Small Molecule Restores Itaconate Sensitivity inSalmonella enterica: A Potential New Approach to Treating Bacterial Infections

ChemBioChem ◽  
2016 ◽  
Vol 17 (16) ◽  
pp. 1513-1517 ◽  
Author(s):  
Fabien Hammerer ◽  
Justin H. Chang ◽  
Dustin Duncan ◽  
Angel Castañeda Ruiz ◽  
Karine Auclair
2018 ◽  
Vol 243 (6) ◽  
pp. 538-553 ◽  
Author(s):  
Nathan P Coussens ◽  
Ashley L Molinaro ◽  
Kayla J Culbertson ◽  
Tyler Peryea ◽  
Gergely Zahoránszky-Köhalmi ◽  
...  

The increasing emergence of multidrug-resistant bacteria is recognized as a major threat to human health worldwide. While the use of small molecule antibiotics has enabled many modern medical advances, it has also facilitated the development of resistant organisms. This minireview provides an overview of current small molecule drugs approved by the US Food and Drug Administration (FDA) for use in humans, the unintended consequences of antibiotic use, and the mechanisms that underlie the development of drug resistance. Promising new approaches and strategies to counter antibiotic-resistant bacteria with small molecules are highlighted. However, continued public investment in this area is critical to maintain an edge in our evolutionary “arms race” against antibiotic-resistant microorganisms. Impact statement The alarming increase in antibiotic-resistant microorganisms is a rapidly emerging threat to human health throughout the world. Historically, small molecule drugs have played a major role in controlling bacterial infections and they continue to offer tremendous potential in countering resistant organisms. This minireview provides a broad overview of the relevant issues, including the diversity of FDA-approved small molecule drugs and mechanisms of drug resistance, unintended consequences of antibiotic use, the current state of development for small molecule antibacterials and financial challenges that impact progress towards novel therapies. The content will be informative to diverse stakeholders, including clinicians, basic scientists, translational scientists and policy makers, and may be used as a bridge between these key players to advance the development of much-needed therapeutics.


Blood ◽  
2019 ◽  
Vol 133 (1) ◽  
pp. 94-99 ◽  
Author(s):  
Katelyn Paz ◽  
Ryan Flynn ◽  
Jing Du ◽  
Jun Qi ◽  
Leo Luznik ◽  
...  

Abstract Patient outcomes for steroid-dependent or -refractory chronic graft-versus-host diesease (cGVHD) are poor, and only ibrutinib has been US Food and Drug Administration (FDA) approved for this indication. cGVHD is often driven by the germinal center (GC) reaction, in which T follicular helper cells interact with GC B cells to produce antibodies that are associated with disease pathogenesis. The transcriptional corepressor B-cell lymphoma 6 (BCL6) is a member of the Broad-complex, Tramtrack, and Bric-abrac/poxvirus and zinc finger (BTB/POZ) transcription factor family and master regulator of the immune cells in the GC reaction. We demonstrate that BCL6 expression in both donor T cells and B cells is necessary for cGVHD development, pointing to BCL6 as a therapeutic cGVHD target. A small-molecule BCL6 inhibitor reversed active cGVHD in a mouse model of multiorgan system injury with bronchiolitis obliterans associated with a robust GC reaction, but not in cGVHD mice with scleroderma as the prominent manifestation. For cGVHD patients with antibody-driven cGVHD, targeting of BCL6 represents a new approach with specificity for a master GC regulator that would extend the currently available second-line agents.


2019 ◽  
Author(s):  
Joseph Hardie ◽  
Javier A. Mas-Rosario ◽  
Siyoung Ha ◽  
Erik M. Rizzo ◽  
Michelle E. Farkas

ABSTRACTImmunotherapy has become a promising new approach for cancer treatment due to the immune system’s ability to remove tumors in a safe and specific manner. Many tumors express anti-inflammatory factors that deactivate the local immune response or recruit peripheral macrophages into pro-tumor roles. Because of this, effective and specific ways of activating macrophages into anti-tumor phenotypes is highly desirable for immunotherapy purposes. Here, the use of a small molecule TLR agonist as a macrophage activator for anti-cancer therapy is reported. This compound, referred to as PBI1, demonstrated unique activation characteristics and expression patterns compared to treatment with LPS, through activation of TLR4. Furthermore, PBI1 treatment resulted in anti-tumor immune behavior, enhancing macrophage phagocytic efficiency five-fold versus non-treated macrophages. Additive effects were observed via use of a complementary strategy (anti-CD47 antibody), resulting in ∼10-fold enhancement of phagocytosis, suggesting this small molecule approach could be used in conjunction with other therapeutics.


Author(s):  
Srushti Chavadapur ◽  
Shivaleela Biradar ◽  
Babu R. L.

