scholarly journals Strategies to Better Target Fungal Squalene Monooxygenase

2021 ◽  
Vol 7 (1) ◽  
pp. 49
Author(s):  
Alia A. Sagatova
Keyword(s):  
Oxygen Atom ◽  
Human Health ◽  
Fungal Pathogens ◽  
Fungal Infections ◽  
Structural Basis ◽  
Cancer Therapies ◽  
Biosynthesis Pathway ◽  
Squalene Monooxygenase ◽  
Human Orthologue ◽  
Rate Limiting

Fungal pathogens present a challenge in medicine and agriculture. They also harm ecosystems and threaten biodiversity. The allylamine class of antimycotics targets the enzyme squalene monooxygenase. This enzyme occupies a key position in the sterol biosynthesis pathway in eukaryotes, catalyzing the rate-limiting reaction by introducing an oxygen atom to the squalene substrate converting it to 2,3-oxidosqualene. Currently, terbinafine—the most widely used allylamine—is mostly used for treating superficial fungal infections. The ability to better target this enzyme will have significant implications for human health in the treatment of fungal infections. The human orthologue can also be targeted for cholesterol-lowering therapeutics and in cancer therapies. This review will focus on the structural basis for improving the current therapeutics for fungal squalene monooxygenase.

scholarly journals Threats Posed by the Fungal Kingdom to Humans, Wildlife, and Agriculture

mBio ◽  
2020 ◽  
Vol 11 (3) ◽  
Author(s):  
Matthew C. Fisher ◽  
Sarah J. Gurr ◽  
Christina A. Cuomo ◽  
David S. Blehert ◽  
Hailing Jin ◽  
...  
Keyword(s):  
Food Security ◽  
Human Health ◽  
Fungal Pathogens ◽  
Fungal Infections ◽  
Fungal Species ◽  
Fungal Diseases ◽  
Fungal Allergy ◽  
Eukaryotic Species ◽  
Global Increase ◽  
Fungal Kingdom

ABSTRACT The fungal kingdom includes at least 6 million eukaryotic species and is remarkable with respect to its profound impact on global health, biodiversity, ecology, agriculture, manufacturing, and biomedical research. Approximately 625 fungal species have been reported to infect vertebrates, 200 of which can be human associated, either as commensals and members of our microbiome or as pathogens that cause infectious diseases. These organisms pose a growing threat to human health with the global increase in the incidence of invasive fungal infections, prevalence of fungal allergy, and the evolution of fungal pathogens resistant to some or all current classes of antifungals. More broadly, there has been an unprecedented and worldwide emergence of fungal pathogens affecting animal and plant biodiversity. Approximately 8,000 species of fungi and Oomycetes are associated with plant disease. Indeed, across agriculture, such fungal diseases of plants include new devastating epidemics of trees and jeopardize food security worldwide by causing epidemics in staple and commodity crops that feed billions. Further, ingestion of mycotoxins contributes to ill health and causes cancer. Coordinated international research efforts, enhanced technology translation, and greater policy outreach by scientists are needed to more fully understand the biology and drivers that underlie the emergence of fungal diseases and to mitigate against their impacts. Here, we focus on poignant examples of emerging fungal threats in each of three areas: human health, wildlife biodiversity, and food security.

scholarly journals Post-Translational Modifications Drive Success and Failure of Fungal–Host Interactions

2021 ◽  
Vol 7 (2) ◽  
pp. 124
Author(s):  
Charmaine Retanal ◽  
Brianna Ball ◽  
Jennifer Geddes-McAlister
Keyword(s):  
Fungal Pathogens ◽  
Fungal Infections ◽  
Treatment Options ◽  
Global Scale ◽  
Host Cells ◽  
Candida Spp ◽  
Post Translational Modifications ◽  
Fungal Host ◽  
Resistant Species

