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PloS One 2024Humans have approximately 400 different olfactory receptors (hORs) and recognize odorants through the repertoire of hOR responses. Although the cell surface expression...
Humans have approximately 400 different olfactory receptors (hORs) and recognize odorants through the repertoire of hOR responses. Although the cell surface expression of hORs is critical to evaluate their response, hORs are poorly expressed on the surface of heterologous cells. To address this problem, previous studies have focused on hOR transportation to the membrane. Nevertheless, the response pattern of hORs to odorants has yet to be successfully linked, and the response sensitivity still remains to be improved. In this study, we demonstrate that increasing the transcriptional level can result in a significant increase in cell surface and functional expression of hORs. We used the TAR-Tat system, which increases the transcription efficiency through positive feedback, and found that OR1A1, OR6N2, and OR51M1 exhibited robust expression. Moreover, this system induces enhanced hOR responses to odorants, thus defining four hORs as novel n-hexanal receptors and n-hexanal is an inverse agonist to one of them. Our results suggested that using the TAR-Tat system and increasing the transcriptional level of hORs can help understanding the relationship between hORs and odorants that were previously undetectable. This finding could facilitate the understanding of the sense of smell by decoding the repertoire of hOR responses.
Topics: Receptors, Odorant; Humans; Transcription, Genetic; Odorants; Aldehydes
PubMed: 38917199
DOI: 10.1371/journal.pone.0306029 -
MBio Jun 2024causes cryptococcosis, one of the most prevalent fungal diseases, generally characterized by meningitis. There is a limited and not very effective number of drugs...
UNLABELLED
causes cryptococcosis, one of the most prevalent fungal diseases, generally characterized by meningitis. There is a limited and not very effective number of drugs available to combat this disease. In this manuscript, we show the host defense peptide mimetic brilacidin (BRI) as a promising antifungal drug against . BRI can affect the organization of the cell membrane, increasing the fungal cell permeability. We also investigated the effects of BRI against the model system by analyzing libraries of mutants grown in the presence of BRI. In , BRI also affects the cell membrane organization, but in addition the cell wall integrity pathway and calcium metabolism. experiments show BRI significantly reduces survival inside macrophages and partially clears lung infection in an immunocompetent murine model of invasive pulmonary cryptococcosis. We also observed that BRI interacts with caspofungin (CAS) and amphotericin (AmB), potentiating their mechanism of action against . BRI + CAS affects endocytic movement, calcineurin, and mitogen-activated protein kinases. Our results indicate that BRI is a novel antifungal drug against cryptococcosis.
IMPORTANCE
Invasive fungal infections have a high mortality rate causing more deaths annually than tuberculosis or malaria. Cryptococcosis, one of the most prevalent fungal diseases, is generally characterized by meningitis and is mainly caused by two closely related species of basidiomycetous yeasts, and . There are few therapeutic options for treating cryptococcosis, and searching for new antifungal agents against this disease is very important. Here, we present brilacidin (BRI) as a potential antifungal agent against . BRI is a small molecule host defense peptide mimetic that has previously exhibited broad-spectrum immunomodulatory/anti-inflammatory activity against bacteria and viruses. BRI alone was shown to inhibit the growth of , acting as a fungicidal drug, but surprisingly also potentiated the activity of caspofungin (CAS) against this species. We investigated the mechanism of action of BRI and BRI + CAS against . We propose BRI as a new antifungal agent against cryptococcosis.
PubMed: 38916308
DOI: 10.1128/mbio.01031-24 -
Drugs in Context 2024Invasive fungal infections (IFIs) are important infectious complications amongst critically ill children. The most common fungal infections are due to species. , and... (Review)
Review
BACKGROUND
Invasive fungal infections (IFIs) are important infectious complications amongst critically ill children. The most common fungal infections are due to species. , and are also emerging because of the empirical use of antifungal drugs. This updated review discusses the epidemiology of IFIs as well as antifungal drugs, dosing and potential adverse effects in critically ill children.
METHODS
A PubMed search was conducted with Clinical Queries using the key terms "antifungal", "children", "critical care" AND "paediatric intensive care unit" OR "PICU". The search strategy included clinical trials, randomized controlled trials, meta-analyses, observational studies and reviews and was limited to the English literature in paediatrics.
