Project description:Antisense peptide nucleic acids (PNAs) inhibiting mRNAs of essential genes provide a straight-forward way to repurpose our knowledge of bacterial regulatory RNAs for development of programmable species-specific antibiotics. While there is ample proof of PNA efficacy, their target selectivity and impact on bacterial physiology are poorly understood. Moreover, while antibacterial PNAs are typically designed to block mRNA translation, effects on target mRNA levels are not well-investigated. Here, we pioneer the use of global RNA-seq analysis to decipher PNA activity in a transcriptome-wide manner. We find that PNA-based antisense oligomer conjugates robustly decrease mRNA levels of the widely-used target gene, acpP, in Salmonella enterica, with limited off-target effects. Systematic analysis of several different PNA-carrier peptides attached not only shows different bactericidal efficiency, but also activation of stress pathways. In particular, KFF-, RXR- and Tat-PNA conjugates especially induce the PhoP/Q response, whereas the latter two additionally trigger several distinct pathways. We show that constitutive activation of the PhoP/Q response can lead to Tat-PNA resistance, illustrating the utility of RNA-seq for understanding PNA antibacterial activity. In sum, our study establishes an experimental framework for the design and assessment of PNA antimicrobials in the long-term quest to use these for precision editing of microbiota.
Project description:Here, we determined the ability of peptide nucleic acid (PNA) oligomers, coupled to different cell-penetrating peptides (CPPs), to interfere in regulatory RNA circuits of human blood-derived leukocytes. Using RNA-seq, FACS and confocal microscopy we identified octaarginin as a CPP enabling PNA delivery and sequence-dependent RNA inhibition in blood-derived myeloid cells at nanomolar concentration. At 200 nM, an R8-PNA targeting immune-regulatory microRNA-155 was delivered into nearly 100 % of human macrophages within 24 hours without apparent cytotoxicity, and globally de-repressed microRNA-155 target-mRNAs. This was not observed when coupling the PNA inhibitor to a K3 instead of the R8 peptide. We suggest that CPP choice is a fundamental success-determining factor for therapeutic RNA-inhibition in human myeloid leukocytes.
Project description:Antisense peptide nucleic acids (PNAs) that target mRNAs of essential bacterial genes exhibit specific bactericidal effects in several microbial species, but our mechanistic understanding of PNA activity and their target gene spectrum is limited. Here, we present a systematic analysis of PNAs targeting eleven essential genes with varying expression levels in uropathogenic Escherichia coli (UPEC). We demonstrate that UPEC is susceptible to killing by peptide-conjugated PNAs, especially when targeting the widely-used essential gene acpP. Our evaluation yields three additional promising target mRNAs for effective growth inhibition, i.e., dnaB, ftsZ, and rpsH. The analysis also shows that transcript abundance does not predict target vulnerability and that PNA-mediated growth inhibition is not universally associated with target mRNA depletion. Global transcriptomic analyses further reveal PNA sequence-dependent but also -independent responses, including the induction of envelope stress response pathways. Importantly, we show that the growth inhibitory capacity of 9mer PNAs is generally as effective as their 10mer counterparts. Overall, our systematic comparison of a range of PNAs targeting mRNAs of different essential genes in UPEC suggests important features for PNA design, reveals a general bacterial response to PNA conjugates and establishes the feasibility of using PNA antibacterials to combat UPEC.
Project description:To investigate the molecular mechanisms of miRNA-mRNA expression underlying this phenotype, ovarian samples from PNA and control mice were subjected to microRNA-seq and RNA-seq. Differential expression analyses were carried out to identify differentially expressed microRNAs (DEmiRs) and differentially expressed genes (DEGs). Target genes of DEmiRs were predicted by miRTarbase and visualization by Cytoscape. Functional annotation and pathway enrichment analyses for the DEGs and target genes were performed through the DAVID database. Then, to reveal the interactions involved in the pathogenesis of PCOS, the integrated analysis of miRNA-mRNA was performed in PNA mice vs. controls and granulosa cells (GCs) of PCOS women vs. health women. Protein–protein interaction (PPI) networks were established for these negatively regulated pairs via the STRING database. The expression and correlation of potential miRNAs and targets were further validated using RT-qPCR in more PNA mice and clinical human granulosa cells.