Post-translational modifications (PTMs) change the structure and function of proteins and regulate a diverse array of biological processes. Fungal pathogens rely on PTMs to modulate protein production and activity during infection, manipulate the host response, and ultimately, promote fungal survival. Given the high mortality rates of fungal infections on a global scale, along with the emergence of antifungal-resistant species, identifying new treatment options is critical. In this review, we focus on the role of PTMs (e.g., phosphorylation, acetylation, ubiquitination, glycosylation, and methylation) among the highly prevalent and medically relevant fungal pathogens, Candida spp., Aspergillus spp., and Cryptococcus spp. We explore the role of PTMs in fungal stress response and host adaptation, the use of PTMs to manipulate host cells and the immune system upon fungal invasion, and the importance of PTMs in conferring antifungal resistance. We also provide a critical view on the current knowledgebase, pose questions key to our understanding of the intricate roles of PTMs within fungal pathogens, and provide research opportunities to uncover new therapeutic strategies.

scholarly journals Antifungal Efficacy of Marine Macroalgae against Fungal Isolates from Bronchial Asthmatic Cases

Molecules ◽  
2018 ◽  
Vol 23 (11) ◽  
pp. 3032 ◽  
Author(s):  
Suresh Mickymaray ◽  
Wael Alturaiki
Keyword(s):  
Antifungal Activity ◽  
Fungal Pathogens ◽  
Fungal Infections ◽  
Algal Species ◽  
Marine Macroalgae ◽  
Minimum Fungicidal Concentration ◽  
Asthmatic Patients ◽  
The Cost ◽  
Algal Extracts ◽  
Airway Colonization

Fungal sensitization is very common in bronchial asthmatic cases, and the connection with airway colonization by fungi remains uncertain. Antifungal therapy failure is a significant fraction of the cost and morbidity and mortality in the majority of the asthmatic cases. Hence, the present study aimed to investigate the antifungal activity of five marine macroalgae—Acanthaophora specifera, Cladophoropsis sp., Laurencia paniculata, Tydemania sp., and Ulva prolifera—which were tested on selected fungal pathogens isolated from 15 sputum of 45 bronchial asthmatic patients. The highest antifungal activity was observed in ethanol fractions of L. paniculata followed by U. prolifera, Cladophoropsis sp., A. specifera, and Tydemania sp. The minimum fungicidal concentration and minimum inhibitory concentration values of the ethanolic fractions of algal species were found to be 125–1000 µg/mL and 125–500 µg/mL, respectively. The algal extracts contained terpene alcohol, diterpene, steroids, sesquiterpene, and sesquiterpene alcohol, as determined by GC–MS/MS analyses. The present study shows that the marine macroalgae containing bioactive compounds had excellent inhibitory activity against a variety of fungal pathogens, which may be useful for combating fungal infections and recovering from chronic asthmatic states.

scholarly journals Structural basis of Blastomyces Endoglucanase-2 adjuvancy in anti-fungal and -viral immunity

2021 ◽  
Vol 17 (3) ◽  
pp. e1009324
Author(s):  
Lucas dos Santos Dias ◽  
Hannah E. Dobson ◽  
Brock Kingstad Bakke ◽  
Gregory C. Kujoth ◽  
Junfeng Huang ◽  
...  
Keyword(s):  
Infectious Diseases ◽  
Influenza A ◽  
Fungal Pathogens ◽  
Animal Studies ◽  
Structural Basis ◽  
Viral Immunity ◽  
Mucosal Vaccination ◽  
Clinical Observations ◽  
Protective Antibodies ◽  
Anti Fungal

The development of safe subunit vaccines requires adjuvants that augment immunogenicity of non-replicating protein-based antigens. Current vaccines against infectious diseases preferentially induce protective antibodies driven by adjuvants such as alum. However, the contribution of antibody to host defense is limited for certain classes of infectious diseases such as fungi, whereas animal studies and clinical observations implicate cellular immunity as an essential component of the resolution of fungal pathogens. Here, we decipher the structural bases of a newly identified glycoprotein ligand of Dectin-2 with potent adjuvancy, Blastomyces endoglucanase-2 (Bl-Eng2). We also pinpoint the developmental steps of antigen-specific CD4+ and CD8+ T responses augmented by Bl-Eng2 including expansion, differentiation and tissue residency. Dectin-2 ligation led to successful systemic and mucosal vaccination against invasive fungal infection and Influenza A infection, respectively. O-linked glycans on Bl-Eng2 applied at the skin and respiratory mucosa greatly augment vaccine subunit- induced protective immunity against lethal influenza and fungal pulmonary challenge.

