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Candida auris has emerged as a significant healthcare-associated pathogen due to its multidrug-resistant nature. Ongoing constraints in the discovery and provision of new antifungals create an urgent imperative to design effective remedies to this pressing global blight. Herein, we screened a chemical library and identified aryl-carbohydrazide analogs with potent activity against both C. auris and the most prevalent human fungal pathogen, C. albicans . SPB00525 [ N '-(2,6-dichlorophenyl)-5-nitro-furan-2-carbohydrazide] exhibited potent activity against different strains that were resistant to standard antifungals. Using drug-induced haploinsufficient profiling, transcriptomics and metabolomic analysis, we uncovered that Ole1, a Δ(9) fatty acid desaturase, is the likely target of SPB00525. An analog of the latter, HTS06170 [ N '-(2,6-dichlorophenyl)-4-methyl-1,2,3-thiadiazole-5-carbohydrazide], had a superior antifungal activity against both C. auris and C. albicans . Both SPB00525 and HTS06170 act as antivirulence agents and inhibited the invasive hyphal growth and biofilm formation of C. albicans . SPB00525 and HTS06170 attenuated fungal damage to human enterocytes and ameliorate the survival of Galleria mellonella larvae used as systemic candidiasis model. These data suggest that inhibiting fungal Δ(9) fatty acid desaturase activity represents a potential therapeutic approach for treating fungal infection caused by the superbug C. auris and the most prevalent human fungal pathogen, C. albicans ., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest. The author(s) declared that they were an editorial board member of Frontiers, at the time of submission. This had no impact on the peer review process and the final decision., (Copyright © 2024 Tebbji, Menon, Khemiri, St-Cyr, Villeneuve, Vincent and Sellam.)

Due to the scarcity of transition metals within the human host, fungal pathogens have evolved sophisticated mechanisms to uptake and utilize these micronutrients at the infection interface. While considerable attention was turned to iron and copper acquisition mechanisms and their importance in fungal fitness, less was done regarding either the role of manganese (Mn) in infectious processes or the cellular mechanism by which fungal cells achieve their Mn-homeostasis. Here, we undertook transcriptional profiling in the pathogenic fungus Candida albicans experiencing both Mn starvation and excess to capture biological processes that are modulated by this metal. We uncovered that Mn scarcity influences diverse processes associated with fungal fitness including invasion of host cells and antifungal sensitivity. We show that Mn levels influence the abundance of iron and zinc emphasizing the complex crosstalk between metals. The deletion of SMF12 , a member of Mn Nramp transporters, confirmed its contribution to Mn uptake. smf12 was unable to form hyphae and damage host cells and exhibited sensitivity to azoles. We found that the unfolded protein response (UPR), likely activated by decreased glycosylation under Mn limitation, was required to recover growth when cells were shifted from an Mn-starved to an Mn-repleted medium. RNA-seq profiling of cells exposed to Mn excess revealed that UPR was also activated. Furthermore, the UPR signaling axis Ire1-Hac1 was required to bypass Mn toxicity. Collectively, this study underscores the importance of Mn homeostasis in fungal virulence and comprehensively provides a portrait of biological functions that are modulated by Mn in a fungal pathogen., Importance: Transition metals such as manganese provide considerable functionality across biological systems as they are used as cofactors for many catalytic enzymes. The availability of manganese is very limited inside the human body. Consequently, pathogenic microbes have evolved sophisticated mechanisms to uptake this micronutrient inside the human host to sustain their growth and cause infections. Here, we undertook a comprehensive approach to understand how manganese availability impacts the biology of the prevalent fungal pathogen, Candida albicans . We uncovered that manganese homeostasis in this pathogen modulates different biological processes that are essential for host infection which underscores the value of targeting fungal manganese homeostasis for potential antifungal therapeutics development., Competing Interests: The authors declare no conflict of interest.

