scholarly journals Structure-Guided Optimization of Small-Molecule Folate Uptake Inhibitors Targeting the Energy-Coupling Factor Transporters

2021 ◽  
Author(s):  
Alexander F. Kiefer ◽  
Spyridon Bousis ◽  
Mostafa M. Hamed ◽  
Eleonora Diamanti ◽  
Jörg Haupenthal ◽  
...  
Keyword(s):  
Cell Death ◽  
Small Molecule ◽  
Transport Mechanism ◽  
Energy Coupling ◽  
Antimicrobial Activities ◽  
Coupling Factor ◽  
Substrate Uptake ◽  
Cytotoxic Effects ◽  
Whole Cell ◽  
Membrane Bound

Here, we report on a potent class of substituted ureidothiophenes targeting energy-coupling factor (ECF) transporters, an unexplored target, which is not addressed by any antibiotic on the market. Since the ECF module is crucial for the vitamin transport mechanism, prevention of substrate uptake should ultimately lead to cell death. By utilizing a combination of virtual and functional whole-cell screening of our in-house library, the membrane-bound protein mediated uptake of folate could be effectively inhibited. Structure-based optimization of our hit compound yielded low-micromolar inhibitors, whereby the most active compounds showed in addition potent antimicrobial activities against a panel of clinically relevant Gram-positive pathogens without significant cytotoxic effects.

scholarly journals An efficient way to screen inhibitors of energy-coupling factor (ECF) transporters in bacteria uptake assay

2021 ◽  
Author(s):  
Spyridon Bousis ◽  
Steffen Winkler ◽  
Jörg Haupenthal ◽  
Francesco Fulco ◽  
Eleonora Diamanti ◽  
...  
Keyword(s):  
Cost Effective ◽  
Energy Coupling ◽  
Coupling Factor ◽  
Screening Assay ◽  
Vitro Assay ◽  
Whole Cell ◽  
Fast Solution ◽  
Uptake Assay ◽  
Biological Environment

Herein, we report a novel whole-cell screening assay using Lactobacillus casei as model microorganism to identify inhibitors of energy-coupling factor (ECF) transporters. This promising and underexplored target may have important pharmacological potential through modulation of vitamin homeostasis in bacteria and, importantly, it is absent in humans. The assay represents an alternative, cost-effective and fast solution to demonstrate the direct involvement of these membrane transporters in a native biological environment rather than using a low-throughput in vitro assay employing reconstituted proteins in a membrane bilayer system. Based on this new whole-cell screening approach, we demonstrated the optimization of a weak hit compound (2) into a small molecule (3) with improved in vitro and whole-cell activities. This study opens the possibility to quickly identify novel inhibitors of ECF transporters and optimize them based on structure–activity relationships.

Discovery of Antibacterial Agents Inhibiting the Energy-Coupling Factor (ECF) Transporters by Structure-Based Virtual Screening

2020 ◽  
Author(s):  
Eleonora Diamanti ◽  
Inda Setyawati ◽  
Spyridon Bousis ◽  
leticia mojas ◽  
lotteke Swier ◽  
...  
Keyword(s):  
Virtual Screening ◽  
Antibacterial Agents ◽  
Antimicrobial Agents ◽  
Energy Coupling ◽  
Coupling Factor ◽  
Design Synthesis ◽  
Screening Design ◽  
Starting Point ◽  
Wide Range ◽  
Vitamin Uptake

Here, we report on the virtual screening, design, synthesis and structure–activity relationships (SARs) of the first class of selective, antibacterial agents against the energy-coupling factor (ECF) transporters. The ECF transporters are a family of transmembrane proteins involved in the uptake of vitamins in a wide range of bacteria. Inhibition of the activity of these proteins could reduce the viability of pathogens that depend on vitamin uptake. Because of their central role in the metabolism of bacteria and their absence in humans, ECF transporters are novel potential antimicrobial targets to tackle infection. The hit compound’s metabolic and plasma stability, the potency (20, MIC Streptococcus pneumoniae = 2 µg/mL), the absence of cytotoxicity and a lack of resistance development under the conditions tested here suggest that this scaffold may represent a promising starting point for the development of novel antimicrobial agents with an unprecedented mechanism of action.<br>

scholarly journals Exposure of the cytoplasm to low-dose X-rays modifies ataxia telangiectasia mutated-mediated DNA damage responses

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Munetoshi Maeda ◽  
Masanori Tomita ◽  
Mika Maeda ◽  
Hideki Matsumoto ◽  
Noriko Usami ◽  
...  
Keyword(s):  
Dna Damage ◽  
Cell Death ◽  
Ataxia Telangiectasia ◽  
Kinase Inhibitor ◽  
Surrogate Marker ◽  
X Rays ◽  
Ataxia Telangiectasia Mutated ◽  
Whole Cell ◽  
X Ray ◽  
Dna Damage Responses

