ABSTRACT: Tracing back the evolutionary route of the Enteroinvasive Escherichia coli (EIEC) and Shigella through the example of the highly pathogenic O96:H19 EIEC clone
Project description:The invasive bacteria recognition by host cells through autophagy is a key factor for determining bacterial infection. Enteroinvasive Escherichia coli (EIEC) express a protein IcsB, which in Shigella, is known for inactivating the bacterial degradation process. Once EIEC showed less expression of icsB when compared to S. flexneri, we proposed to investigate the autophagy caused by EIEC infection. Our results showed that IcsB protein is an important virulence factor in EIEC because it causes a camouflage of the bacteria in the eukaryotic cell. When there is low or none expression of the protein, the cell recognition of the invasive bacteria is high, decreasing the bacteria dissemination. This found confirms the importance of the gene transcription and the sequence, since the strain E. coli SM124/13, complemented with icsB from Shigella, showed higher dissemination efficiency inside of the host cell. Additionally, our results revealed that eukaryotic cell infected by EIEC or Shigella flexneri showed distinguish responses. In EIEC infection, the autophagy was activated in human cells, but not in a conventional mode. Our hypothesis is that EIEC is recognized by autophagy, being an important cell process for bacterial recognition.
Project description:The invasive bacteria recognition by host cells through autophagy is a key factor for determining bacterial infection. Enteroinvasive Escherichia coli (EIEC) express a protein IcsB, which in Shigella, is known for inactivating the bacterial degradation process. Once EIEC showed less expression of icsB when compared to S. flexneri, we proposed to investigate the autophagy caused by EIEC infection. Our results showed that IcsB protein is an important virulence factor in EIEC because it causes a camouflage of the bacteria in the eukaryotic cell. When there is low or none expression of the protein, the cell recognition of the invasive bacteria is high, decreasing the bacteria dissemination. This found confirms the importance of the gene transcription and the sequence, since the strain E. coli SM124/13, complemented with icsB from Shigella, showed higher dissemination efficiency inside of the host cell. Additionally, our results revealed that eukaryotic cell infected by EIEC or Shigella flexneri showed distinguish responses. In EIEC infection, the autophagy was activated in human cells, but not in a conventional mode. Our hypothesis is that EIEC is recognized by autophagy, being an important cell process for bacterial recognition.
Project description:The invasive bacteria recognition by host cells through autophagy is a key factor for determining bacterial infection. Enteroinvasive Escherichia coli (EIEC) express a protein IcsB, which in Shigella, is known for inactivating the bacterial degradation process. Once EIEC showed less expression of icsB when compared to S. flexneri, we proposed to investigate the autophagy caused by EIEC infection. Our results showed that IcsB protein is an important virulence factor in EIEC because it causes a camouflage of the bacteria in the eukaryotic cell. When there is low or none expression of the protein, the cell recognition of the invasive bacteria is high, decreasing the bacteria dissemination. This found confirms the importance of the gene transcription and the sequence, since the strain E. coli SM124/13, complemented with icsB from Shigella, showed higher dissemination efficiency inside of the host cell. Additionally, our results revealed that eukaryotic cell infected by EIEC or Shigella flexneri showed distinguish responses. In EIEC infection, the autophagy was activated in human cells, but not in a conventional mode. Our hypothesis is that EIEC is recognized by autophagy, being an important cell process for bacterial recognition.
Project description:Enteroinvasive Escherichia coli (EIEC) cause intestinal illness through the same pathogenic mechanism used by Shigella spp. The latter species can be typed through genomic and phenotypic methods used for E. coli and have been proposed for reclassification within E. coli species. Recently the first appearance of a highly pathogenic EIEC O96:H19 was described in Europe as the causative agent of two large outbreaks that occurred in Italy and in the United Kingdom. In contrast to Shigella spp and to the majority of EIEC strains, EIEC O96:H19 fermented lactose, lacked pathoadaptive mutations, and showed good fitness in extracellular environment, similarly to non-pathogenic E. coli, suggesting they have emerged following acquisition of the invasion plasmid by a non-pathogenic E. coli. Here we describe the whole genome comparison of two EIEC O96:H19 strains isolated from severe cases of diarrhea in Uruguay in 2014 with the sequences of EIEC O96:H19 available in the public domain. The phylogenetic comparison grouped all the O96:H19 strains in a single cluster, while reference EIEC strains branched into different clades with Shigella strains occupying apical positions. The comparison of the virulence plasmids showed the presence of a complete conjugation region in at least one O96:H19 EIEC. Reverse Transcriptase Real Time PCR experiments confirmed in this strain the expression of the pilin-encoding gene and conjugation experiments suggested its ability to mobilize an accessory plasmid in a recipient strain. Noteworthy, the tra region was comprised between two reversely oriented IS600 elements, which were also found as remnants in another EIEC O96:H19 plasmid lacking the tra locus. We hypothesize that an IS-mediated recombination mechanism may have caused the loss of the conjugation region commonly observed in EIEC and Shigella virulence plasmids. The results of this study support the hypothesis of EIEC originating from non-pathogenic E. coli through the acquisition of the virulence plasmid via conjugation. Remarkably, this study showed the ability of a circulating EIEC strain to mobilize plasmids through conjugation, suggesting a mechanism for the emergence of novel EIEC clones.