Candida albicans is a human colonizer and also an opportunistic yeast occupying different niches that are mostly hypoxic. While hypoxia is the prevalent condition within the host, the machinery that integrates oxygen status to tune the fitness of fungal pathogens remains poorly characterized. Here, we uncovered that Snf5, a subunit of the chromatin remodeling complex SWI/SNF, is required to tolerate antifungal stress particularly under hypoxia. RNA-seq profiling of snf5 mutant exposed to amphotericin B and fluconazole under hypoxic conditions uncovered a signature that is reminiscent of copper (Cu) starvation. We found that under hypoxic and Cu-starved environments, Snf5 is critical for preserving Cu homeostasis and the transcriptional modulation of the Cu regulon. Furthermore, snf5 exhibits elevated levels of reactive oxygen species and an increased sensitivity to oxidative stress principally under hypoxia. Supplementing growth medium with Cu or increasing gene dosage of the Cu transporter CTR1 alleviated snf5 growth defect and attenuated reactive oxygen species levels in response to antifungal challenge. Genetic interaction analysis suggests that Snf5 and the bona fide Cu homeostasis regulator Mac1 function in separate pathways. Together, our data underlined a unique role of SWI/SNF complex as a potent regulator of Cu metabolism and antifungal stress under hypoxia., (© The Author(s) 2024. Published by Oxford University Press on behalf of FEMS.)

Objectives: This study aimed to investigate the effect of the n-butanol fraction of the methanol leaf extract of Artemisia campestris (BFAC), growing wild in the arid zone of Tunisia, on induced obesity in male Wistar rats., Methods: The total phenolic content and antioxidant capacity of the BFAC were estimated. The main phenolic composition of the BFAC was determined using the high-performance chromatography system coupled with a diode array detector technics. Five groups of rats received either a standard diet (SD group), a high-fat diet (HFD group), or an HFD supplemented with oral administration of BFAC for eight weeks., Results: The BFAC showed higher phenolic content and antioxidant potential than the total leaf methanol extract. Chlorogenic acid, rutin, and dicaffeoylquinic acids were identified in the BFAC. HFD increased body and relative liver weights, as well as serum and hepatic levels of triglycerides and total cholesterol, compared to SD. HFD generated significant oxidative stress in the liver by increasing lipid peroxidation and reducing glutathione-S-transferase, catalase, and glutathione peroxidase activities, compared to SD. These HFD-altered parameters were restored to normal values by oral treatment with the BFAC., Conclusions: These findings give first evidence about the antiobesity efficacy of A. campestris . Such a study would enhance existing information and promote the use of this species., (© 2022 Walter de Gruyter GmbH, Berlin/Boston.)

To persist in their dynamic human host environments, fungal pathogens must sense and adapt by modulating their gene expression to fulfill their cellular needs. Understanding transcriptional regulation on a global scale would uncover cellular processes linked to persistence and virulence mechanisms that could be targeted for antifungal therapeutics. Infections associated with the yeast Candida albicans , a highly prevalent fungal pathogen, and the multiresistant related species Candida auris are becoming a serious public health threat. To define the set of a gene regulated by a transcriptional regulator in C. albicans , chromatin immunoprecipitation (ChIP)-based techniques, including ChIP with microarray technology (ChIP-chip) or ChIP-DNA sequencing (ChIP-seq), have been widely used. Here, we describe a new set of PCR-based micrococcal nuclease (MNase)-tagging plasmids for C. albicans and other Candida spp. to determine the genome-wide location of any transcriptional regulator of interest using chromatin endogenous cleavage (ChEC) coupled to high-throughput sequencing (ChEC-seq). The ChEC procedure does not require protein-DNA cross-linking or sonication, thus avoiding artifacts related to epitope masking or the hyper-ChIPable euchromatic phenomenon. In a proof-of-concept application of ChEC-seq, we provided a high-resolution binding map of the SWI/SNF chromatin remodeling complex, a master regulator of fungal fitness in C. albicans , in addition to the transcription factor Nsi1 that is an ortholog of the DNA-binding protein Reb1 for which genome-wide occupancy was previously established in Saccharomyces cerevisiae The ChEC-seq procedure described here will allow a high-resolution genomic location definition which will enable a better understanding of transcriptional regulatory circuits that govern fungal fitness and drug resistance in these medically important fungi. IMPORTANCE Systemic fungal infections caused by Candida albicans and the "superbug" Candida auris are becoming a serious public health threat. The ability of these yeasts to cause disease is linked to their faculty to modulate the expression of genes that mediate their escape from the immune surveillance and their persistence in the different unfavorable niches within the host. Comprehensive knowledge on gene expression control of fungal fitness is consequently an interesting framework for the identification of essential infection processes that could be hindered by chemicals as potential therapeutics. Here, we expanded the use of ChEC-seq, a technique that was initially developed in the yeast model Saccharomyces cerevisiae to identify genes that are modulated by a transcriptional regulator, in pathogenic yeasts from the genus Candida This robust technique will allow a better characterization of key gene expression regulators and their contribution to virulence and antifungal resistance in these pathogenic yeasts., (Copyright © 2020 Tebbji et al.)