scholarly journals Lineage-specific selection and the evolution of virulence in the Candida clade

2021 ◽  
Vol 118 (12) ◽  
pp. e2016818118
Author(s):  
Sheena D. Singh-Babak ◽  
Tomas Babak ◽  
Hunter B. Fraser ◽  
Alexander D. Johnson
Keyword(s):  
Fungal Pathogens ◽  
Fungal Infections ◽  
Systemic Infection ◽  
Orthologous Gene ◽  
Regulatory Sequence ◽  
Mrna Levels ◽  
Evolutionary Changes ◽  
Interspecies Hybrids ◽  
Metabolism Enzymes ◽  
Evolution Of Virulence

Candida albicans is the most common cause of systemic fungal infections in humans and is considerably more virulent than its closest known relative, Candida dubliniensis. To investigate this difference, we constructed interspecies hybrids and quantified mRNA levels produced from each genome in the hybrid. This approach systematically identified expression differences in orthologous genes arising from cis-regulatory sequence changes that accumulated since the two species last shared a common ancestor, some 10 million y ago. We documented many orthologous gene-expression differences between the two species, and we pursued one striking observation: All 15 genes coding for the enzymes of glycolysis showed higher expression from the C. albicans genome than the C. dubliniensis genome in the interspecies hybrid. This pattern requires evolutionary changes to have occurred at each gene; the fact that they all act in the same direction strongly indicates lineage-specific natural selection as the underlying cause. To test whether these expression differences contribute to virulence, we created a C. dubliniensis strain in which all 15 glycolysis genes were produced at modestly elevated levels and found that this strain had significantly increased virulence in the standard mouse model of systemic infection. These results indicate that small expression differences across a deeply conserved set of metabolism enzymes can play a significant role in the evolution of virulence in fungal pathogens.

scholarly journals Sterol-response pathways mediate alkaline survival in diverse fungi

2020 ◽  
Author(s):  
Hannah E. Brown ◽  
Calla L. Telzrow ◽  
Joseph W. Saelens ◽  
Larissa Fernandes ◽  
J. Andrew Alspaugh
Keyword(s):  
Fungal Pathogens ◽  
Fungal Infections ◽  
Membrane Integrity ◽  
Microbial Pathogens ◽  
Alkaline Ph ◽  
Ph Response ◽  
Ph Tolerance ◽  
Alkaline Conditions ◽  
Host Infection ◽  
The Impact

AbstractThe ability for cells to maintain homeostasis in the presence of extracellular stress is essential for their survival. Stress adaptations are especially important for microbial pathogens to respond to rapidly changing conditions, such as those encountered during the transition from the environment to the infected host. Many fungal pathogens have acquired the ability to quickly adapt to changes in extracellular pH to promote their survival in the various micro-environments encountered during a host infection. For example, the fungal-specific Rim/Pal alkaline response pathway has been well characterized in many fungal pathogens, including Cryptococcus neoformans. However, alternative mechanisms for sensing and responding to host pH have yet to be extensively studied. Recent observations from a genetic screen suggest that the C. neoformans sterol homeostasis pathway is required for growth at elevated pH. This work explores interactions among mechanisms of membrane homeostasis, alkaline pH tolerance, and Rim pathway activation. We find that the sterol homeostasis pathway is necessary for growth in an alkaline environment, and that an elevated pH is sufficient to induce Sre1 activation. This pH-mediated activation of the Sre1 transcription factor is linked to the biosynthesis of ergosterol, but is not dependent on Rim pathway signaling, suggesting that these two pathways are responding to alkaline pH independently. Furthermore, we discover that C. neoformans is more susceptible to membrane-targeting antifungals in alkaline conditions highlighting the impact of micro-environmental pH on the treatment of invasive fungal infections. Together, these findings further connect membrane integrity and composition with the fungal pH response and pathogenesis.

