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
Project description:The physiological and transcriptional response of Nitrosomonas europaea biofilms to phenol and toluene was examined and compared to suspended cells. Biofilms were grown in Drip Flow Biofilm Reactors under continuous flow conditions of growth medium containing ammonia as growth substrate. The responses of N. europaea biofilms to the aromatic hydrocarbons phenol and toluene were determined during short-term (3 h) additions of each compound to the biofilms. Ammonia oxidation in the biofilms was inhibited 50% by 60 uM phenol and 100 uM toluene. These concentrations were chosen for microarray analysis of phenol- and toluene-exposed N. europaea biofilms. Liquid batch cultures of exponentially growing N. europaea cells were harvested alongside the biofilms to determine differential gene expression between attached and suspended growth of N. europaea. Four sample groups of N. europaea cells were used in this study, with biological triplicates of each group. Groups were: Control (untreated) biofilms, phenol-exposed biofilms, toluene-exposed biofilms, and exponentially growing suspended cells. Biofilms were grown in Drip Flow Biofilm Reactors containing 4 independent growth channels and subject to 2 hour inhibition tests. During each experiment, 2 biofilm channels served as control with no inhibitor present and the other 2 biofilm channels were exposed to either 60 uM phenol or 100 uM toluene. Nitrite production was monitored throughout the experiment, and the given concentrations of phenol and toluene resulted in 50% inhibition of ammonia oxidation by the biofilms. Suspended cells were grown in batch reactors. Three 4-plex NimbleGen microarray chips were used, and each chip contained one sample from each experimental group. QC of samples was determined by spectrophotometric methods and using Agilent bioanalyzer traces to determine purity and integrity of RNA and cDNA. A sample tracking report was used to verify the correct hybridization of each sample to the intended array.
Project description:The physiological and transcriptional response of Nitrosomonas europaea biofilms to phenol and toluene was examined and compared to suspended cells. Biofilms were grown in Drip Flow Biofilm Reactors under continuous flow conditions of growth medium containing ammonia as growth substrate. The responses of N. europaea biofilms to the aromatic hydrocarbons phenol and toluene were determined during short-term (3 h) additions of each compound to the biofilms. Ammonia oxidation in the biofilms was inhibited 50% by 60 uM phenol and 100 uM toluene. These concentrations were chosen for microarray analysis of phenol- and toluene-exposed N. europaea biofilms. Liquid batch cultures of exponentially growing N. europaea cells were harvested alongside the biofilms to determine differential gene expression between attached and suspended growth of N. europaea.
Project description:To investigate the etiology of the hyperandrogenic phenotype of polycystic ovary syndrome (PCOS), a prenatally androgenized (PNA) mouse model was validated and used for microarray analysis.
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: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:The objective was to identify the molecular mechanisms responsible for in vitro and in vivo efficacy of an anti-MYCN peptide nucleic acid on a preclinical model of alveolar rhabdomyosarcoma. Cells treated with a anti-MYCN PNA exhibit growth arrest and apoptosis, and in vivo tumor growth is blocked. Keywords: oncogene inhibition RH30 alveolar rhabdomyosarcoma cell line was treated with a 10uM concentration of anti-MYCN PNA or a mutated PNA devoid of any activity. After 12 hours RNA was extracted from untreated and treated cells and gene expression was analyzed by Affymetrix Gene Chips.
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.