Project description:Dystrophin proteomic regulation in Muscular Dystrophies (MD) remains unclear. We report that a long noncoding RNA (lncRNA) H19 associates with dystrophin. To investigate the biological roles of this interaction in vivo, we performed mass spectrometry analysis of dystrophin and its associated proteins in H19-proficient and -deficient C2C12 myotubes. Mass spectrometry data indicated that in H19-proficient myotubes, dystrophin associates with components of dystrophin-associated protein complex (DPC); however, in H19-deficient myotubes, dystrophin associated with UBA1, UB2G1, TRIM63 ubiquitin E3 ligase and ubiquitin. In H19-deficient myotubes, dystrophin was post-translationally modified with K48-linked poly-ubiquitination at Lys3577 (referred to as Ub-DMD). This mass spectrometry study demonstrated that lncRNA H19, associates with dystrophin and inhibits E3 ligase-dependent Ub-DMD formation and its subsequent proteasomal degradation. Based on this study, H19 RNA oligonucleotides conjugated with a muscle homing ligand Agrin (referred to as AGR-H19) and Nifenazone, a TRIM63-specific small molecule inhibitor, reverses the dystrophin degradation in iPSC-derived skeletal muscle cells from Becker Muscular Dystrophy patients. Furthermore,treatment of mdx mice with exon-skipping reagent, in combination with either AGR-H19 or Nifenazone, dramatically stablized dystrophin, preserved skeletal/cardiac muscle histology, and improved strength/heart function. In summary, this mass spectrometry study paves the way to meaningful targeted therapeutics for BMD and certain DMD patients.
Project description:Galangin, a natural flavonoid, derived from honey and Alpinia officinarum Hance (Zingiberaceae) has excellent was anti-tumor and anti-inflammatory properties. w It has been extensively studied as a novel therapeutic agent forhich was widely used in the treatment of various cancers. However, the effect of galangin in HCC remains elusive. Using RNA sequencing, the differential expression of LncRNA in MHCC97H cells treated with galangin was investigated in the present study. Furthermore, the expression of H19 was also determined in MHCC97H cells following treatment with galangin. And the effect of knockdown and overexpression of H19 on cell apoptosis, cell cycle, migration and invasion of HCC cells was also evaluated. Moreover, the in vivo effect of galangin on tumor development was also determined in nude mice. This study identified aT total of 50 LncRNAs were to be significantly differentially expressed by RNA-seq analysis in MHCC97H cells treated with galangin. It has been demostreated that noncoding RNA H19 are abnormally expressed in different cancers. Our results showed that Besides, the expression of H19 was markedly reduced after following treatment with galangin treatment in MHCC97H cells. In addition, galangin could increase the occurrence of cell apoptosis. Moreover, compared to the Control group, the galangin-treated group inhibited cell migration and invasion in MHCC97H cells.To further investigated if H19 expression pattern affect cell apoptosis, migration and invasion, knock down and overexpression of H19 vector were constructed. The results of the knockdown of H19 expression showed knock down of H19 expression increased cell apoptosis and decreasedinhibited invasion. In addition, RNA-seq data showed also identified 161 mRNA which were was significantly differentially expressed after following treatment withof galangin. To further determine the underlying mechanism,confirmed cell apoptosis, p53 protein and its related proteins were was analyzed through micor RNA 675-3p (miR675-3p) which was in the H19 locus. Notably, Tthe results indicatedshowed that reduced knockdown of H19 and miR675 induced the protein expression of p53, eventually promoting cell apoptosis expression of H19 and miR675-3p increased p53 expression in MHCC97H cells. These results indicated that galangin promoted cell apoptosis through the regulation of H19 and miR675 expression in MHCC97H cells. Furthermorely, galangin was used to treated in nude mice. Tthe in vivo result showed that compared to the Control group, inhibited tumor growth was remarkably suppressed and reduced expression of H19 in galangin-treated group. Taken together, these results indicated that galangin regulated cell apoptosis which associate with p53 protein through H19 and miR675 expression in MHCC97H cells.Collectively, our data suggested that galangin plays a role in hepatocarcinogenesis through regulation of H19 expression pattern.
Project description:Treatment of pathological cardiac remodeling and subsequent heart failure represents an unmet clinical need. The well conserved lncRNA H19 shows as powerful therapeutic potential in the treatment of pathological cardiac hypertrophy. H19 is strongly repressed in failing hearts from mice, pigs and humans. Gene therapy using murine but also human H19 strongly attenuated heart failure even when cardiac hypertrophy was already established. Using microarray , GSEA and ChIP-Seq we identified a link between H19 and NFAT signalling. H19 physically interacts with PRC2 to epigenetically induced Tescalcin repression which in turn leads to reduced NFAT expression and activity.
Project description:Long non-coding RNAs (lncRNAs) regulate diverse cellular processes and are associated with many age-associated diseases. However, the function of lncRNAs in cellular senescence remains largely unknown. Here we characterize the role of lncRNA H19 in senescence. We show that H19 levels decline as cells undergo senescence, and depletion of H19 results in premature senescence. We find that repression of H19 is triggered by the loss of CTCF and prolonged activation of p53 as part of the senescence pathway. Mechanistically, the loss of H19 drives senescence via increased let7b mediated targeting of EZH2. We further demonstrate that H19 is required for senescence inhibition by the mTOR inhibitor rapamycin, where it maintains lncRNA H19 levels throughout the cellular lifespan and thus prevents the reduction of EZH2 that would otherwise lead to cellular senescence. Therefore, lncRNA H19 is crucial in maintaining the balance between sustained cell growth and the onset of senescence.
Project description:Treatment of pathological cardiac remodeling and subsequent heart failure represents an unmet clinical need. The well conserved lncRNA H19 shows as powerful therapeutic potential in the treatment of pathological cardiac hypertrophy. H19 is strongly repressed in failing hearts from mice, pigs and humans. Gene therapy using murine but also human H19 strongly attenuated heart failure even when cardiac hypertrophy was already established. Using microarray , GSEA and ChIP-Seq we identified a link between H19 and NFAT signalling. H19 physically interacts with PRC2 to epigenetically induced Tescalcin repression which in turn leads to reduced NFAT expression and activity.