally oxidized in response to H2O2; this masks the nuclear export sequence, resulting in the rapid nuclear accumulation of Cap1 and the induction of Cap1-dependent genes. Here we demonstrate that following exposure of cells to combinatorial stress or to high levels of H2O2, Cap1 becomes trapped in a partially oxidized form, Cap1(OX-1) Notably, Cap1-dependent gene expression is not induced when Cap1 is in this partially oxidized form. However, while Cap1(OX-1)readily accumulates in the nucleus and binds to target genes following high-H2O2stress, the nuclear accumulation of Cap1(OX-1)following combinatorial H2O2and NaCl stress is delayed due to a cationic stress-enhanced interaction with the Crm1 nuclear export factor. These findings define novel mechanisms that delay activation of the Cap1 transcription factor, thus preventing the rapid activation of the stress responses vital for the survival ofC. albicanswithin the host.ImportanceCombinatorial stress-mediated synergistic killing represents a new unchartered area in the field of stress signaling. This phenomenon contrasts starkly with "stress cross-protection," where exposure to one stress protects against subsequent exposure to a different stress. Previously we demonstrated that the pathogenCandida albicansis acutely sensitive to combinations of cationic and oxidative stresses, because the induction of H2O2-responsive genes is blocked in the presence of cationic stress. We reveal that this is due to novel mechanisms that delay activation of the Cap1 AP-1-like transcription factor, the major regulator of the H2O2-induced regulon. Cap1 becomes trapped in a partially oxidized form following simultaneous exposure to oxidative and cationic stresses. In addition, cationic stress promotes the interaction of Cap1 with the Crm1 nuclear export factor, thus inhibiting its nuclear accumulation. These mechanisms probably explain the potency of neutrophils, which employ multiple stresses to kill fungal pathogens.
| S-EPMC4817257 | biostudies-literature
Project description:Candida albicans, a ubiquitous opportunistic fungal pathogen, plays a pivotal role in human health and disease. As a commensal organism, it normally resides harmlessly within the human microbiota. However, under certain conditions, C. albicans can transition into a pathogenic state, leading to various infections collectively known as candidiasis. With the increasing prevalence of immunocompromised individuals and the widespread use of invasive medical procedures, candidiasis has become a significant public health concern. The emergence of drug-resistant strains further complicates treatment options, highlighting the urgent need for alternative therapeutic strategies. Antifungal peptides (AFPs) have gained considerable attention as potential candidates for combating Candida spp. infections. These naturally occurring peptides possess broad-spectrum antimicrobial activity, including specific efficacy against C. albicans. AFPs exhibit several advantageous properties, such as rapid killing kinetics, low propensity for resistance development, and diverse mechanisms of action, making them promising alternatives to conventional antifungal agents. In recent years, extensive research has focused on discovering and developing novel AFPs with improved efficacy and selectivity against Candida species. Advances in biotechnology and synthetic peptide design have enabled the modification and optimization of natural peptides, enhancing their stability, bioavailability, and therapeutic potential. Nevertheless, several challenges must be addressed before AFPs can be widely implemented in clinical practice. These include optimizing peptide stability, enhancing delivery methods, overcoming potential toxicity concerns, and conducting comprehensive preclinical and clinical studies. This commentary presents a short overview of candidemia and AFP; articles and reviews published in the last 10 years were searched on The National Library of Medicine (National Center for Biotechnology Information-NIH-PubMed). The terms used were C. albicans infections, antimicrobial peptides, antifungal peptides, antifungal peptides mechanisms of action, candidemia treatments and guidelines, synthetic peptides and their challenges, and antimicrobial peptides in clinical trials as the main ones. Older publications were cited if they brought some relevant concept or helped to bring a perspective into our narrative. Articles older than 20 years and those that appeared in PubMed but did not match our goal to bring updated information about using antifungal peptides as an alternative to C. albicans infections were not considered.