Copper homeostasis is an important determinant for virulence of many human pathogenic fungi such as the highly prevalent yeast Candida albicans . However, beyond the copper transporter Ctr1, little is known regarding other genes and biological processes that are affected by copper. To gain insight into the cellular processes that are modulated by copper abundance in C. albicans , we monitored the global gene expression dynamic under both copper depletion and excess using RNA-seq. Beyond copper metabolism, other different transcriptional programs related to fungal fitness such as stress responses, antifungal sensitivity, host invasion and commensalism were modulated in response to copper variations. We have also investigated the transcriptome of the mutant of the copper utilization regulator, mac1 , and identified potential direct targets of this transcription factor under copper starvation. We also showed that Mac1 was required for the invasion and adhesion to host cells and antifungal tolerance. This study provides a framework for future studies to examine the link between copper metabolism and essential functions that modulate fungal virulence and fitness inside the host., (Copyright © 2020 Khemiri, Tebbji and Sellam.)

Hypoxia is the predominant condition that the human opportunistic fungus Candida albicans encounters in the majority of the colonized niches within the host. So far, the impact of such a condition on the overall metabolism of this important human-pathogenic yeast has not been investigated. Here, we have undertaken a time-resolved metabolomics analysis to uncover the metabolic landscape of fungal cells experiencing hypoxia. Our data showed a dynamic reprogramming of many fundamental metabolic pathways, such as glycolysis, the pentose phosphate pathway, and different metabolic routes related to fungal cell wall biogenesis. The C. albicans lipidome was highly affected by oxygen depletion, with an increased level of free fatty acids and biochemical intermediates of membrane lipids, including phospholipids, lysophospholipids, sphingolipids, and mevalonate. The depletion of oxygen-dependent lipids such as ergosterol or phosphatidylcholine with longer and polyunsaturated lateral fatty acid chains was observed only at the later hypoxic time point (180 min). Transcriptomics data supported the main metabolic response to hypoxia when matched to our metabolomic profiles. The hypoxic metabolome reflected different physiological alterations of the cell wall and plasma membrane of C. albicans under an oxygen-limiting environment that were confirmed by different approaches. This study provided a framework for future in vivo investigations to examine relevant hypoxic metabolic trajectories in fungal virulence and fitness within the host. IMPORTANCE A critical aspect of cell fitness is the ability to sense and adapt to variations in oxygen levels in their local environment. Candida albicans is an opportunistic yeast that is the most prevalent human fungal pathogen. While hypoxia is the predominant condition that C. albicans encounters in most of its niches, its impact on fungal metabolism remains unexplored so far. Here, we provided a detailed landscape of the C. albicans metabolome that emphasized the importance of many metabolic routes for the adaptation of this yeast to oxygen depletion. The fungal hypoxic metabolome identified in this work provides a framework for future investigations to assess the contribution of relevant metabolic pathways in the fitness of C. albicans and other human eukaryotic pathogens with similar colonized human niches. As hypoxia is present at most of the fungal infection foci in the host, hypoxic metabolic pathways are thus an attractive target for antifungal therapy., (Copyright © 2020 Burgain et al.)

