Integrated Omics Approach to Unveil Antifungal Bacterial Polyynes as acetyl-CoA Acetyltransferase Inhibitors

Author(s):  
Ching-Chih Lin ◽  
Sin Yong Hoo ◽  
Li-Ting Ma ◽  
Chih Lin ◽  
Kai-Fa Huang ◽  
...  

Abstract Bacterial polyynes are highly active natural products with a broad spectrum of antimicrobial activities. However, their detailed mechanism of action remains unclear. By integrating comparative genomics, transcriptomics, functional genetics, and metabolomics analysis, we identified a unique polyyne resistance gene, masL (encoding acetyl-CoA acetyltransferase), in the biosynthesis gene cluster of antifungal polyynes (massilin A 1, massilin B 2, collimonin C 3, and collimonin D 4) of Massilia sp. YMA4. Crystallographic analysis indicated that bacterial polyynes serve as covalent inhibitors of acetyl-CoA acetyltransferase. Moreover, we confirmed that the bacterial polyynes disrupted cell membrane integrity and inhibited cell viability of Candida albicans by targeting ERG10, the homolog of MasL. Thus, this study demonstrated that acetyl-CoA acetyltransferase is a potential target for the development of antifungal agents.

2021 ◽  
Author(s):  
Ching-Chih Lin ◽  
Sin Yong Hoo ◽  
Chih Lin ◽  
Kai-Fa Huang ◽  
Ying-Ning Ho ◽  
...  

Bacterial polyynes are highly active natural products with a broad-spectrum of antimicrobial activities. However, their detailed mechanism of action remains unclear. Through integrating comparative genomics, transcriptomics, functional genetics, and metabolomics analysis, we identified a unique polyyne resistance gene, masL (encoding acetyl-CoA acetyltransferase), from the biosynthesis gene cluster (BGC) dominant for the production of antifungal polyynes (massilin A, massilin B, collimonin C, and collimonin D) in Massilia sp. YMA4. Phylogenic and chemotaxonomic analyses characterized the core architecture of bacterial polyyne BGC. The crystallographic analysis of the MasL-collimonin C complex indicated that bacterial polyynes serve as a covalent inhibitor of acetyl-CoA acetyltransferase. Moreover, we confirmed that the bacterial polyynes disrupted cell membrane integrity and inhibited cell viability of Candida albicans by targeting ERG10 (homolog of MasL). Overall, understanding the antifungal mechanism of bacterial polyynes presented herein will be useful for the development of polyynes for fungal infections.


2017 ◽  
Vol 4 (02) ◽  
pp. e59-e65 ◽  
Author(s):  
Sílvia Mendonça ◽  
Carla de Vasconcelos ◽  
Jader Cruz ◽  
Danilo Roman-Campos ◽  
José Menezes-Filho ◽  
...  

AbstractThe scientific interest in (+)-usnic acid has grown because of its antitumor, cytotoxic, and antimicrobial activities as well as weight loss. However, overuse of usnic acid has been related with severe hepatotoxicity, making its use questionable. In this study, we decided to expand the knowledge of usnic acid biological activities by characterizing its effects on the mammalian myocardium as a potential pharmacological target. Usnic acid was isolated from samples of Cladonia substellata and submitted to chemical characterization. Molecular inclusion complexes of usnic acid with hydroxypropyl β-cyclodextrin were prepared to improve its water solubility. The effects of usnic acid on the atrial contractility and Ca2+ influx were carried out in the left atrium of guinea pigs and the effect of usnic acid on the L-type Ca2+ current was performed in rat ventricular cardiomyocytes enzymatically isolated. To evaluate the membrane integrity of cells subjected to usnic acid, we used histological procedures. Usnic acid reduced atrial contraction with an EC50 of 43.0±1.0 μM. This effect was related to a reduction of Ca2+ entry in myocardial cells. In isolated cardiac myocytes, usnic acid at 100 μM inhibited the L-type Ca2+ current by 73.0%. In addition, usnic acid caused an irreversible myocardial contracture, reflecting a serious disturbance of the intracellular Ca2+ homeostasis. Such an effect could not be ascribed to tissue death because cell membrane integrity was confirmed by histological observation. Taken together, our results show that usnic acid impairs cardiac function. Clearly more studies will be necessary to allow further applications of this natural product.


