scholarly journals Metamorphic Protein Folding Encodes Multiple Anti-Candida Mechanisms in XCL1

Pathogens ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 762
Author(s):  
Acacia F. Dishman ◽  
Jie He ◽  
Brian F. Volkman ◽  
Anna R. Huppler
Keyword(s):  
Antifungal Drugs ◽  
Surrounding Tissue ◽  
Membrane Disruption ◽  
Antimicrobial Proteins ◽  
Iodide Uptake ◽  
Future Design ◽  
Serious Infections ◽  
Metamorphic Protein ◽  
Folded Structures ◽  
Adenylate Kinase Release

Candida species cause serious infections requiring prolonged and sometimes toxic therapy. Antimicrobial proteins, such as chemokines, hold great interest as potential additions to the small number of available antifungal drugs. Metamorphic proteins reversibly switch between multiple different folded structures. XCL1 is a metamorphic, antimicrobial chemokine that interconverts between the conserved chemokine fold (an α–β monomer) and an alternate fold (an all-β dimer). Previous work has shown that human XCL1 kills C. albicans but has not assessed whether one or both XCL1 folds perform this activity. Here, we use structurally locked engineered XCL1 variants and Candida killing assays, adenylate kinase release assays, and propidium iodide uptake assays to demonstrate that both XCL1 folds kill Candida, but they do so via different mechanisms. Our results suggest that the alternate fold kills via membrane disruption, consistent with previous work, and the chemokine fold does not. XCL1 fold-switching thus provides a mechanism to regulate the XCL1 mode of antifungal killing, which could protect surrounding tissue from damage associated with fungal membrane disruption and could allow XCL1 to overcome candidal resistance by switching folds. This work provides inspiration for the future design of switchable, multifunctional antifungal therapeutics.

scholarly journals Synthetic Peptide ΔM4-Induced Cell Death Associated with Cytoplasmic Membrane Disruption, Mitochondrial Dysfunction and Cell Cycle Arrest in Human Melanoma Cells

Molecules ◽  
2020 ◽  
Vol 25 (23) ◽  
pp. 5684
Author(s):  
Gloria A. Santa-González ◽  
Edwin Patiño-González ◽  
Marcela Manrique-Moreno
Keyword(s):  
Cell Cycle ◽  
Skin Cancer ◽  
Anticancer Agents ◽  
Synthetic Peptide ◽  
Melanoma Cells ◽  
Human Melanoma ◽  
Membrane Disruption ◽  
Iodide Uptake ◽  
Human Melanoma Cells ◽  
Wide Range

Melanoma is the most dangerous and lethal form of skin cancer, due to its ability to spread to different organs if it is not treated at an early stage. Conventional chemotherapeutics are failing as a result of drug resistance and weak tumor selectivity. Therefore, efforts to evaluate novel molecules for the treatment of skin cancer are necessary. Antimicrobial peptides have become attractive anticancer agents because they execute their biological activity with features such as a high potency of action, a wide range of targets, and high target specificity and selectivity. In the present study, the antiproliferative activity of the synthetic peptide ΔM4 on A375 human melanoma cells and spontaneously immortalized HaCaT human keratinocytes was investigated. The cytotoxic effect of ΔM4 treatment was evaluated through propidium iodide uptake by flow cytometry. The results indicated selective toxicity in A375 cells and, in order to further investigate the mode of action, assays were carried out to evaluate morphological changes, mitochondrial function, and cell cycle progression. The findings indicated that ΔM4 exerts its antitumoral effects by multitarget action, causing cell membrane disruption, a change in the mitochondrial transmembrane potential, an increase of reactive oxygen species, and cell cycle accumulation in S-phase. Further exploration of the peptide may be helpful in the design of novel anticancer peptides.

scholarly journals Structure, Mechanism, and Inhibition of Aspergillus fumigatus Thioredoxin Reductase

2019 ◽  
Vol 63 (3) ◽  
Author(s):  
Andrew C. Marshall ◽  
Sarah E. Kidd ◽  
Stephanie J. Lamont-Friedrich ◽  
Georgia Arentz ◽  
Peter Hoffmann ◽  
...  
Keyword(s):  
Aspergillus Fumigatus ◽  
Enzyme Inhibitor ◽  
Redox Homeostasis ◽  
Thioredoxin Reductase ◽  
Antifungal Drugs ◽  
Mass Spectrometry Analysis ◽  
Content Type ◽  
Spectrometry Analysis ◽  
Future Design