RESULTS
and spp. are the most prevalent fungi in paediatric IFIs, causing invasive candidiasis infections (ICIs) and invasive aspergillosis infections (IAIs), respectively. These IFIs are associated with high morbidity, mortality and healthcare costs. is the principal spp. associated with paediatric ICIs. The risks and epidemiology for IFIs vary if considering previously healthy children treated in the paediatric intensive care unit or children with leukaemia, malignancy or a severe haematological disease. The mortality rate for IAIs in children is 2.5-3.5-fold higher than for ICIs. Four major classes of antifungals for critically ill children are azoles, polyenes, antifungal antimetabolites and echinocandins.
CONCLUSIONS
Antifungal agents are highly efficacious. For successful treatment outcomes, it is crucial to determine the optimal dosage, monitor pharmacokinetics parameters and adverse effects, and individualized therapeutic monitoring. Despite potent antifungal medications, ICIs and IAIs continue to be serious infections with high mortality rates. Pre-emptive therapy has been used for IAIs. Most guidelines recommend voriconazole as initial therapy of invasive aspergillosis in most patients, with consideration of combination therapy with voriconazole plus an echinocandin in selected patients with severe disease. The challenge is to identify critically ill patients at high risks of ICIs for targeted prophylaxis. Intravenous/per os fluconazole is first-line pre-emptive treatment for spp. whereas intravenous micafungin or intravenous liposomal amphotericin B is alternative pre-emptive treatment.This article is part of the Special Issue: https://www.drugsincontext.com/special_issues/challenges-and-strategies-in-the-management-of-invasive-fungal-infections.
PubMed: 38915918
DOI: 10.7573/dic.2023-9-2 -
Frontiers in Microbiology 2024head blight (FHB) is a destructive disease caused by several species of , such as and . FHB affects cereal crops, including wheat, barley, and rice, worldwide....
head blight (FHB) is a destructive disease caused by several species of , such as and . FHB affects cereal crops, including wheat, barley, and rice, worldwide. -infected kernels not only cause reduced yields but also cause quality loss by producing mycotoxins, such as trichothecenes and zearalenone, which are toxic to animals and humans. For decades, chemical fungicides have been used to control FHB because of their convenience and high control efficacy. However, the prolonged use of chemical fungicides has caused adverse effects, including the emergence of drug resistance to pathogens and environmental pollution. Biological control is considered one of the most promising alternatives to chemicals and can be used for integrated management of FHB due to the rare possibility of environment pollution and reduced health risks. In this study, JCK-7158 isolated from rice was selected as an ecofriendly alternative to chemical fungicides for the management of FHB. JCK-7158 produced the extracellular enzymes protease, chitinase, gelatinase, and cellulase; the plant growth hormone indole-3-acetic acid; and the 2,3-butanediol precursor acetoin. Moreover, JCK-7158 exhibited broad antagonistic activity against various phytopathogenic fungi and produced iturin A, surfactin, and volatile substances as active antifungal compounds. It also enhanced the expression of , a known induced resistance marker gene, in transgenic plants expressing β-glucuronidase (GUS) fused with the promoter. Under greenhouse conditions, treatments with the culture broth and suspension concentrate formulation of JCK-7158 at a 1,000-fold dilution inhibited the development of FHB by 50 and 66%, respectively. In a field experiment, treatment with the suspension concentrate formulation of JCK7158 at a 1,000-fold dilution effectively controlled the development of FHB with a control value of 55% and reduced the production of the mycotoxin nivalenol by 40%. Interestingly, treatment with JCK-7158 enhanced the expression of plant defense-related genes in salicylic acid, jasmonic acid, ethylene, and reactive oxygen species (ROS) signaling pathways before and after FHB pathogen inoculation. Taken together, our findings support that JCK-7158 has the potential to serve as a new biocontrol agent for the management of FHB.
PubMed: 38915299
DOI: 10.3389/fmicb.2024.1358689 -
Scientific Reports Jun 2024Azole antifungal drugs are commonly used to treat vulvovaginal candidiasis (VVC). The nephrotoxicity and developmental toxicity of azole drugs have not been...