Context: Vitis vinifera leaves are traditionally used in Tunisian folk medicine to treat digestive pathologies. Objective: We aimed to compare the gastroprotective effects of hydromethanolic leaves extracts of wild and cultivated grapes accessions native of Tunisia. Materials and methods: Pre-treatment with grapevine leaves extracts decreased significantly gastric volume, gastric mucosal damage and increased significantly gastric juice pH compared with the negative control group. The extracts prevented ethanol-induced decrease of the activity of antioxidant enzymes while the levels of malondialdehyde and of reduced glutathione were decreased significantly. Moreover, the most marked effect was observed at low doses of wild ecotype 'Nefza-I' extracts. Results: Pre-treatment with grapevine leaves extracts decreased significantly gastric volume, gastric mucosal damage and increased significantly gastric juice pH compared with the negative control group. The extracts prevented ethanol-induced decrease of the activity of antioxidant enzymes while the levels of malondialdehyde and of reduced glutathione were decreased significantly. Moreover, the most marked effect was observed at low doses of wild ecotype 'Nefza-I' extracts. Conclusion: species might be suitable as a functional food for therapeutic purpose and demonstrates gastroprotective action in gastric lesions model. Both accessions exhibited gastroprotective effects, but wild 'Nefza-I' ecotype was more effective than cultivar 'Marsaoui'.Vitis species might be suitable as a functional food for therapeutic purpose and demonstrates gastroprotective action in gastric lesions model. Both accessions exhibited gastroprotective effects, but wild 'Nefza-I' ecotype was more effective than cultivar 'Marsaoui'.

Background and Objectives: A lot of research has been directed towards medicinal plants which are considered as a source of multiple phytotherapic substances endowed with hypoglycemic activities that could be used to treat diabetes and its complications. Our study was carried out in Wistar rats to investigate the hypoglycemic effect of n-Butanol Fraction from Artemisia campestris leaf Methanolic Extract (BFACME)., Methods: Two experimental models were used in rats: orally induced hyperglycemia (OGTT) and isolated perfused liver (IPRL)., Results: BFACME at 550 mg/kg BW dose significantly reduced fasting glucose level in normal rats as compared to controls. The decrease of glycaemia was 12.6% more significant than that obtained with the standard drug glibenclamide (10 mg/kg BW), an oral antidiabetic preparation belonging to sulfonylurea class. In OGTT model, BFACME at the highest doses of 550 and 400 mg/kg BW significantly reduced the postprandial hyperglycemic peak compared to controls. In the IPRL model, treatment with BFACME significantly decreased glucose concentrations after 30 min of perfusion with 30 mM glucose solely when insulin was present. The higher doses of BFACME lead to glucose concentration at basal level as early as 90 min, while the lowest dose does not restore this concentration even to t = 120min. The best initial glucose concentration retrieval was obtained with 0.7 mg BFACME/mL/g liver. At this dose, BFACME improves the decrease of glucose level caused by only insulin by about 18%., Conclusion: The BFACME appears to exert a hypoglycemic activity by potentiating the insulin action., (© 2019 Belgacem et al.)

Purpose: The purpose of this study was to assess the feasibility, efficacy and toxicity of fiducial marker implantation and tracking in CyberKnife® stereotactic radiation therapy (SBRT) applied to extracranial locations., Materials and Method: This is a retrospective, single-centre, observational study to collect the data of all patients treated by stereotactic radiation therapy with fiducial marker tracking at extracranial locations, conducted between June 2014 and November 2017. Information regarding the implantation procedure, the types of toxicity related to marker implantation and the number of markers implanted/tracked during treatment were collected. Complication rates were evaluated using the CTCAE v4 [Common Terminology Criteria for Adverse Events] scale. The technical success rate was based on the ability to optimally track the tumor throughout all treatment fractions., Results: Out of 2505 patients treated by stereotactic radiation therapy, 25% received treatment with fiducial marker tracking. The total number of implantation procedures was 616 and 1543 fiducial markers were implanted. The implantation-related complication rate was 3%, with 16 Grade 1 events and 4 Grade 2 events. The number of treated patients and the number of implanted markers has gradually increased since the technique was first implemented. The median treatment time was 27 min (range 10-76). 1295 fiducials were effectively tracked throughout all treatment fractions, corresponding to a technical success rate of 84%. The difference between the number of fiducials implanted and those tracked during treatment decreased significantly as the site's experience increased., Conclusion: Fiducial marker implantation and tracking is feasible, well-tolerated, and technically effective technique in SBRT for extracranial tumors.