2021 ◽  
Author(s):  
Ruifang Li ◽  
Mengke Tao ◽  
Shang Li ◽  
Xueqin Wang ◽  
Yanhui Yang ◽  
...  

Antimicrobial peptides (AMPs) are conventional antibiotic alternatives due to their broad-spectrum antimicrobial activities and special mechanisms of action against pathogens. The antifungal peptide CGA-N12 was originally derived from human chromogranin A (CGA) and consists of the 65th to 76th amino acids of the CGA N-terminal region. In the present study, we found that CGA-N12 had fungicidal activity and exhibited time-dependent inhibition activity against Candida tropicalis. CGA-N12 entered the cells to exert its antagonist activity. The internalization of CGA-N12 was energy-dependent and accompanied by actin cytoskeleton-, clathrin-, sulfate proteoglycan-, endosome-, and lipid-depleting agent-mediated endocytosis. Moreover, the CGA-N12 internalization pathway was related to the peptide concentration. The effects of CGA-N12 on the cell membrane were investigated. CGA-N12 at low concentration less than 4×MIC100 did not destroy the cell membrane. While with increasing concentration, the damage to the cell membrane caused by CGA-N12 became more serious. At concentrations greater than 4×MIC100, CGA-N12 destroyed the cell membrane integrity. Therefore, the membrane activity of CGA-N12 is concentration dependant.


2020 ◽  
Vol 13 ◽  
Author(s):  
Milad Ashrafizadeh ◽  
Saeed Samarghandian ◽  
Kiavash Hushmandi ◽  
Amirhossein Zabolian ◽  
Md Shahinozzaman ◽  
...  

Background: Ischemia/reperfusion (I/R) injury is a serious pathologic event that occurs due to restriction in blood supply to an organ, followed by hypoxia. This condition leads to enhanced levels of pro-inflammatory cytokines such as IL-6 and TNF-, and stimulation of oxidative stress via enhancing reactive oxygen species (ROS) levels. Upon reperfusion, blood supply increases, but it deteriorates condition, and leads to generation of ROS, cell membrane disruption and finally, cell death. Plant derived-natural compounds are well-known due to their excellent antioxidant and anti-inflammatory activities. Quercetin is a flavonoid exclusively found in different vegetables, herbs, and fruits. This naturally occurring compound possesses different pharmacological activities making it appropriate option in disease therapy. Quercetin can also demonstrate therapeutic effects via affecting molecular pathways such as NF-B, PI3K/Akt and so on. Methods: In the present review, we demonstrate that quercetin administration is beneficial in ameliorating I/R injury via reducing ROS levels, inhibition of inflammation, and affecting molecular pathways such as TLR4/NF-B, MAPK and so on. Results and conclusion: Quercetin can improve cell membrane integrity via decreasing lipid peroxidation. Apoptotic cell death is inhibited by quercetin via down-regulation of Bax, and caspases, and upregulation of Bcl-2. Quercetin is able to modulate autophagy (inhibition/induction) in decreasing I/R injury. Nanoparticles have been applied for delivery of quercetin, enhancing its bioavailability and efficacy in alleviation of I/R injury. Noteworthy, clinical trials have also confirmed the capability of quercetin in reducing I/R injury.


2021 ◽  
Vol 5 (1) ◽  
Author(s):  
Marie C. Lefevre ◽  
Gerwin Dijk ◽  
Attila Kaszas ◽  
Martin Baca ◽  
David Moreau ◽  
...  