AbstractWe recently showed that when a low X-ray dose is used, cell death is enhanced in nucleus-irradiated compared with whole-cell-irradiated cells; however, the role of the cytoplasm remains unclear. Here, we show changes in the DNA damage responses with or without X-ray microbeam irradiation of the cytoplasm. Phosphorylated histone H2AX foci, a surrogate marker for DNA double-strand breaks, in V79 and WI-38 cells are not observed in nucleus irradiations at ≤ 2 Gy, whereas they are observed in whole-cell irradiations. Addition of an ataxia telangiectasia mutated (ATM) kinase inhibitor to whole-cell irradiations suppresses foci formation at ≤ 2 Gy. ABL1 and p73 expression is upregulated following nucleus irradiation, suggesting the induction of p73-dependent cell death. Furthermore, CDKN1A (p21) is upregulated following whole-cell irradiation, indicating the induction of cell cycle arrest. These data reveal that cytoplasmic radioresponses modify ATM-mediated DNA damage responses and determine the fate of cells irradiated at low doses.

scholarly journals Peppers: A “Hot” Natural Source for Antitumor Compounds

Molecules ◽  
2021 ◽  
Vol 26 (6) ◽  
pp. 1521
Author(s):  
Micael Rodrigues Cunha ◽  
Maurício Temotheo Tavares ◽  
Thais Batista Fernandes ◽  
Roberto Parise-Filho
Keyword(s):  
Cell Death ◽  
Cellular Responses ◽  
Biological Applications ◽  
Traditional Use ◽  
Cytotoxic Effects ◽  
Antiproliferative Effects ◽  
Naturally Occurring ◽  
Antitumor Compounds ◽  
Tumorigenic Cells ◽  
Ancient Civilizations

Piper, Capsicum, and Pimenta are the main genera of peppers consumed worldwide. The traditional use of peppers by either ancient civilizations or modern societies has raised interest in their biological applications, including cytotoxic and antiproliferative effects. Cellular responses upon treatment with isolated pepper-derived compounds involve mechanisms of cell death, especially through proapoptotic stimuli in tumorigenic cells. In this review, we highlight naturally occurring secondary metabolites of peppers with cytotoxic effects on cancer cell lines. Available mechanisms of cell death, as well as the development of analogues, are also discussed.

scholarly journals Identification of a small molecule as inducer of ferroptosis and apoptosis through ubiquitination of GPX4 in triple negative breast cancer cells

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Yahui Ding ◽  
Xiaoping Chen ◽  
Can Liu ◽  
Weizhi Ge ◽  
Qin Wang ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Cell Death ◽  
Small Molecule ◽  
Mode Of Action ◽  
Rna Silencing ◽  
Breast Cancer Cells ◽  
Triple Negative ◽  
Parent Compound ◽  
Aggressive Breast Cancer

Abstract Background TNBC is the most aggressive breast cancer with higher recurrence and mortality rate than other types of breast cancer. There is an urgent need for identification of therapeutic agents with unique mode of action for overcoming current challenges in TNBC treatment. Methods Different inhibitors were used to study the cell death manner of DMOCPTL. RNA silencing was used to evaluate the functions of GPX4 in ferroptosis and apoptosis of TNBC cells and functions of EGR1 in apoptosis. Immunohistochemical assay of tissue microarray were used for investigating correlation of GPX4 and EGR1 with TNBC. Computer-aided docking and small molecule probe were used for study the binding of DMOCPTL with GPX4. Results DMOCPTL, a derivative of natural product parthenolide, exhibited about 15-fold improvement comparing to that of the parent compound PTL for TNBC cells. The cell death manner assay showed that the anti-TNBC effect of DMOCPTL mainly by inducing ferroptosis and apoptosis through ubiquitination of GPX4. The probe of DMOCPTL assay indicated that DMOCPTL induced GPX4 ubiquitination by directly binding to GPX4 protein. To the best of our knowledge, this is the first report of inducing ferroptosis through ubiquitination of GPX4. Moreover, the mechanism of GPX4 regulation of apoptosis is still obscure. Here, we firstly reveal that GPX4 regulated mitochondria-mediated apoptosis through regulation of EGR1 in TNBC cells. Compound 13, the prodrug of DMOCPTL, effectively inhibited the growth of breast tumor and prolonged the lifespan of mice in vivo, and no obvious toxicity was observed. Conclusions These findings firstly revealed novel manner to induce ferroptosis through ubiquitination of GPX4 and provided mechanism for GPX4 inducing mitochondria-mediated apoptosis through up-regulation of EGR1 in TNBC cells. Moreover, compound 13 deserves further studies as a lead compound with novel mode of action for ultimate discovery of effective anti-TNBC drug.