Project description:To investigate the molecular mechanism of PCOS underlying the hyperandrogenic phenotype, prenatally androgenized (PNA) mice were used to mimic this phenotype in women with PCOS. Methylated DNA binding domain sequencing (MBD-seq) and RNA-seq were performed on PNA mice (n=6) and control group (n=4) and validations were applied on ovarian samples from PNA mice (n=6) and control group (n=6) using MSP (methylation-specific PCR) and qPCR. The immunohistochemistry (IHC) and transmission electron microscope (TEM) profiling was separately conducted on tissue sections and granular cells of PNA mice (n=6) and control group (n=6). We identified 857 genes with differently methylated promoters and 3317 differently expressed genes in PNA mice and control group. We found that PCOS group had a down-regulation of Dnmt1 gene expression, accompanied by global hypomethylation compared with the control group. The promoter regions of Map3k1(mitogen-activated protein kinase kinase kinase 1) and Map1lc3ka (microtubule-associated protein1 light chain 3) were hypomethylated, accompanied by up-regulation of their mRNA expression, which may be involved in the regulation of PCOS through MAPK/p53 pathway activition and autophagy alteration.
Project description:To investigate the molecular mechanism of PCOS underlying the hyperandrogenic phenotype, prenatally androgenized (PNA) mice were used to mimic this phenotype in women with PCOS. Methylated DNA binding domain sequencing (MBD-seq) and RNA-seq were performed on PNA mice (n=6) and control group (n=4) and validations were applied on ovarian samples from PNA mice (n=6) and control group (n=6) using MSP (methylation-specific PCR) and qPCR. The immunohistochemistry (IHC) and transmission electron microscope (TEM) profiling was separately conducted on tissue sections and granular cells of PNA mice (n=6) and control group (n=6). We identified 857 genes with differently methylated promoters and 3317 differently expressed genes in PNA mice and control group. We found that PCOS group had a down-regulation of Dnmt1 gene expression, accompanied by global hypomethylation compared with the control group. The promoter regions of Map3k1(mitogen-activated protein kinase kinase kinase 1) and Map1lc3ka (microtubule-associated protein1 light chain 3) were hypomethylated, accompanied by up-regulation of their mRNA expression, which may be involved in the regulation of PCOS through MAPK/p53 pathway activition and autophagy alteration.
Project description:To test whether the addition of a peptide nucleic acid (PNA) clamp, which binds WT KRAS at codon 12, can increase the efficacy of mutation detection for KRASG12D within a targeted NGS setting. We tested the effect of clamping the wild-type KRAS sequence in a reference standard (Tru-Q 7, 1.3% Tier from Horizon Diagnostics, Cambridge, UK) with a KRAS c.35G>A mutation (KRASG12D) at an allelic frequency (AF) of 1.3% assessed by digital droplet PCR (ddPCR). We then re-tested the PNA on circulating-free DNA from a patient harbouring a KRASG12D mutation (at an AF of 3.2%, determined by ddPCR). Multiple runs were conducted using 10, 5, 2.5 and 1ng of DNA input.
Project description:Leishmania infantum is the causative agent of zoonotic visceral leishmaniasis in Mediterranean areas and also acts as an opportunistic parasite in HIV patients. Metacyclic promastigotes are transmitted during bloodmeals of the sand-fly host after development. Metacyclogenesis can be micmiked in axenic cultures and peanut lectin (PNA) agglutination followed by two-step centrifugation allows the separation of procyclic and metacyclic promastigotes in L. major. The purpose of this study is to isolate both fractions simultaneously from the same population of L. infantum in stationary phase of axenic culture and compare their expression profiles through DNA microarrays, specially focusing on metacyclic promastigotes. Whole-genome shotgun DNA microarrays were constructed and used to analyse the stationary-phase procyclic and metacyclic expression profiles. Four biological replicates of the experiment were performed and analysed, so that 322 clones with meaningful values of stage-specific regulation were selected. We found several genes dealing with primary metabolism, differentiation in procyclic promastigotes and with development of infectivity in metacyclic promastigotes. The differences we have found between the procyclic (PNA+) and metacyclic (PNA-) transcriptomes demonstrate that negative selection of metacyclic promastigotes through PNA agglutination is suitable in L. infantum and both fractions can be isolated. In addition, up-regulation of genes implied in lipophosphoglycan (LPG), proteophosphoglycan (PPG) and glycoprotein biosynthesis indicate that metacyclic promastigotes are related with infectivity. Keywords: comparative hybridization between cDNAs from procyclic PNA+ and metacyclic PNA- promastigotes of L.infantum