ABSTRACT Aspergillus fumigatus infections are associated with high mortality rates and high treatment costs. Limited available antifungals and increasing antifungal resistance highlight an urgent need for new antifungals. Thioredoxin reductase (TrxR) is essential for maintaining redox homeostasis and presents as a promising target for novel antifungals. We show that ebselen [2-phenyl-1,2-benzoselenazol-3(2H)-one] is an inhibitor of A. fumigatus TrxR (Ki = 0.22 μM) and inhibits growth of Aspergillus spp., with in vitro MIC values of 16 to 64 µg/ml. Mass spectrometry analysis demonstrates that ebselen interacts covalently with a catalytic cysteine of TrxR, Cys148. We also present the X-ray crystal structure of A. fumigatus TrxR and use in silico modeling of the enzyme-inhibitor complex to outline key molecular interactions. This provides a scaffold for future design of potent and selective antifungal drugs that target TrxR, improving the potency of ebselen toward inhbition of A. fumigatus growth.

scholarly journals Characterization, Biological Activity, and Mechanism of Action of a Plant-Based Novel Antifungal Peptide, Cc-AFP1, Isolated From Carum carvi

2021 ◽  
Vol 11 ◽  
Author(s):  
Sima Sadat Seyedjavadi ◽  
Soghra Khani ◽  
Mehdi Goudarzi ◽  
Hadi Zare-Zardini ◽  
Masoomeh Shams-Ghahfarokhi ◽  
...  
Keyword(s):  
Antifungal Activity ◽  
Sequence Analysis ◽  
Fungal Infections ◽  
Reversed Phase ◽  
Antifungal Drugs ◽  
Peptide Sequence ◽  
Cell Membrane Permeability ◽  
Iodide Uptake ◽  
Fungal Cell ◽  
Carum Carvi

Due to the increasing rate of invasive fungal infections and emerging antifungal resistance, development of novel antifungal drugs has been an urgent necessity. Antifungal peptides (AFPs) have recently attracted attention due to their unique ability to evade drug-resistant fungal pathogens. In this study, a novel AFP, Cc-AFP1, with a molecular weight of ~3.759 kDa, was isolated from Carum carvi L., purified by ammonium sulfate precipitation and reversed-phase HPLC and finally identified by sequence analysis using Edman degradation. Peptide sequence analysis revealed a fragment of 36 amino acid residues as RVCFRPVAPYLGVGVSGAVRDQIGVKLGSVYKGPRG for Cc-AFP1 with a net charge of +5 and a hydrophobicity ratio of 38%. The antifungal activity of Cc-AFP1 was confirmed against Aspergillus species with MIC values in the range of 8–16 µg/ml. Cc-AFP1 had less than 5% hemolytic activity at 8–16 µg/ml on human red blood cells with no obvious cytotoxicity against the HEK293 cell line. Stability analysis showed that the activity of Cc-AFP1 was maintained at different temperatures (20°C to 80°C) and pH (8 to 10). The results of a propidium iodide uptake and transmission electron microscopy showed that the antifungal activity of Cc-AFP1 could be attributed to alteration in the fungal cell membrane permeability. Taken together, these results indicate that Cc-AFP1 may be an attractive molecule to develop as a novel antifungal agent combating fungal infections cause by Aspergillus species.

Tissue section lifting for electron microscopy

1978 ◽  
Vol 36 (2) ◽  
pp. 86-87
Author(s):  
Adrian F. van Dellen
Keyword(s):  
Infectious Disease ◽  
Electron Microscopy ◽  
Tissue Culture ◽  
Organ System ◽  
Surrounding Tissue ◽  
Paraffin Sections ◽  
Surface Areas ◽  
Specific Determination ◽  
High Degree ◽  
Accuracy And Repeatability

The morphologic pathologist may require information on the ultrastructure of a non-specific lesion seen under the light microscope before he can make a specific determination. Such lesions, when caused by infectious disease agents, may be sparsely distributed in any organ system. Tissue culture systems, too, may only have widely dispersed foci suitable for ultrastructural study. In these situations, when only a few, small foci in large tissue areas are useful for electron microscopy, it is advantageous to employ a methodology which rapidly selects a single tissue focus that is expected to yield beneficial ultrastructural data from amongst the surrounding tissue. This is in essence what "LIFTING" accomplishes. We have developed LIFTING to a high degree of accuracy and repeatability utilizing the Microlift (Fig 1), and have successfully applied it to tissue culture monolayers, histologic paraffin sections, and tissue blocks with large surface areas that had been initially fixed for either light or electron microscopy.

