Here, we present a protocol for monitoring phagocytosis by M2-type macrophages using automated counting of phagocytic events with an imaging cytometer. We describe steps for isolating and differentiating peripheral blood mononuclear cell (PBMC)-derived monocytes into M2-like macrophages, preparing cancer cells expressing a green fluorescence marker, labeling with a pH-sensitive dye, and co-culturing with macrophages. We then outline procedures for enumerating phagocytic events using an imaging cytometer.
View Article and Find Full Text PDFGlioblastoma (GBM) is the most aggressive and frequently occurring type of malignant brain tumor in adults. The initiation, progression, and recurrence of malignant tumors are known to be driven by a small subpopulation of cells known as tumor-initiating cells or cancer stem cells (CSCs). GBM CSCs play a pivotal role in orchestrating drug resistance and tumor relapse.
View Article and Find Full Text PDFWe are very thankful to the commentator for pointing out the issues in the review article by Satam et al [...
View Article and Find Full Text PDFStudies on Hippo pathway regulation of tumorigenesis largely center on YAP and TAZ, the transcriptional co-regulators of TEAD. Here, we present an oncogenic mechanism involving VGLL and TEAD fusions that is Hippo pathway-related but YAP/TAZ-independent. We characterize two recurrent fusions, VGLL2-NCOA2 and TEAD1-NCOA2, recently identified in spindle cell rhabdomyosarcoma.
View Article and Find Full Text PDFCD24 is frequently overexpressed in ovarian cancer and promotes immune evasion by interacting with its receptor Siglec10, present on tumor-associated macrophages, providing a "don't eat me" signal that prevents targeting and phagocytosis by macrophages. Factors promoting CD24 expression could represent novel immunotherapeutic targets for ovarian cancer. Here, using a genome-wide CRISPR knockout screen, we identify GPAA1 (glycosylphosphatidylinositol anchor attachment 1), a factor that catalyzes the attachment of a glycosylphosphatidylinositol (GPI) lipid anchor to substrate proteins, as a positive regulator of CD24 cell surface expression.
View Article and Find Full Text PDFSolute carrier (SLC) transporters constitute a vast superfamily of transmembrane proteins tasked with regulating the transport of various substances such as metabolites, nutrients, ions, and drugs across cellular membranes. SLC transporters exhibit coordinated expression patterns across normal tissues, suggesting a tightly regulated regulatory network governing normal cellular functions. These transporters are crucial for the transport of various metabolites, including carbohydrates, proteins, lipids, and nucleic acids.
View Article and Find Full Text PDFIn the ongoing battle against antimicrobial resistance, phenotypic drug tolerance poses a formidable challenge. This adaptive ability of microorganisms to withstand drug pressure without genetic alterations further complicating global healthcare challenges. Microbial populations employ an array of persistence mechanisms, including dormancy, biofilm formation, adaptation to intracellular environments, and the adoption of L-forms, to develop drug tolerance.
View Article and Find Full Text PDFSulfur-containing classes of the scaffold "Arylthioindoles" have been evaluated for antibacterial activity; they demonstrated excellent potency against methicillin-resistant Staphylococcus aureus (MRSA) as well as against vancomycin-resistant strains and a panel of clinical isolates of resistant strains. In this study, we have elucidated the mechanism of action of lead compounds, wherein they target the cell wall of S. aureus.
View Article and Find Full Text PDFThe advent of next-generation sequencing (NGS) has brought about a paradigm shift in genomics research, offering unparalleled capabilities for analyzing DNA and RNA molecules in a high-throughput and cost-effective manner. This transformative technology has swiftly propelled genomics advancements across diverse domains. NGS allows for the rapid sequencing of millions of DNA fragments simultaneously, providing comprehensive insights into genome structure, genetic variations, gene expression profiles, and epigenetic modifications.
View Article and Find Full Text PDFThree platinum(II)-N-heterocyclic carbene (NHC) compounds [Pt(L)Cl](PF) (1), [Pt(L)(COD)](PF) (2) and [Pt(L)Cl] (3) were synthesized bearing pyridyl-functionalized butenyl-tethered (LH) and -butyl tethered (LH) NHC ligands, and their antibacterial activity against clinically relevant human pathogens was evaluated. Complex 1 was designed to have one of its metal coordination sites masked with a hemilabile butenyl group. The antibacterial activity spectrum against the ESKAPE panel of pathogens shows superior activity of 1 compared to 2 and 3 against the Gram-positive pathogen.
View Article and Find Full Text PDFTri and Tetra-substituted Methanes (TRSMs) are a significant structural motif in many approved drugs and prodrugs. There is increasing use of TRSM units in medicinal chemistry, and many derivatives are specifically designed to make drug-target interactions through new chemical space around TRSM moiety. In this perspective, we describe synthetic challenges for accessing a range of functionalized selective TRSMs and their molecular mechanism of action, especially as anti-infectives.
View Article and Find Full Text PDFMolnupiravir (MK-4482, EIDD-2801) is a promising broad-spectrum experimental antiviral developed by Merck & Co. It is a nucleoside analogue prodrug that undergoes rapid conversion into nucleoside triphosphate (NTP) by intracellular metabolic processes. NTP inhibits viral polymerase by acting as an alternative substrate.