Most cells spend the majority of their life in a non-proliferating state. When proliferation cessation is irreversible, cells are senescent. By contrast, if the arrest is only temporary, cells are defined as quiescent. These cellular states are hardly distinguishable without triggering proliferation resumption, hampering thus the study of quiescent cells properties. Here we show that quiescent and senescent yeast cells are recognizable based on their mitochondrial network morphology. Indeed, while quiescent yeast cells display numerous small vesicular mitochondria, senescent cells exhibit few globular mitochondria. This allowed us to reconsider at the individual-cell level, properties previously attributed to quiescent cells using population-based approaches. We demonstrate that cell's propensity to enter quiescence is not influenced by replicative age, volume or density. Overall, our findings reveal that quiescent cells are not all identical but that their ability to survive is significantly improved when they exhibit the specific reorganization of several cellular machineries., Competing Interests: DL, LG, LJ, IK, IS No competing interests declared, (© 2018, Laporte et al.)

A poorly exploited paradigm in the antimicrobial therapy field is to target virulence traits for drug development. In contrast to target-focused approaches, antivirulence phenotypic screens enable identification of bioactive molecules that induce a desirable biological readout without making a priori assumption about the cellular target. Here, we screened a chemical library of 678 small molecules against the invasive hyphal growth of the human opportunistic yeast Candida albicans. We found that a halogenated salicylanilide (N1-(3,5-dichlorophenyl)-5-chloro-2-hydroxybenzamide) and one of its analogs, Niclosamide, an FDA-approved anthelmintic in humans, exhibited both antifilamentation and antibiofilm activities against C. albicans and the multi-resistant yeast C. auris. The antivirulence activity of halogenated salicylanilides were also expanded to C. albicans resistant strains with different resistance mechanisms. We also found that Niclosamide protected the intestinal epithelial cells against invasion by C. albicans. Transcriptional profiling of C. albicans challenged with Niclosamide exhibited a signature that is characteristic of the mitochondria-to-nucleus retrograde response. Our chemogenomic analysis showed that halogenated salicylanilides compromise the potential-dependant mitochondrial protein translocon machinery. Given the fact that the safety of Niclosamide is well established in humans, this molecule could represent the first clinically approved antivirulence agent against a pathogenic fungus.

In this study, phycocyanin (Pc) extracted from Spirulina platensis was used to evaluate its antioxidants effects after ischemia/reperfusion injury (IRI) using the ex-vivo model of isolated perfused rat liver. The rats were divided into eight groups : Control group, where livers were directly perfused after their removal; Cold Ischemia group (CI), livers were treated in the same way as the control group, except that after their collection, they were stored for 12 h and 24 h in the Krebs Henseleit (KH) preservation solution at 4 °C and Treated group (PHY), livers were preserved in the same way as the preceding group except that the KH solution was enriched with phycocyanin at two different concentrations. Pc, a powerful antioxidant, significantly reduced ischemia/reperfusion injury in the liver. In fact, the addition of phycocyanin to the preservation solution significantly decreased the activity of liver transaminases (AST) and (ALT), alkaline phosphatase (ALP), the rate of lipid peroxidation (MDA) and the activity of certain antioxidant enzymes, essentially glutathione-S-transferase (GST) and glutathione peroxidase (GPx). On the other hand, Pc increases the level of thiol groups in hepatic tissues. In conclusion, the results show the Pc-enriched KH conservation solution is effective in preserving the hepatic graft and protecting it against IRI by acting as a potent antioxidant against the products of oxidative stress., (Published by Elsevier Masson SAS.)