Hitting bacteria at the heart of the central dogma: sequence-specific inhibition

Abstract

An important objective in developing new drugs is the achievement of high specificity to maximize curing effect and minimize side-effects, and high specificity is an integral part of the antisense approach. The antisense techniques have been extensively developed from the application of simple long, regular antisense RNA (asRNA) molecules to highly modified versions conferring resistance to nucleases, stability of hybrid formation and other beneficial characteristics, though still preserving the specificity of the original nucleic acids. These new and improved second-and thirdgeneration antisense molecules have shown promising results. The first antisense drug has been approved and more are in clinical trials. However, these antisense drugs are mainly designed for the treatment of different human cancers and other human diseases. Applying antisense gene silencing and exploiting RNA interference (RNAi) are highly developed approaches in many eukaryotic systems. But in bacteria RNAi is absent, and gene silencing by antisense compounds is not nearly as well developed, despite its great potential and the intriguing possibility of applying antisense molecules in the fight against multiresistant bacteria. Recent breakthrough and current status on the development of antisense gene silencing in bacteria including especially phosphorothioate oligonucleotides (PS-ODNs), peptide nucleic acids (PNAs) and phosphorodiamidate morpholino oligomers (PMOs) will be presented in this review.

Putative Inv Is Essential for Basolateral Invasion of Caco-2 Cells and Acts Synergistically with OmpA To Affect In Vitro and In Vivo Virulence of Cronobacter sakazakii ATCC 29544

“…4). The expression of antisense mRNA from a multicopy plasmid has been successfully used in previous studies (40,41) that were based on the silencing of the gene expression by preventing the synthesis of the protein (42,43). We introduced here a reverse complement of the complete inv gene (r-inv) into the pBAD-TOPO vector, resulting in the production of a fused transcript that was flanked by thioredoxin-and His tag-coding sequences.…”

Antisense Antibacterials: From Proof-Of-Concept to Therapeutic Perspectives

“…Their growth inhibitory activity relies on sequence-specific inhibition of gene expression, which offers the potential for high specificity in immediate bacteriocidal or bacteriostatic therapeutic consequences (Rasmussen & et al, 2007). However, the fundamental requirements for potent antisense activity include sufficient concentration of antisense agent at the most sensitive targeting site, an ability to hybridize to the target mRNA sequence, the capacity of the ODN/mRNA duplex to interfere with gene expression, and sufficient biological stability of the antisense agent.…”

Bolaamphiphile-based nanocomplex delivery of phosphorothioate gapmer antisense oligonucleotides as a treatment for <em>Clostridium difficile</em>

“…One alternative treatment modality is the use of "antisense antibiotics," which can prevent the expression of bacterial genes essential for growth or virulence through posttranscriptional mechanisms. [8][9][10][11][12] This approach could potentially provide species-specific targeting of bacteria, while also providing multiple molecular targets beyond bacterial killing.…”

“…These alkyl modifications provide protection from nuclease attack, with an increased affinity to target mRNA and with an improved lipophilic character favorable for lipid bilayer diffusion. 36 Gapmer annealing to complementary mRNA can disrupt translation due to steric blocking of ribosome read-through and by recognition and degradation of the RNA-gapmer duplexes by cellular RNase H. 10,37 Materials and methods…”