Recent progress in small-molecule inhibitors for critical therapeutic targets of necroptosis

2021 ◽  
Author(s):  
Zhennan Fang ◽  
Huiqiang Wei ◽  
Wenfeng Gou ◽  
Leyuan Chen ◽  
Changfen Bi ◽  
...  
Keyword(s):  
Cell Death ◽  
Small Molecule ◽  
Future Development ◽  
Recent Progress ◽  
Small Molecule Inhibitors ◽  
Cell Necrosis ◽  
Significant Progress ◽  
Regulated Cell Death ◽  
Associated Proteins ◽  
Widespread Interest

Nonapoptotic types of regulated cell death have attracted widespread interest since the discovery that certain forms of cell necrosis can be regulated. In particular, research into cell necroptosis has made significant progress in connection with kidney, inflammatory, degenerative and neoplastic diseases. Inhibitors targeting the critical necroptosis-associated proteins RIPK1/3 and MLKL have been in development for more than a decade. Herein the authors compile a list of the known small-molecule inhibitors of these enzymes and representative structures of compounds co-crystallized with these proteins and put forward some thoughts regarding their future development.

scholarly journals Cytotoxicity of Environmentally Relevant Concentrations of Aluminum in Murine Thymocytes and Lymphocytes

2011 ◽  
Vol 2011 ◽  
pp. 1-7 ◽  
Author(s):  
Jamal Kamalov ◽  
David O. Carpenter ◽  
Irina Birman
Keyword(s):  
Flow Cytometry ◽  
Cell Death ◽  
Immune System ◽  
Dna Binding ◽  
Aluminum Chloride ◽  
Cell Swelling ◽  
Cytotoxic Effects ◽  
Minute Exposure ◽  
Low Concentrations ◽  
Dose Dependent

The effects of low concentrations of aluminum chloride on thymocytes and lymphocytes acutely dissociated from young mice were studied using flow cytometry with a DNA-binding dye. We demonstrate a rapid and dose-dependent injury in murine thymocytes and lymphocytes resulting from exposure to aluminum, as indicated by an increase in the entry into the cell of the DNA-binding dye, propidium iodine. A 60-minute exposure to 10 μM AlCl3caused damage of about 5% of thymocytes, while 50% were injured after 10 minutes at 20 μM. Nearly all thymocytes showed evidence of damage at 30 μM AlCl3after only 5 minutes of incubation. In lymphocytes, injury was observed at 15 μM AlCl3and less than 50% of cells were injured after a 60-minute exposure to 20 μM. Injury only rarely proceeded to rapid cell death and was associated with cell swelling. These results suggest that aluminum has cytotoxic effects on cells of the immune system.

Identification of types of membrane injuries and cell death using whole cell-based proton-sensitive field-effect transistor systems

The Analyst ◽  
2017 ◽  
Vol 142 (18) ◽  
pp. 3451-3458 ◽  
Author(s):  
Yuki Imaizumi ◽  
Tatsuro Goda ◽  
Akira Matsumoto ◽  
Yuji Miyahara
Keyword(s):  
Cell Death ◽  
Mammalian Cells ◽  
Field Effect ◽  
Field Effect Transistor ◽  
Ph Sensing ◽  
Membrane Injury ◽  
Whole Cell ◽  
Sensing Systems ◽  
Effect Transistor ◽  
Chemical Stimuli

Membrane injury and apoptosis of mammalian cells by chemical stimuli were distinguished using ammonia-perfused continuous pH-sensing systems.

In Vivo Interactions with (Tissue Culture Pretreated) Dermal Sheep Collagen

1991 ◽  
Vol 252 ◽  
Author(s):  
P. B. van Wachem ◽  
P. B. van Wachem ◽  
L. H. H. Olde Damink ◽  
P. J. Dijkstra ◽  
J. Feijen ◽  
...  
Keyword(s):  
Tissue Culture ◽  
Cell Death ◽  
Marked Reduction ◽  
Giant Cells ◽  
In Vitro Cytotoxicity ◽  
Cell Infiltration ◽  
Cytotoxic Effects ◽  
Lipid Formation

ABSTRACTPretreatment in tissue culture (TC) was previously found to markedly reduce the in vitro cytotoxicity of two types of crosslinked dermal sheep collagens (DSC's). This in vivo study confirms our in vitro results, in that TC-pretreatment of crosslinked DSC's resulted in the marked reduction or elimination of cytotoxic effects, such as increased cell infiltration, a deviant neutrophil-morphology, lipid formation and cell death. TC-pretreatment affected the crosslinked state of both DSC's in a different way, which could be deduced from the differences in gelatin-formation and presence of giant cells from macrophage- or fibroblast-origin. The results are explained in view of the differences in crosslinking.

Sign in / Sign up

Export Citation Format

Share Document