thiourea and Cystic-Fibrosis

The aim of this study was to establish the antimicrobial activities of S-(3,4-dichlorobenzyl)isothiourea hydrochloride (A22) and a series of structurally related compounds against multidrug-resistant (MDR) bacteria. The minimum inhibitory concentrations (MICs) of 21 compounds were determined against 18 strains of pathogenic bacteria in addition to Pseudomonas aeruginosa (n=19) and Burkholderia cepacia complex (BCC) (n=20) isolated from the sputa of cystic fibrosis patients. Selected compounds were tested against further isolates, including P. aeruginosa (n=100), BCC (n=12) and Stenotrophomonas maltophilia (n=19). The interaction of S-(4-chlorobenzyl)isothiourea hydrochloride (C2) in combination with conventional antimicrobials was examined against 10 P. aeruginosa strains. Selected compounds were also tested against Enterobacteriaceae producing NDM-1 carbapenemase (n=64) and meticillin-resistant Staphylococcus aureus (MRSA) (n=37). Of the 21 compounds, 14 showed antimicrobial activity that was generally more pronounced against Gram-negative bacteria. Against P. aeruginosa, the most active compound was C2 [MIC for 50% of the organisms (MIC(50))=32μg/mL]. This compound was also the most active against BCC, with all isolates inhibited by 64μg/mL. For all ten strains of P. aeruginosa subjected to combination testing with C2 and conventional antimicrobials, a bactericidal effect was achieved with at least one combination. C2 and A22 both showed strong activity [MIC for 90% of the organisms (MIC(90))=4μg/mL] against Enterobacteriaceae that produced NDM-1 carbapenemase. Finally, S-(4-chlorobenzyl)-N-(2,4-dichlorophenyl)isothiourea hydrochloride showed good activity (MIC(90)=8μg/mL) against MRSA. This work establishes the activity of isothiourea derivatives against a broad range of clinically important MDR bacteria.

Topics: Anti-Bacterial Agents; Bacterial Infections; Burkholderia cepacia complex; Cystic Fibrosis; Drug Resistance, Multiple, Bacterial; Gram-Negative Bacteria; Gram-Positive Bacteria; Humans; Microbial Sensitivity Tests; Pseudomonas aeruginosa; Thiourea

Inflammatory lung disease is the major cause of morbidity and mortality in cystic fibrosis (CF); understanding what produces dysregulated innate immune responses in CF cells will be pivotal in guiding the development of novel anti-inflammatory therapies. To elucidate the molecular mechanisms that mediate exaggerated inflammation in CF following TLR signaling, we profiled global gene expression in immortalized human CF and non-CF airway cells at baseline and after microbial stimulation. Using complementary analysis methods, we observed a signature of increased stress levels in CF cells, specifically characterized by endoplasmic reticulum (ER) stress, the unfolded protein response (UPR), and MAPK signaling. Analysis of ER stress responses revealed an atypical induction of the UPR, characterized by the lack of induction of the PERK-eIF2α pathway in three complementary model systems: immortalized CF airway cells, fresh CF blood cells, and CF lung tissue. This atypical pattern of UPR activation was associated with the hyperinflammatory phenotype in CF cells, as deliberate induction of the PERK-eIF2α pathway with salubrinal attenuated the inflammatory response to both flagellin and Pseudomonas aeruginosa. IL-6 production triggered by ER stress and microbial stimulation were both dependent on p38 MAPK activity, suggesting a molecular link between both signaling events. These data indicate that atypical UPR activation fails to resolve the ER stress in CF and sensitizes the innate immune system to respond more vigorously to microbial challenge. Strategies to restore ER homeostasis and normalize the UPR activation profile may represent a novel therapeutic approach to minimize lung-damaging inflammation in CF.

Topics: Cells, Cultured; Cinnamates; Cystic Fibrosis; eIF-2 Kinase; Endoplasmic Reticulum; Endoplasmic Reticulum Stress; Epithelial Cells; Eukaryotic Initiation Factor-2; Flagellin; Gene Expression Profiling; Gene Expression Regulation; Humans; Immunity, Innate; Interleukin-6; Lung; p38 Mitogen-Activated Protein Kinases; Pneumonia; Pseudomonas aeruginosa; Signal Transduction; Thiourea; Unfolded Protein Response

Topics: Animals; Anura; Biological Transport, Active; Chlorides; Cystic Fibrosis; Gastric Mucosa; Histamine; Humans; Hydrogen-Ion Concentration; In Vitro Techniques; Membrane Potentials; Metiamide; Thiourea

Topics: Adolescent; Child; Cystic Fibrosis; Genetics, Medical; Geriatrics; Humans; Infant; Phenylthiourea; Sex; Taste; Thiourea