Azole antifungal drugs are commonly used to treat vulvovaginal candidiasis (VVC). The nephrotoxicity and developmental toxicity of azole drugs have not been systematically analyzed in the real world. We used the FDA Adverse Event Reporting System (FAERS) to investigate the adverse events (AEs) associated with imidazole therapy for VVC. FAERS data (from quarter 1 2004 to quarter 3 2022) were retrieved using OpenVigil 2.1, and AEs were retrieved and standardized according to the Medical Dictionary for Regulatory Activities (MedDRA). In the top 10 System Organ Class (SOC), all four drugs have been found to have kidney and urinary system diseases and pregnancy. We found significant signals, including clotrimazole [bladder transitional cell carcinoma, (report odds ratio, ROR = 291.66)], [fetal death, (ROR = 10.28)], ketoconazole[nephrogenic anemia (ROR = 22.1)], [premature rupture of membranes (ROR = 22.91 46.45, 11, 3)], Miconazole[hematuria (ROR = 19.03)], [neonatal sepsis (ROR = 123.71)], [spontaneous abortion (ROR = 5.98)], Econazole [acute kidney injury (ROR = 4.41)], [spontaneous abortion (ROR = 19.62)]. We also discovered new adverse reactions that were not reported. Therefore, when using imidazole drugs for treatment, it is necessary to closely monitor the patient's renal function, pay attention to the developmental toxicity of the fetus during pregnancy, and be aware of potential adverse reactions that may occur.
Topics: Female; Humans; Candidiasis, Vulvovaginal; Antifungal Agents; Imidazoles; United States; United States Food and Drug Administration; Adverse Drug Reaction Reporting Systems; Pregnancy; Adult; Drug-Related Side Effects and Adverse Reactions; Miconazole; Clotrimazole
PubMed: 38914572
DOI: 10.1038/s41598-024-63315-1 -
Microbiology Spectrum Jun 2024is a life-threatening fungal pathogen that is a causative agent for pulmonary infection and meningoencephalitis in both immunocompetent and immunodeficient individuals....
UNLABELLED
is a life-threatening fungal pathogen that is a causative agent for pulmonary infection and meningoencephalitis in both immunocompetent and immunodeficient individuals. Recent studies have elucidated the important function of the target of rapamycin (TOR) signaling pathway in the modulation of virulence factor production and pathogenicity in animal infection models. Herein, we discovered that Ypk1, a critical component of the TOR signaling pathway, acts as a critical modulator in fungal pathogenicity through post-translational modifications (PTMs). Mass spectrometry analysis revealed that Ypk1 is subject to protein acetylation at lysines 315 and 502, and both sites are located within kinase functional domains. Inhibition of the TOR pathway by rapamycin activates the deacetylation process for Ypk1. The strain, a hyper-acetylation of Ypk1, exhibited increased sensitivity to rapamycin, decreased capsule formation ability, reduced starvation tolerance, and diminished fungal pathogenicity, indicating that deacetylation of Ypk1 is crucial for responding to stress. Deacetylase inhibition assays have shown that sirtuin family proteins are critical to the Ypk1 deacetylation mechanism. After screening deacetylase mutants, we found that Dac1 and Dac7 directly interact with Ypk1 to facilitate the deacetylation modification process via a protein-protein interaction. These findings provide new insights into the molecular basis for regulating the TORC-Ypk1 axis and demonstrate an important function of protein acetylation in modulating fungal pathogenicity.
IMPORTANCE
is an important opportunistic fungal pathogen in humans. While there are currently few effective antifungal treatments, the absence of novel molecular targets in fungal pathogenicity hinders the development of new drugs. There is increasing evidence that protein post-translational modifications (PTMs) can modulate the pathogenicity of fungi. In this study, we discovered that the pathogenicity of was significantly impacted by the dynamic acetylation changes of Ypk1, the immediate downstream target of the TOR complex. We discovered that Ypk1 is acetylated at lysines 315 and 502, both of which are within kinase functional domains. Deacetylation of Ypk1 is necessary for formation of the capsule structure, the response to the TOR pathway inhibitor rapamycin, nutrient utilization, and host infection. We also demonstrate that the sirtuin protein family is involved in the Ypk1 deacetylation mechanism. We anticipate that the sirtuin-Ypk1 regulation axis could be used as a potential target for the development of antifungal medications.