| S-EPMC10746669 | biostudies-literature
Project description:Cap1p, a transcription factor of the basic region-leucine zipper family, regulates oxidative stress response (OSR) in Candida albicans. Alteration of its C-terminal cysteine-rich domain (CRD) results in Cap1p nuclear retention and transcriptional activation. To better understand the function of Cap1p in C. albicans, we used genome-wide location profiling (ChIP-on-chip) to identify its transcriptional targets in vivo. A triple-hemagglutinin epitope was introduced at the C-terminus of wild-type Cap1p (Cap1p-HA3) or hyperactive Cap1p with an altered CRD (Cap1p-CSE-HA3). Location profiling using whole-genome oligonucleotide tiling microarrays identified 89 targets bound by Cap1p-HA3 or Cap1p-CSE-HA3 (binding ratio ≥ 2-fold, P ≤ 0.01). Strikingly, Cap1p binding was not only detected at the promoter region of its target genes but also at their 3'-end and within their open-reading frame, suggesting that Cap1p may associate with the transcriptional or the chromatin remodeling machinery to exert its activity. Overrepresented functional groups of the Cap1p targets (P ≤ 0.02) included 11 genes involved in OSR (CAP1, GLR1, TRX1, SOD1, CAT1, others), 13 genes involved in response to drugs (PDR16, MDR1, FLU1, YCF1, FCR1, others), 4 genes involved in phospholipid transport (PDR16, GIT1, RTA2, orf19.932) and 3 genes involved in the regulation of nitrogen utilization (GST3, orf19.2693, orf19.3121), suggesting that Cap1p has other cellular functions in addition to OSR. Bioinformatic analyses of the bound sequences suggest that Cap1p recognizes the DNA motif 5'- MTKASTMA. Finally, transcriptome analyses showed that increased expression generally accompanies Cap1p binding at its targets, indicating that Cap1p functions as a transcriptional activator.
2009-06-22 | GSE15104 | GEO
Project description:Cap1p, a transcription factor of the basic region-leucine zipper family, controls the oxidative stress response in Candida albicans. It was shown that alteration of the C-terminal cysteine-rich domain (CRD) of Cap1p results in nuclear retention and constitutive transcriptional activation. To further characterize the function of Cap1p in C. albicans, we used genome-wide location profiling (ChIP-on-chip), allowing the identification of Cap1p-transcriptional targets in vivo. Location profiling using a tiled-oligonucleotide DNA microarray identified 89 targets that were bound by Cap1p-HA3 or Cap1p-CSE-HA3 (binding ratio ⥠2-fold, P ⤠0.01). Strikingly, Cap1p binding was not only detected at the promoter region of its target genes but also at their 3'-end and within their open-reading frame. Overrepresented functional groups of Cap1p targets (P ⤠0.02) included notably 11 genes involved in response to oxidative stress (CAP1, GLR1, TRX1, others), 13 genes involved in response to drug (PDR16, MDR1, FLU1, others) and 3 genes involved in regulation of nitrogen utilization (orf19.2693, orf19.3121 and GST3). Bioinformatic analyses suggested that Cap1p binds to the DNA motif 5'- MTKASTMA. Transcriptome analyses showed that increased expression of most of Cap1p targets accompanies Cap1p binding at these targets, indicating that Cap1p is a transcriptional activator. We conclude that, in addition to protecting the cell against oxidative stress, Cap1p appears to have other functions including drug resistance and the regulation of nitrogen utilization. The atypical binding pattern of Cap1p suggests that this transcription factor may associate with the transcriptional or the chromatin remodeling machinery to exert its activity. We performed three gene expression profile comparisons: (1) benomyl-induced gene expression in a strain containing wildtype CAP1 (CJD21/PMK-CAP1 +/- benomyl), (2) benomyl-induced gene expression in a strain where CAP1 is disrupted (CJD21/PMK +/- benomyl), and (3) gene expression in a strain containing a hyperactive allele of CAP1 compared to a strain containing wildtype CAP1 (CJD21/PMK-CAP1-CSE vs. CJD21/PMK-CAP1). There were three biological replicates (each drug-treated and untreated strain was grown/treated in three independent experiments). Since our Affymetrix platform requires each sample is hybridized on a separate chip, there is no dye-swapping. For each benomyl-treatment experiment (comparisons 1 and 2 above), the untreated (diluent-treated) samples are the reference samples. For comparison 3, the CJD21-PMK-CAP1 sample is the reference sample.
2010-05-18 | E-GEOD-14258 | biostudies-arrayexpress
Project description:Mannich bases and its derivatives are regarded as supreme pharmacophores in therapeutics. The study investigates the antimycotic potential of Mannich bases, 1-((1H-benzimidazol-1-yl) methyl) urea (C1) and 1-((3-hydroxynapthalen-2-yl) methyl) thiourea (C2), against Candida albicans. Biofilm and hyphal inhibitory activities of the Mannich bases were tested by crystal violet quantification, fluorescence imaging cAMP rescue, qRT PCR, and by molecular docking analysis. The compounds inhibited the biofilms of C. albicans and restrained the filamentation abilities of the pathogen. Structure-activity relationship studies revealed that the presence of urea or thiourea moiety in the tail section is essential for interacting with adenylate cyclase (AC). The Mannich bases seemed to block Ras-cAMP-PKA pathway by inhibiting second messenger activity required for hyphal induction and biofilm formation. In conclusion, the study warrants point-of-care testing of C1/C2 and provides a starting point for deriving several structurally modified Mannich bases which might plausibly replace the prevailing antimycotic drugs in future.