scholarly journals Candida albicans Sterol C-14 Reductase, Encoded by the ERG24 Gene, as a Potential Antifungal Target Site

2002 ◽  
Vol 46 (4) ◽  
pp. 947-957 ◽  
Author(s):  
N. Jia ◽  
B. Arthington-Skaggs ◽  
W. Lee ◽  
C. A. Pierson ◽  
N. D. Lees ◽  
...  
Keyword(s):  
Candida Albicans ◽  
Fungal Pathogens ◽  
Antifungal Agents ◽  
Fungal Infections ◽  
Brefeldin A ◽  
Agricultural Applications ◽  
Mouse Model System ◽  
Cellular Inhibitors ◽  
Germ Tubes ◽  
Doubling Times

ABSTRACT The incidence of fungal infections has increased dramatically, which has necessitated additional and prolonged use of the available antifungal agents. Increased resistance to the commonly used antifungal agents, primarily the azoles, has been reported, thus necessitating the discovery and development of compounds that would be effective against the major human fungal pathogens. The sterol biosynthetic pathway has proved to be a fertile area for antifungal development, and steps which might provide good targets for novel antifungal development remain. The sterol C-14 reductase, encoded by the ERG24 gene, could be an effective target for drug development since the morpholine antifungals, inhibitors of Erg24p, have been successful in agricultural applications. The ERG24 gene of Candida albicans has been isolated by complementation of a Saccharomyces cerevisiae erg24 mutant. Both copies of the C. albicans ERG24 gene have been disrupted by using short homologous regions of the ERG24 gene flanking a selectable marker. Unlike S. cerevisiae, the C. albicans ERG24 gene was not required for growth, but erg24 mutants showed several altered phenotypes. They were demonstrated to be slowly growing, with doubling times at least twice that of the wild type. They were also shown to be significantly more sensitive to an allylamine antifungal and to selected cellular inhibitors including cycloheximide, cerulenin, fluphenazine, and brefeldin A. The erg24 mutants were also slightly resistant to the azoles. Most importantly, erg24 mutants were shown to be significantly less pathogenic in a mouse model system and failed to produce germ tubes upon incubation in human serum. On the basis of these characteristics, inhibitors of Erg24p would be effective against C. albicans.

scholarly journals Glypican-1 drives unconventional secretion of Fibroblast Growth Factor 2

2021 ◽  
Author(s):  
Carola Sparn ◽  
Eleni Dimou ◽  
Annalena Meyer ◽  
Roberto Saleppico ◽  
Sabine Wegehingel ◽  
...  
Keyword(s):  
Growth Factor ◽  
Heparan Sulfate ◽  
Fibroblast Growth Factor ◽  
Fibroblast Growth Factor 2 ◽  
Structural Basis ◽  
Limiting Factor ◽  
Fibroblast Growth ◽  
Unconventional Secretion ◽  
Rate Limiting

Fibroblast Growth Factor 2 (FGF2) is a tumor cell survival factor that is transported into the extracellular space by an unconventional secretory mechanism. Cell surface heparan sulfate proteoglycans are known to play an essential role in this process. Unexpectedly, we found that among the diverse sub-classes consisting of syndecans, perlecans, glypicans and others, Glypican-1 (GPC1) is both the principle and rate-limiting factor that drives unconventional secretion of FGF2. By contrast, we demonstrate GPC1 to be dispensable for FGF2 signaling into cells. We provide first insights into the structural basis for GPC1-dependent FGF2 secretion, identifying disaccharides with N-linked sulfate groups to be enriched in the heparan sulfate chains of GPC1 to which FGF2 binds with high affinity. Our findings have broad implications for the role of GPC1 as a key molecule in tumor progression.