Some quantitative applications of vascular corrosion casting

1992 ◽  
Vol 50 (1) ◽  
pp. 738-739
Author(s):  
Fred E. Hossler
Keyword(s):  
Blood Vessels ◽  
Nuclear Orientation ◽  
Three Dimensional ◽  
Surrounding Tissue ◽  
Confocal Laser ◽  
Corrosion Casting ◽  
Venous Valve ◽  
Casting Technique ◽  
Low Viscosity ◽  
Quantitative Measurements

Preparation of replicas of the complex arrangement of blood vessels in various organs and tissues has been accomplished by infusing low viscosity resins into the vasculature. Subsequent removal of the surrounding tissue by maceration leaves a model of the intricate three-dimensional anatomy of the blood vessels of the tissue not obtainable by any other procedure. When applied with care, the vascular corrosion casting technique can reveal fine details of the microvasculature including endothelial nuclear orientation and distribution (Fig. 1), locations of arteriolar sphincters (Fig. 2), venous valve anatomy (Fig. 3), and vessel size, density, and branching patterns. Because casts faithfully replicate tissue vasculature, they can be used for quantitative measurements of that vasculature. The purpose of this report is to summarize and highlight some quantitative applications of vascular corrosion casting. In each example, casts were prepared by infusing Mercox, a methyl-methacrylate resin, and macerating the tissue with 20% KOH. Casts were either mounted for conventional scanning electron microscopy, or sliced for viewing with a confocal laser microscope.

Hepatocyte ultrastructural alterations in perimetastatic areas

1996 ◽  
Vol 54 ◽  
pp. 768-769
Author(s):  
H. J. Finol ◽  
M. E. Correa ◽  
L.A. Sosa ◽  
A. Márquez ◽  
N.L. Díaz
Keyword(s):  
Malignant Tumor ◽  
Malignant Tumors ◽  
Surrounding Tissue ◽  
Ultrastructural Changes ◽  
Pancreas Carcinoma ◽  
Duct Carcinoma ◽  
Tissue Samples ◽  
Primary Malignant Tumor ◽  
Transmission Electron ◽  
Remote Sites

In classical oncological literature two mechanisms for tissue aggression in patients with cancer have been described. The first is the progressive invasion, infiltration and destruction of tissues surrounding primary malignant tumor or their metastases; the other includes alterations produced in remote sites that are not directly affected by any focus of disease, the so called paraneoplastic phenomenon. The non-invaded tissue which surrounds a primary malignant tumor or its metastases has been usually considered a normal tissue . In this work we describe the ultrastructural changes observed in hepatocytes located next to metastases from diverse malignant tumors.Hepatic biopsies were obtained surgically in patients with different malignant tumors which metatastized in liver. Biopsies included tumor mass, the zone of macroscopic contact between the tumor and the surrounding tissue, and the tissue adjacent to the tumor but outside the macroscopic area of infiltration. The patients (n = 5), 36–75 years old, presented different tumors including rhabdomyosarcoma, leiomyosarcoma, pancreas carcinoma, biliar duct carcinoma and colon carcinoma. Tissue samples were processed with routine techniques for transmission electron microscopy and observed in a Hitachi H-500 electron microscope.

ITI with high-dose FIX and combined immunosuppressive therapy in a patient with severe haemophilia B and inhibitor

2009 ◽  
Vol 29 (02) ◽  
pp. 155-157 ◽  
Author(s):  
H. Hauch ◽  
J. Rischewski ◽  
U. Kordes ◽  
J. Schneppenheim ◽  
R. Schneppenheim ◽  
...  
Keyword(s):  
Nephrotic Syndrome ◽  
Immunosuppressive Agents ◽  
Tolerance Induction ◽  
Intravenous Immunoglobulins ◽  
Factor Ix ◽  
High Dose ◽  
Allergic Reactions ◽  
Success Rates ◽  
Serious Infections ◽  
History Of

SummaryInhibitor development is a rare but serious event in hemophilia B patients. Management is hampered by the frequent occurrence of allergic reactions to factor IX, low success rates of current inhibitor elimination protocols and the risk of development of nephrotic syndrome. Single cases of immune tolerance induction (ITI) including immunosuppressive agents like mycophenolat mofetil (MMF) or rituximab have been reported. We present a case of successful inhibitor elimination with a combined immune-modulating therapy and high-dose factor IX (FIX). This boy had developed a FIX inhibitor at the age of 5 years and had a history of allergic reactions to FIX and to FEIBA→. Under on-demand treatment with recombinant activated FVII the inhibitor became undetectable but the boy suffered from multiple joint and muscle bleeds. At the age of 11.5 years ITI was attempted with a combination of rituximab, MMF, dexamethasone, intravenous immunoglobulins and high-dose FIX. The inhibitor did not reappear and FIX half-life normalized. No allergic reaction, no signs of nephrotic syndrome and no serious infections were observed.

The role of WNT5A in tumor and tumor surrounding tissue in primary and metastatic prostate cancer

2020 ◽  
Author(s):  
W Kisel ◽  
S Conrad ◽  
S Füssel ◽  
U Sommer ◽  
GB Baretton ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Metastatic Prostate Cancer ◽  
Surrounding Tissue
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