PubMed: 38912819
DOI: 10.1128/spectrum.00038-24 -
Frontiers in Cellular and Infection... 2024Invasive mold diseases of the central nervous (CNS IMD) system are exceedingly rare disorders, characterized by nonspecific clinical symptoms. This results in...
BACKGROUND
Invasive mold diseases of the central nervous (CNS IMD) system are exceedingly rare disorders, characterized by nonspecific clinical symptoms. This results in significant diagnostic challenges, often leading to delayed diagnosis and the risk of misdiagnosis for patients. Metagenomic Next-Generation Sequencing (mNGS) holds significant importance for the diagnosis of infectious diseases, especially in the rapid and accurate identification of rare and difficult-to-culture pathogens. Therefore, this study aims to explore the clinical characteristics of invasive mold disease of CNS IMD in children and assess the effectiveness of mNGS technology in diagnosing CNS IMD.
METHODS
Three pediatric patients diagnosed with Invasive mold disease brain abscess and treated in the Pediatric Intensive Care Unit (PICU) of the First Affiliated Hospital of Zhengzhou University from January 2020 to December 2023 were selected for this study.
RESULTS
Case 1, a 6-year-old girl, was admitted to the hospital with "acute liver failure." During her hospital stay, she developed fever, irritability, and seizures. CSF mNGS testing resulted in a negative outcome. Multiple brain abscesses were drained, and was detected in pus culture and mNGS. The condition gradually improved after treatment with voriconazole combined with caspofungin. Case 2, a 3-year-old girl, was admitted with "acute B-lymphoblastic leukemia." During induction chemotherapy, she developed fever and seizures. was detected in the intracranial abscess fluid by mNGS, and the condition gradually improved after treatment with voriconazole combined with caspofungin, followed by "right-sided brain abscess drainage surgery." Case 3, a 7-year-old girl, showed lethargy, fever, and right-sided limb weakness during the pending chemotherapy period for acute B-lymphoblastic leukemia. and was detected in the cerebrospinal fluid by mNGS. The condition gradually improved after treatment with amphotericin B combined with posaconazole. After a six-month follow-up post-discharge, the three patients improved without residual neurological sequelae, and the primary diseases were in complete remission.
CONCLUSION
The clinical manifestations of CNS IMD lack specificity. Early mNGS can assist in identifying the pathogen, providing a basis for definitive diagnosis. Combined surgical treatment when necessary can help improve prognosis.
Topics: Humans; Female; High-Throughput Nucleotide Sequencing; Child; Metagenomics; Brain Abscess; Antifungal Agents; Invasive Fungal Infections; Male; Central Nervous System Fungal Infections; Child, Preschool; Aspergillus fumigatus; Caspofungin
PubMed: 38912204
DOI: 10.3389/fcimb.2024.1393242 -
Clinical Case Reports Jul 2024In addition to post-transplant lymphoproliferative disorders, it is necessary to be alert to the drug-resistant bacteria or fungal infection, especially , in kidney...
KEY CLINICAL MESSAGE
In addition to post-transplant lymphoproliferative disorders, it is necessary to be alert to the drug-resistant bacteria or fungal infection, especially , in kidney transplant patients who have failed antibiotic treatment and whose PET-CT indicates high metabolic mass in the transplanted kidney with a large number of other organs and lymph nodes.
ABSTRACT
(TM) is a rare pathogenic fungus that primarily affects individuals with compromised immune systems. Post-transplant lymphoproliferative disorders (PTLD) are serious complications that can occur after solid organ and cell transplantation. Both TM infection and PTLD can invade the monocyte-macrophage system and often manifest as extranodal masses. This case report describes a kidney transplant patient who presented with symptoms of frequent, urgent, and painful urination over 6 months. Pulmonary CT scans revealed multiple nodules, and PET-CT demonstrated enlarged lymph nodes in the lungs and the transplanted kidney. The clinical manifestations closely mimicked those of PTLD. The confirmation of TM was achieved through pathogen metagenomic next-generation sequencing and renal biopsy. Unfortunately, despite receiving treatment with antifungal agents, anti-infective therapy, the patient's condition did not respond favorably, ultimately resulting in their unfortunate demise due to COVID-19.