Fungal Infection in Cystic Fibrosis

2021 ◽  
Vol 17 (2) ◽  
pp. 118-124
Author(s):  
Amirmehdi Sarvestani ◽  
Mohammad Almasian ◽  
Amirhossein Nafari
Keyword(s):  
Cystic Fibrosis ◽  
Fungal Infection ◽  
Fungal Pathogens ◽  
Respiratory Infections ◽  
Fungal Infections ◽  
Genetic Disorder ◽  
Medical Science ◽  
Resistant Species ◽  
Online Databases ◽  
New Treatments

Background: The prevalence of fungal infections has been increasing in recent years. Cystic fibrosis (CF) is a genetic disorder that affects organs such as the intestines, liver, pancreas, and especially the lungs. Introduction: Fungal pathogens are becoming a challenge in CF. Advanced medical science is associated with longer life expectancy in some patient groups. Method: A review was conducted on studies found on online databases, including Google Scholar, PubMed, and Scopus. Internet-based searches were performed on these databases for cystic fibrosis, respiratory infections, and fungal infection profiling to identify all relevant studies published between 2010 and 2020. Result: Fungal pathogens most frequently isolated from the respiratory tract include the Aspergillus genus, the Candida genus, Scedosporium apiospermum, and the Rasamsonia genus. In cystic fibrosis, these organisms usually colonize the respiratory and intestinal tracts and cause hypersensitivity responses and invasive diseases. Conclusion: Fungus-patient interactions are complicated and depend on various factors. Moreover, the emergence of drug-resistant species is a serious health issue, and the development of new treatments is crucial.

Identification and in Vitro Susceptibility Pattern of Fungal Pathogens in Immunocompromised Patients with invasive Fungal Infections

2021 ◽  
Vol 30 (3) ◽  
pp. 127-134
Author(s):  
Shaimaa A.S. Selem ◽  
Neveen A. Hassan ◽  
Mohamed Z. Abd El-Rahman ◽  
Doaa M. Abd El-Kareem
Keyword(s):  
Intensive Care ◽  
Fungal Infection ◽  
Fungal Pathogens ◽  
Fungal Infections ◽  
Antifungal Susceptibility ◽  
Invasive Fungal Infections ◽  
Immunocompromised Patients ◽  
University Hospitals ◽  
Vitek 2

Background: In intensive care units, invasive fungal infections have become more common, particularly among immunocompromised patients. Early identification and starting the treatment of those patients with antifungal therapy is critical for preventing unnecessary use of toxic antifungal agents. Objective: The aim of this research is to determine which common fungi cause invasive fungal infection in immunocompromised patients, as well as their antifungal susceptibility patterns in vitro, in Assiut University Hospitals. Methodology: This was a hospital based descriptive study conducted on 120 patients with clinical suspicion of having fungal infections admitted at different Intensive Care Units (ICUs) at Assiut University Hospitals. Direct microscopic examination and inoculation on Sabouraud Dextrose Agar (SDA) were performed on the collected specimens. Isolated yeasts were classified using phenotypic methods such as chromogenic media (Brilliance Candida agar), germ tube examination, and the Vitek 2 system for certain isolates, while the identification of mould isolates was primarily based on macroscopic and microscopic characteristics. Moulds were tested in vitro for antifungal susceptibility using the disc diffusion, and yeast were tested using Vitek 2 device cards. Results: In this study, 100 out of 120 (83.3%) of the samples were positive for fungal infection. Candida and Aspergillus species were the most commonly isolated fungal pathogens. The isolates had the highest sensitivity to Amphotericin B (95 %), followed by Micafungin (94 %) in an in vitro sensitivity survey. Conclusion: Invasive fungal infections are a leading cause of morbidity and mortality in immunocompromised patients, with Candida albicans being the most frequently isolated yeast from various clinical specimens; however, the rise in resistance, especially to azoles, is a major concern.

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