Identification of Anti-Inflammatory and Anti-Hypertensive Drugs as Inhibitors of Bacterial Diguanylate Cyclases

Abstract

Biofilms are widely present in many human chronic infections, often more resistant to treatment with antibiotics. Bacterial diguanylate cyclases (DGCs) synthesize cyclic dimeric guanosine monophosphate (c-di-GMP) from two guanosine-5'-triphosphate (GTP) molecules. c-di-GMP is a central second messenger controlling biofilm formation, turning this class of enzymes an attractive target to prevent and disrupt biofilms of pathogenic bacteria. Here, we apply an in silico ligand-and target-based hybrid method to screen potential DGC inhibitors from an FDA-approved drug databank. Mass spectrometry assays confirmed that seven screened compounds selectively bound to the GTP active site of P. aeruginosa WspR GGDEF domain. Four out of those, including the anti-inflammatory sulfasalazine and the anti-hypertensive eprosartan, inhibited distinct DGCs (P. aeruginosa WspR and E. coli YdeH) in the micromolar range. Sulfasalazine and eprosartan reduced aggregation in solution of E. coli overexpressing WspR or YdeH. Similar anti-aggregation effects were also observed for sulfasalazine-related anti-inflammatory drugs sulfadiazine and sulfathiazole, the latter a previously described anti-biofilm agent. The optimized pharmacokinetic properties and toxicological profiles of the DGC inhibitors could be promising candidates for new anti-microbial agents based on the drug reposition strategy.Keywords: c-di-GMP, diguanylate cyclase enzymes, bacterial biofilm, virtual screening, drug repositioning IntroductionBacterial biofilms, a multicellular community encased in an extracellular matrix, are commonly related to persistent infections, usually less susceptible to antibiotic treatments when compared to planktonic cells. [1][2][3] According to the National Institute of Health, 4 up to 80% of human bacterial infections involve biofilm-associated microorganisms. For instance, biofilm formation plays a crucial role in microbe pathogenicity such as Legionnaire's disease, endocarditis, pneumonia accompanied by cystic fibrosis and infections of urogenital and gastrointestinal tracts. 5,6 Furthermore, biofilm infections promote devastating effects on medical device implanted and immunocompromised individuals, representing a major medical and economic predicament. 7 The burden on public health due to chronic biofilm contaminations urge for the development of new chemotherapeutic approaches. Cellular processes controlling biofilm formation and dispersion, such as quorum sensing systems and metabolic pathways, are important targets for the discovery of new bioactive compounds. 8-10The second messenger bis-(3'-5')-cyclic dimeric guanosine monophosphate (c-di-GMP) is a key regulator of bacterial behavior, especially controlling the switch between the motile planktonic and sedentary biofilm-associated lifestyles. Cyclic di-GMP stimulates the biosynthesis of adhesins and exopolysaccharide matrix substances in biofilms and inhibits various forms of motility. In general, low intracellular c-di-GMP levels are associated with freeswimming cells, whereas bacter...

Berberine and its structural analogs have differing effects on functional profiles of individual gut microbiomes

“…5 For example, Wiggers et al demonstrated that while sulfasalazine inhibited bacterial diguanylate cyclase inhibitor, its two structurally related molecules sulfadiazine and sulfathiazole did not. 6 Notably, current structure-activity studies are based on single strains of bacteria. The human gut microbiome is composed of different bacteria, and the composition of the gut microbiome is different between individuals.…”

Screening for Diguanylate Cyclase (DGC) Inhibitors Mitigating Bacterial Biofilm Formation

“…The big difference between the IC 50 values of eprosartan for the different DGCs indicates that not only the key conserved residues interacting with the substrate GTP in DGCs but also different A-site peripheral residues should be considered for designing a virtual inhibitor screening to discover inhibitors with a broad DGC spectrum. Both compounds reduce aggregation of E. coli in the culture broth, suggesting that these two chemicals have anti-biofilm property in vivo (Wiggers et al, 2018).…”

“…Recently, Wiggers et al screened 1500 FDA-approved drugs in the DrugBank database through a virtual screening method to find competitive inhibitors binding to the A-site of the DGC, C. crescentus PleD (Wiggers et al, 2018). The authors used the combination of the molecular docking strategy and ligandbased methods.…”