Background:: Inflammatory diseases are one of the major concerns of today’s world, major disorders caused by inflammation includes, allergy, asthma, arthritis, hepatitis, autoimmune diseases, celiac disease etc. During most of these events, many protein and molecules expression were modulated and one such protein is AP-1 (c-Fos-c-Jun heterodimer complex). AP-1 is a dimeric protein activated by several physiological stimuli and environmental insults such as growth factors, polypeptide hormones, neurotransmitters, cytokines, cell-matrix interactions, UV irradiations, viral and bacterial infections. Objective:: Present study is mainly focus on designing of small molecule analogs to inhibit c-Fos-c-Jun complex, as the complex is involved in many inflammatory diseases and precisely involved in disease progression. Therefore, it had been considered as therapeutic target since more than a decade. Methods:: In the present study, an attempt was made to design the analogs of referral drug T-5224. 31 analogs of T-5224 were designed by chemoinformatics approach and subjected to ADMETox for screening. Results and Discussion:: Among the 16 compounds were found to pass the evaluation, all 16 compounds passed the toxicity evaluation except 7th molecule. The molecular docking study showed that the compounds 1, 2 and 16 were having high inhibition constant. Conclusion:: The preliminary results suggest the compounds 1, 2 and 16 are having the potential ligand binding capacity with cFos-cJun complex. Further analysis, with advanced tools, may results in potential small molecule to inhibit the c-Fosc- Jun complex.


Antibiotics ◽  
2019 ◽  
Vol 8 (4) ◽  
pp. 217 ◽  
Author(s):  
Laura Carro

Antibiotics are potent pharmacological weapons against bacterial pathogens, nevertheless their efficacy is becoming compromised due to the worldwide emergence and spread of multidrug-resistant bacteria or “superbugs”. Antibiotic resistance is rising to such dangerous levels that the treatment of bacterial infections is becoming a clinical challenge. Therefore, urgent action is needed to develop new generations of antibiotics that will help tackle this increasing and serious public health problem. Due to its essential role in bacterial cell division, the tubulin-like protein FtsZ has emerged as a promising target for the development of novel antibiotics with new mechanisms of action. This review highlights the medicinal chemistry efforts towards the identification of small-molecule FtsZ inhibitors with antibacterial activity in the last three years.


2020 ◽  
Vol 65 (1) ◽  
pp. e01247-20 ◽  
Author(s):  
Ville Y. P. Väre ◽  
Ryan F. Schneider ◽  
Haein Kim ◽  
Erica Lasek-Nesselquist ◽  
Kathleen A. McDonough ◽  
...  

ABSTRACTBacterial infections and the rise of antibiotic resistance, especially multidrug resistance, have generated a clear need for discovery of novel therapeutics. We demonstrated that a small-molecule drug, PKZ18, targets the T-box mechanism and inhibits bacterial growth. The T-box is a structurally conserved riboswitch-like gene regulator in the 5′ untranslated region (UTR) of numerous essential genes of Gram-positive bacteria. T-boxes are stabilized by cognate, unacylated tRNA ligands, allowing the formation of an antiterminator hairpin in the mRNA that enables transcription of the gene. In the absence of an unacylated cognate tRNA, transcription is halted due to the formation of a thermodynamically more stable terminator hairpin. PKZ18 targets the site of the codon-anticodon interaction of the conserved stem I and reduces T-box-controlled gene expression. Here, we show that novel analogs of PKZ18 have improved MICs, bactericidal effects against methicillin-resistant Staphylococcus aureus (MRSA), and increased efficacy in nutrient-limiting conditions. The analogs have reduced cytotoxicity against eukaryotic cells compared to PKZ18. The PKZ18 analogs acted synergistically with aminoglycosides to significantly enhance the efficacy of the analogs and aminoglycosides, further increasing their therapeutic windows. RNA sequencing showed that the analog PKZ18-22 affects expression of 8 of 12 T-box controlled genes in a statistically significant manner, but not other 5′-UTR regulated genes in MRSA. Very low levels of resistance further support the existence of multiple T-box targets for PKZ18 analogs in the cell. Together, the multiple targets, low resistance, and synergy make PKZ18 analogs promising drugs for development and future clinical applications.


2017 ◽  
Vol 23 (1) ◽  
pp. 94-101 ◽  
Author(s):  
Andrew F. Voter ◽  
Michael P. Killoran ◽  
Gene E. Ananiev ◽  
Scott A. Wildman ◽  
F. Michael Hoffmann ◽  
...  

Antibiotic-resistant bacterial infections are increasingly prevalent worldwide, and there is an urgent need for novel classes of antibiotics capable of overcoming existing resistance mechanisms. One potential antibiotic target is the bacterial single-stranded DNA binding protein (SSB), which serves as a hub for DNA repair, recombination, and replication. Eight highly conserved residues at the C-terminus of SSB use direct protein–protein interactions (PPIs) to recruit more than a dozen important genome maintenance proteins to single-stranded DNA. Mutations that disrupt PPIs with the C-terminal tail of SSB are lethal, suggesting that small-molecule inhibitors of these critical SSB PPIs could be effective antibacterial agents. As a first step toward implementing this strategy, we have developed orthogonal high-throughput screening assays to identify small-molecule inhibitors of the Klebsiella pneumonia SSB-PriA interaction. Hits were identified from an initial screen of 72,474 compounds using an AlphaScreen (AS) primary screen, and their activity was subsequently confirmed in an orthogonal fluorescence polarization (FP) assay. As an additional control, an FP assay targeted against an unrelated eukaryotic PPI was used to confirm specificity for the SSB-PriA interaction. Nine potent and selective inhibitors produced concentration–response curves with IC50 values of <40 μM, and two compounds were observed to directly bind to PriA, demonstrating the success of this screen strategy.


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