View Article and Find Full Text PDFChagas disease is a vector-borne neglected tropical disease caused by Trypanosoma cruzi. It is a systemic and chronic parasitic infection which is endemic in 21 countries with 10 million cases worldwide and 12,000 annual deaths. Around 70 million people in the Americas are at risk of contracting this disease, and less than 1% of infected people are treated due to low disease awareness and limited access to treatment.
View Article and Find Full Text PDFMammalian cells do not produce chitin, an insoluble polymer of N-acetyl-D-glucosamine (GlcNAc), although chitin is a structural component of the cell wall of pathogenic microorganisms such as Candida albicans. Mammalian cells, including cells of the innate immune system elaborate chitinases, including chitotriosidase (Chit1), which may play a role in the anti-fungal immune response. In the current study, using knockout mice, we determined the role of Chit1 against systemic candidiasis.
View Article and Find Full Text PDFDiscovering novel drugs active against Mycobacterium tuberculosis (Mtb), the causative agent of tuberculosis (TB), is currently one of the most unmet medical needs. In this context, pretomanid (PA-824), a novel nitroimidazole prodrug that targets both replicating and nonreplicating cells, is being developed by TB Alliance under license from Novartis. In replicating Mtb, pretomanid inhibits mycolic acid biosynthesis, which is an important building block of Mtb cell wall.
View Article and Find Full Text PDFLascufloxacin hydrochloride (AM-1977) is a novel 8-methoxy fluoroquinolone antibacterial agent with a unique pharmacophore at the 1st and 7th positions of the quinoline nucleus developed by Kyorin Pharmaceutical Co., Ltd. (Tokyo, Japan).
View Article and Find Full Text PDFAntimicrobial resistance is a serious threat to human health worldwide, prompting research efforts on a massive scale in search of novel antibiotics to fill an urgent need for a remedy. Teixobactin, a macrocyclic depsipeptide natural product, isolated from uncultured bacteria (, displayed potent activity against several Gram-positive pathogenic bacteria. The distinct pharmacological profile and interesting structural features of teixobactin with nonstandard amino acid (three d-amino acids and l--enduracididine) residues attracted several research groups to work on this target molecule in search of novel antibiotics with new mechanism.
View Article and Find Full Text PDFImipenem/cilastatin sodium/relebactam is a combination of imipenem/cilastatin, a U.S. Food and Drug Administration (FDA)-approved antibiotic, and β-lactamase inhibitor relebactam which has been developed for the treatment of complicated urinary tract infection (cUTI) and complicated intra-abdominal infection (cIAI) due to drug-resistant bacterial pathogens.
View Article and Find Full Text PDFFascioliasis is a neglected tropical disease that is commonly caused by flatworms affecting both domestic ruminants and humans. Fascioliasis currently affects roughly 17 million people globally with additional 180 million people at risk of developing infection. Despite the gigantic patient pool, clinicians typically have very few treatment options available.
View Article and Find Full Text PDFInt J Antimicrob Agents
June 2019
Background: Antimicrobial resistance is an urgent threat affecting healthcare systems worldwide. Identification of novel molecules capable of escaping current resistance mechanisms and exhibiting potent activity against highly drug-resistant strains is the unmet need of the hour.
Methods: Whole cell growth inhibition assays were used to screen and identify novel inhibitors.
J Antimicrob Chemother
April 2019
Background: The emergence of drug-resistant bacteria is a major hurdle for effective treatment of infections caused by Mycobacterium tuberculosis and ESKAPE pathogens. In comparison with conventional drug discovery, drug repurposing offers an effective yet rapid approach to identifying novel antibiotics.
Methods: Ethyl bromopyruvate was evaluated for its ability to inhibit M.
Eravacycline is a novel, broad-spectrum, synthetic fluorocycline antibiotic for the treatment of complicated urinary tract infection (cUTI) and complicated intra-abdominal infection (cIAI) due to multidrug-resistant Gram-positive, Gram-negative and anaerobic bacteria that has demonstrated superior potency to that of currently marketed antibiotics. Tetraphase Pharmaceuticals has submitted a new drug application for eravacycline for the treatment of cIAI due to drug-resistant bacteria. In 2013, the U.
View Article and Find Full Text PDFOne of the mechanisms of drug-induced liver injury (DILI) involves alterations in bile acid (BA) homeostasis and elimination, which encompass several metabolic pathways including hydroxylation, amidation, sulfation, glucuronidation and glutathione conjugation. Species differences in BA metabolism may play a major role in the failure of currently used in vitro and in vivo models to predict reliably the DILI during the early stages of drug discovery and development. We developed an in vitro cofactor-fortified liver S9 fraction model to compare the metabolic profiles of the four major BAs (cholic acid, chenodeoxycholic acid, lithocholic acid and ursodeoxycholic acid) between humans and several animal species.
View Article and Find Full Text PDFMaintenance of bile acid (BA) homeostasis is essential to achieve their physiologic functions and avoid their toxic effects. The marked differences in BA composition between preclinical safety models and humans may play a major role in the poor prediction of drug-induced liver injury using preclinical models. We compared the composition of plasma and urinary BAs and their metabolites between humans and several animal species.
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