| S-EPMC6175908 | biostudies-literature
Project description:The fungal pathogen Candida albicans causes lethal systemic infections in humans. To better define how pathogens resist oxidative attack by the immune system, we examined a family of four Flavodoxin-Like Proteins (FLPs) in C. albicans. In agreement with previous studies showing that FLPs in bacteria and plants act as NAD(P)H quinone oxidoreductases, a C. albicans quadruple mutant lacking all four FLPs (pst1?, pst2?, pst3?, ycp4?) was more sensitive to benzoquinone. Interestingly, the quadruple mutant was also more sensitive to a variety of oxidants. Quinone reductase activity confers important antioxidant effects because resistance to oxidation was restored in the quadruple mutant by expressing either Escherichia coli wrbA or mammalian NQO1, two distinct types of quinone reductases. FLPs were detected at the plasma membrane in C. albicans, and the quadruple mutant was more sensitive to linolenic acid, a polyunsaturated fatty acid that can auto-oxidize and promote lipid peroxidation. These observations suggested that FLPs reduce ubiquinone (coenzyme Q), enabling it to serve as an antioxidant in the membrane. In support of this, a C. albicans coq3? mutant that fails to synthesize ubiquinone was also highly sensitive to oxidative stress. FLPs are critical for survival in the host, as the quadruple mutant was avirulent in a mouse model of systemic candidiasis under conditions where infection with wild type C. albicans was lethal. The quadruple mutant cells initially grew well in kidneys, the major site of C. albicans growth in mice, but then declined after the influx of neutrophils and by day 4 post-infection 33% of the mice cleared the infection. Thus, FLPs and ubiquinone are important new antioxidant mechanisms that are critical for fungal virulence. The potential of FLPs as novel targets for antifungal therapy is further underscored by their absence in mammalian cells.
| S-EPMC4556627 | biostudies-literature
Project description:The major fungal pathogen of humans, Candida albicans, mounts robust responses to oxidative stress that are critical for its virulence. These responses counteract the reactive oxygen species (ROS) that are generated by host immune cells in an attempt to kill the invading fungus. Knowledge of the dynamical processes that instigate C. albicans oxidative stress responses is required for a proper understanding of fungus-host interactions. Therefore, we have adopted an interdisciplinary approach to explore the dynamical responses of C. albicans to hydrogen peroxide (H2O2). Our deterministic mathematical model integrates two major oxidative stress signalling pathways (Cap1 and Hog1 pathways) with the three major antioxidant systems (catalase, glutathione and thioredoxin systems) and the pentose phosphate pathway, which provides reducing equivalents required for oxidative stress adaptation. The model encapsulates existing knowledge of these systems with new genomic, proteomic, transcriptomic, molecular and cellular datasets. Our integrative approach predicts the existence of alternative states for the key regulators Cap1 and Hog1, thereby suggesting novel regulatory behaviours during oxidative stress. The model reproduces both existing and new experimental observations under a variety of scenarios. Time- and dose-dependent predictions of the oxidative stress responses for both wild type and mutant cells have highlighted the different temporal contributions of the various antioxidant systems during oxidative stress adaptation, indicating that catalase plays a critical role immediately following stress imposition. This is the first model to encapsulate the dynamics of the transcriptional response alongside the redox kinetics of the major antioxidant systems during H2O2 stress in C. albicans.
| S-EPMC4569071 | biostudies-literature
Project description:Candida albicans is a commensal that inhabits the skin and mucous membranes of humans. Because of the increasing immunocompromised population and the limited classes of antifungal drugs available, C. albicans has emerged as an important opportunistic pathogen with high mortality rates. During infection and therapy, C. albicans frequently encounters immune cells and antifungal drugs, many of which exert their antimicrobial activity by inducing the production of reactive oxygen species (ROS). Therefore, antioxidative capacity is important for the survival and pathogenesis of C. albicans. In this study, we characterized the roles of the zinc finger transcription factor Sfp1 in the oxidative stress response against C. albicans. A sfp1-deleted mutant was more resistant to oxidants and macrophage killing than wild-type C. albicans and processed an active oxidative stress response with the phosphorylation of the mitogen-activated protein kinase (MAPK) Hog1 and high CAP1 expression. Moreover, the sfp1-deleted mutant exhibited high expression levels of antioxidant genes in response to oxidative stress, resulting in a higher total antioxidant capacity, glutathione content, and glutathione peroxidase and superoxide dismutase enzyme activity than the wild-type C. albicans. Finally, the sfp1-deleted mutant was resistant to macrophage killing and ROS-generating antifungal drugs. Together, our findings provide a new understanding of the complex regulatory machinery in the C. albicans oxidative stress response.
| S-EPMC6560436 | biostudies-literature