Project description:Primary outcome(s): Relationship with mRNA expression of B7 family molecules in blood of patients with colorectal cancer and clinicopathological factors
Project description:circHIPK3 silencing impairs ß-cell functions leading to a decrease in insulin secretion, proliferation, and survival. Therefore, we wanted to identify the mode of action of circHIPK3 by measuring gene expression changes upon circHIPK3 silencing in MIN6B1 cells.
Project description:We performed a label free mass spectrometry-based proteomic analysis to investigate the effects of PCYOX1 silencing on the secretome of human HepG2 cells
Project description:The change of mRNA expression in murine immortalized podocyte were analyzed after miR-26a silencing. These results provide a basical information of molecular pathology in podocyte biology.
Project description:In animals Argonaute small-RNA pathways scan germline transcripts to silence self-replicating genetic elements. Little is known however about how endogenous gene expression is recognized and licensed. Here we show that the presence of introns and by inference the process of mRNA splicing prevents default Argonaute-mediated silencing in the C. elegans germline. Silencing of intronless genes is initiated independently of the piRNA pathway but nevertheless engages multiple components of the downstream amplification and maintenance mechanisms that mediate transgenerational silencing including both nuclear and cytoplasmic members of the worm-specific Argonaute gene family (WAGOs). Small RNAs amplified from intronless mRNAs can trans-silence cognate intron-containing genes. Interestingly, a second small RNA-independent cis-acting mode of silencing also acts on intronless mRNAs. Our findings suggest that cues put in place during mRNA splicing license germline gene expression and provide evidence for a splicing-dependent and dsRNA- and piRNA-independent mechanism that can program Argonaute silencing.
Project description:<p>Translation fidelity is the limiting factor in the accuracy of gene expression. With an estimated frequency of 10-4, errors in mRNA decoding occur in a mostly stochastic manner. Little is known about the response of higher eukaryotes to chronic loss of ribosomal accuracy as per an increase in the random error rate of mRNA decoding. Here, we present a global and comprehensive picture of the cellular changes in response to translational accuracy in mammalian ribosomes impaired by genetic manipulation. In addition to affecting established protein quality control pathways, such as elevated transcript levels for cytosolic chaperones, activation of the ubiquitin-proteasome system, and translational slowdown, ribosomal mistranslation led to unexpected responses. In particular, we observed increased mitochondrial biogenesis associated with import of misfolded proteins into the mitochondria and silencing of the unfolded protein response in the endoplasmic reticulum.</p><p><br></p><p>This study describes the metabolomic analysis of HEK293 cells lines expressing mutant ribosomal protein RPS2 (human A226Y). RPS2 A226Y mutation has been shown to cause misreading and readthrough. Results provide insight into the response to chronic mistranslation in mammalian cells.</p>
Project description:RNA silencing is one of the main defense mechanisms employed by plants to fight viruses. In change, viruses have evolved silencing suppressor proteins to neutralize antiviral silencing. Since the endogenous and antiviral functions of RNA silencing pathway rely on common components, it was suggested that viral suppressors interfere with endogenous silencing pathway contributing to viral symptom development. In this work, we aimed to understand the effects of the tombusviral p19 suppressor on endogenous and antiviral silencing during genuine virus infection. We showed that ectopically expressed p19 sequesters endogenous small RNAs (sRNAs) in the absence, but not in the presence of virus infection. Our presented data question the generalized model in which the sequestration of endogenous sRNAs by the viral suppressor contributes to the viral symptom development. We further showed that p19 preferentially binds the perfectly-paired ds-viral small interfering RNAs (vsiRNAs) but does not select based on their sequence or the type of the 5’ nucleotide. Finally, co-immunoprecipitation of sRNAs with AGO1 or AGO2 from virus-infected plants revealed that p19 specifically impairs vsiRNA loading into AGO1 but not AGO2. Our findings, coupled with the fact that p19-expressing wild type Cymbidium ringspot virus (CymRSV) overcomes the Nicotiana benthamiana silencing based defense killing the host, suggest that AGO1 is the main effector of antiviral silencing in this host-virus combination. To further support our hypothesis we investigate whether the ability of p19 to bind endogenous sRNA without virus infection has biological important impact on endogenous pathways and is this reduced if the virus is present. To asses this we made mRNA sequencing from mock inoculated and Cym19stop infected p19syn plants. Cym19stop infected wild type plant was sequenced as a control. The sequencing data results supports our claims. An increase in transcriptional levels were found in case of genes known to be under small RNA regulation in uninfected p19syn plants and expressional levels return to normal Cym19stop p19syn plants.
Project description:RNA undergoes numerous processing steps required for gene expression. Little is known about RNA homeostasis during environmental stress in metazoan cells. By studying regulation of a heavy metal-induced gene named numr-1 in C. elegans, we discovered that disruption of RNA processing acts as a signal for environmental stress. We find that NUMR-1 contains motifs common to RNA splicing factors and regulates RNA splicing in vivo. A genome-wide screen reveals that numr-1 is strongly and specifically induced by silencing of genes that function in basal RNA metabolism including subunits of the metazoan integrator complex. Human integrator processes snRNAs for functioning with splicing factors, and we find that silencing of C. elegans integrator subunits disrupts snRNA processing and causes aberrant pre-mRNA splicing. Cadmium, which also strongly induces numr-1, has the same effects on snRNA processing and pre-mRNA splicing. Lastly, we find that heat shock factor-1 is required for numr-1 induction by cadmium. Our results are consistent with a model in which disruption of integrator processing of RNA acts as a molecular damage signal initiating an adaptive stress response mediated by heat shock factor-1.