It has been demonstrated that impairing protein synthesis using drugs targeted against tRNA amino acid synthetases presents a promising strategy for the treatment of a wide variety of parasitic diseases, including malaria and toxoplasmosis. This is the first study evaluating tRNA synthetases as potential drug targets in ticks. RNAi knock-down of all tested tRNA synthetases had a strong deleterious phenotype on Ixodes ricinus feeding. Our data indicate that tRNA synthetases represent attractive, anti-tick targets warranting the design of selective inhibitors. Further, we tested whether these severely impaired ticks were capable of transmitting Borrelia afzelii spirochaetes. Interestingly, biologically handicapped I. ricinus nymphs transmitted B. afzelii in a manner quantitatively sufficient to develop a systemic infection in mice. These data suggest that initial blood-feeding, despite the incapability of ticks to fully feed and salivate, is sufficient for activating B. afzelii from a dormant to an infectious mode, enabling transmission and dissemination in host tissues.
- MeSH
- akaricidy farmakologie MeSH
- aminoacyl-tRNA-synthetasy antagonisté a inhibitory genetika MeSH
- Borrelia burgdorferi komplex MeSH
- klíšťata účinky léků mikrobiologie MeSH
- lidé MeSH
- lymeská nemoc farmakoterapie mikrobiologie přenos MeSH
- proteosyntéza účinky léků MeSH
- vyvíjení léků MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Human cytosolic prolyl-tRNA synthetase (HcProRS) catalyses the formation of the prolyl-tRNAPro, playing an important role in protein synthesis. Inhibition of HcProRS activity has been shown to have potential benefits in the treatment of fibrosis, autoimmune diseases and cancer. Recently, potent pyrazinamide-based inhibitors were identified by a high-throughput screening (HTS) method, but no further elaboration was reported. The pyrazinamide core is a bioactive fragment found in numerous clinically validated drugs and has been subjected to various modifications. Therefore, we applied a virtual screening protocol to our in-house library of pyrazinamide-containing small molecules, searching for potential novel HcProRS inhibitors. We identified a series of 3-benzylaminopyrazine-2-carboxamide derivatives as positive hits. Five of them were confirmed by a thermal shift assay (TSA) with the best compounds 3b and 3c showing EC50 values of 3.77 and 7.34 µM, respectively, in the presence of 1 mM of proline (Pro) and 3.45 µM enzyme concentration. Co-crystal structures of HcProRS in complex with these compounds and Pro confirmed the initial docking studies and show how the Pro facilitates binding of the ligands that compete with ATP substrate. Modelling 3b into other human class II aminoacyl-tRNA synthetases (aaRSs) indicated that the subtle differences in the ATP binding site of these enzymes likely contribute to its potential selective binding of HcProRS. Taken together, this study successfully identified novel HcProRS binders from our anti-tuberculosis in-house compound library, displaying opportunities for repurposing old drug candidates for new applications such as therapeutics in HcProRS-related diseases.
- MeSH
- adenosintrifosfát metabolismus MeSH
- aminoacyl-tRNA-synthetasy antagonisté a inhibitory MeSH
- biotest metody MeSH
- inhibitory enzymů chemie izolace a purifikace farmakologie MeSH
- konformace proteinů MeSH
- krystalografie rentgenová MeSH
- lidé MeSH
- ligandy MeSH
- molekulární modely MeSH
- počítačová simulace * MeSH
- pyrazinamid chemie MeSH
- vazebná místa MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
Chronic exposure to trichothecenes is known to disturb insulin-like growth factor 1 and signaling of insulin and leptin hormones and causes considerable growth retardation in animals. However, limited information was available on mechanisms underlying trichothecene-induced growth retardation. In this study, we employed an integrated transcriptomics, proteomics, and RNA interference (RNAi) approach to study the molecular mechanisms underlying trichothecene cytotoxicity in rat pituitary adenoma GH3 cells. Our results showed that trichothecenes suppressed the synthesis of growth hormone 1 (Gh1) and inhibited the eukaryotic transcription and translation initiation by suppressing aminoacyl-tRNA synthetases transcription, inducing eukaryotic translation initiation factor 2-alpha kinase 2 (EIF2AK2) and reducing eukaryotic translation initiation factor 5 a. The sulfhydryl oxidases , protein disulfide isomerase,and heat shock protein 90 (were greatly reduced, which resulted in adverse regulation of protein processing and folding. Differential genes and proteins associated with a decline in energy metabolism and cell cycle arrest were also found in our study. However, use of RNAi to interfere with hemopoietic cell kinase (Hck) and EIF2AK2 transcriptions or use of chemical inhibitors of MAPK, p38, Ras, and JNK partially reversed the reduction of Gh1 levels induced by trichothecenes. It indicated that the activation of MAPKs, Hck, and EIF2AK2 were important for trichothecene-induced growth hormone suppression. Considering the potential hazards of exposure to trichothecenes, our findings could help to improve our understanding regarding human and animal health implications.
- MeSH
- aminoacyl-tRNA-synthetasy antagonisté a inhibitory MeSH
- apoptóza účinky léků MeSH
- buněčné linie MeSH
- genetická transkripce účinky léků MeSH
- iniciační faktory antagonisté a inhibitory MeSH
- kinasa eIF-2 antagonisté a inhibitory MeSH
- krysa rodu rattus MeSH
- oxidoreduktasy antagonisté a inhibitory MeSH
- proteindisulfidisomerasy antagonisté a inhibitory MeSH
- proteiny tepelného šoku HSP90 antagonisté a inhibitory MeSH
- proteiny vázající RNA antagonisté a inhibitory MeSH
- proteomika * MeSH
- proteosyntéza účinky léků MeSH
- RNA interference účinky léků MeSH
- růstový hormon antagonisté a inhibitory MeSH
- stanovení celkové genové exprese * MeSH
- T-2 toxin analogy a deriváty farmakologie MeSH
- viabilita buněk účinky léků MeSH
- zvířata MeSH
- Check Tag
- krysa rodu rattus MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