AbstractGlioblastoma is a highly aggressive brain tumor, very invasive and thus difficult to eradicate with standard oncology therapies. Bioelectric treatments based on pulsed electric fields have proven to be a successful method to treat cancerous tissues. However, they rely on stiff electrodes, which cause acute and chronic injuries, especially in soft tissues like the brain. Here we demonstrate the feasibility of delivering pulsed electric fields with flexible electronics using an in ovo vascularized tumor model. We show with fluorescence widefield and multiphoton microscopy that pulsed electric fields induce vasoconstriction of blood vessels and evoke calcium signals in vascularized glioblastoma spheroids stably expressing a genetically encoded fluorescence reporter. Simulations of the electric field delivery are compared with the measured influence of electric field effects on cell membrane integrity in exposed tumor cells. Our results confirm the feasibility of flexible electronics as a means of delivering intense pulsed electric fields to tumors in an intravital 3D vascularized model of human glioblastoma.


Foods ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 1203
Author(s):  
Huan Zhang ◽  
Jianhang Xu ◽  
Qian Chen ◽  
Hui Wang ◽  
Baohua Kong

As functional starter cultures and potential probiotics, the ability of lactic acid bacteria to resist oxidative stress is essential to maintain viability and functional properties. This study investigates the effects of H2O2 at different concentrations (0, 1, 2, and 3 mM) on the physiological, morphological, and antioxidant properties of Pediococcus pentosaceus R1 and Lactobacillus fermentum R6 isolated from Harbin dry sausages. The increase in H2O2 concentration induced a significant increase in reactive oxygen species and a decrease in intracellular ATP levels (p < 0.05). Based on scanning electron microscopy, transmission electron microscopy, and electric conductivity analysis, H2O2 stress caused cell deformation, the destruction of cell membrane integrity, partial loss of the cytoplasm, and an increase in the cell conductivity of both strains. H2O2 stress with 1 mM or 2 mM concentrations could effectively improve the scavenging rates of free radicals, the activities of superoxide dismutase and glutathione peroxide, and the total antioxidant capacity of both strains (p < 0.05). In conclusion, an appropriate oxidative stress contributed to the activation of the antioxidant defense system of both strains, conferred strains a better effect in inhibiting the oxidation of fermented foods, and improved the health of the host.


2016 ◽  
Vol 141 ◽  
pp. 291-300 ◽  
Author(s):  
Jonas Hedberg ◽  
Hanna L. Karlsson ◽  
Yolanda Hedberg ◽  
Eva Blomberg ◽  
Inger Odnevall Wallinder

2007 ◽  
Vol 97 (2) ◽  
pp. 321-328 ◽  
Author(s):  
S. Aisling Aherne ◽  
Joseph P. Kerry ◽  
Nora M. O'Brien

Experimental evidence suggests that most herbs and spices possess a wide range of biological and pharmacological activities that may protect tissues against O2-induced damage. The objectives of the present study were: first, to determine the effects of plant extracts on the viability, membrane integrity, antioxidant status and DNA integrity of Caco-2 cells and second, to investigate the cytoprotective and genoprotective effects of these plant extracts against oxidative stress in Caco-2 cells. The plant extracts examined were rosemary (Rosmarinus officinalis L.), oregano (Origanum vulgare L.), sage (Salvia officinalis L.) and echinacea (Echinacea purpurea L.). Cell membrane integrity was assessed by the lactate dehydrogenase release assay. Viability was determined by the neutral red uptake assay (NRUA) and the concentration of compound that resulted in 50 % cell death (IC50) was calculated. Antioxidant status of the cells was assessed by measuring GSH content, catalase activity and superoxide dismutase activity. To examine their cytoprotective and genoprotective effects, Caco-2 cells were pre-treated with each plant extract for 24 h followed by exposure to H2O2. DNA damage was assessed by the comet assay and cell injury was determined by the NRUA. Rosemary was the most toxic (IC50 123 μg/ml) and echinacea the least toxic (IC50 1421 μg/ml). Sage was the only plant extract to affect the antioxidant status of the cells by increasing GSH content. Sage, oregano and rosemary protected against H2O2-induced DNA damage (olive tail moment and percentage tail DNA), whereas protection against H2O2-induced cytotoxicity was afforded by sage only.


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