PubMed: 38911919
DOI: 10.1002/ccr3.9028 -
Journal of Nanobiotechnology Jun 2024Recently, environmental temperature has been shown to regulate bone homeostasis. However, the mechanisms by which cold exposure affects bone mass remain unclear. In our...
Recently, environmental temperature has been shown to regulate bone homeostasis. However, the mechanisms by which cold exposure affects bone mass remain unclear. In our present study, we observed that exposure to cold temperature (CT) decreased bone mass and quality in mice. Furthermore, a transplant of exosomes derived from the plasma of mice exposed to cold temperature (CT-EXO) can also impair the osteogenic differentiation of BMSCs and decrease bone mass by inhibiting autophagic activity. Rapamycin, a potent inducer of autophagy, can reverse cold exposure or CT-EXO-induced bone loss. Microarray sequencing revealed that cold exposure increases the miR-25-3p level in CT-EXO. Mechanistic studies showed that miR-25-3p can inhibit the osteogenic differentiation and autophagic activity of BMSCs. It is shown that inhibition of exosomes release or downregulation of miR-25-3p level can suppress CT-induced bone loss. This study identifies that CT-EXO mediates CT-induced osteoporotic effects through miR-25-3p by inhibiting autophagy via targeting SATB2, presenting a novel mechanism underlying the effect of cold temperature on bone mass.
Topics: Animals; Autophagy; Mice; Exosomes; MicroRNAs; Cold Temperature; Osteogenesis; Mice, Inbred C57BL; Mesenchymal Stem Cells; Osteoporosis; Cell Differentiation; Bone and Bones; Female; Bone Density; Sirolimus
PubMed: 38910236
DOI: 10.1186/s12951-024-02640-z -
Scientific Reports Jun 2024Frequent and variant infections are caused by the virtue of opportunistic fungi pathogens. Candidiasis, aspergillosis, and mucormycosis are pathogenic microorganisms...
Frequent and variant infections are caused by the virtue of opportunistic fungi pathogens. Candidiasis, aspergillosis, and mucormycosis are pathogenic microorganisms that give rise to vast fungal diseases that alternate between moderate to fatal in severity. The use of fluconazole as an antifungal drug was limited due to the acquired resistance in some types of Candida and other fungal species. This study aims to consolidate fluconazole's biological effectiveness against several pathogenic fungi. Six active monoterpenes (MTs) of carvacrol, linalool, geraniol, α-terpinene, citronellal, and nerolidol were selected and encapsulated in nanostructure lipid carrier (NLC) with (NLC-Flu-MTs) and/without (NLC-MTs) fluconazole in one nanoformulation to determine if they will act synergistically or not? The synthesized nanoformulation NLC-Flu-MTs and NLC-MTs exhibited very good particle size of 144.5 nm and 138.6 nm for size and zeta potential values of (- 23.5 mV) and (- 20.3 mV), respectively. Transmission electron microscope investigation confirmed that the synthesized NLCs have regular and spherical shape. The abundance and concentration of the six released monoterpenes were determined, as a novel approach, using GC-MS with very good results and validity. In-vitro antifungal screening was done before and after nano co-delivery against seven pathogenic, and aggressive fungi of Candida tropicalis, Candida krusei, Candida glabrata, Geotrichum Candidum, Candidaalbicans, Aspergillus Niger, and mucor circinelloides. Inhibition Zone diameter (IZD) and the minimum inhibitory concentration (MIC) were measured. Nanoformulations NLC-Flu-MTs and NLC-MTs manifested potential and unique biological susceptibility against all the tested microorganisms with reduced (MIC) values, especially against Candida Tropicalis (MIC = 0.97 µg/ml) which represents 16-fold of the value shown by NLC-MTs (MIC = 15.6 µg/ml) and 64-fold of fluconazole free before nanoformulation (MIC = 62.5 µg/ml). The efficiency of nanomaterials, particularly NLC-Flu-MTs, has become evident in the diminishing value of MIC which affirmed the synergism between fluconazole and the other six monoterpenes.
Topics: Antifungal Agents; Fluconazole; Microbial Sensitivity Tests; Monoterpenes; Nanostructures; Lipids; Drug Synergism; Drug Carriers; Particle Size; Candida
PubMed: 38909063
DOI: 10.1038/s41598-024-63149-x