Project description:We established a neuron-specific Argonaute2:GFP-RNA immunoprecipitation followed by high throughput sequencing (AGO2-RIP-seq) to analyse the regulatory role of miRNAs in mouse hippocampal neurons. Using this technique, we identified more than two thousand miRNA target genes in hippocampal neurons, regulating essential neuronal features such as axon guidance and transcription. Furthermore, we found that stable inhibition of the highly expressed miR-124 in hippocampal neurons led to significant changes in the AGO2 binding of target mRNAs, resulting in subsequent upregulation of numerous miRNA target genes. Our data suggest that target redundancies are common among microRNA families. Together, these findings greatly enhance our understanding of the mechanisms and dynamics through which miRNAs regulate their target genes in neurons. Analysis of the miRNA targetome in hippocampal neurons after inhibition of 2 different miRNAs. AAV5 injections into the hippocampus of adult C57BL/6 mice producing either of the following under a synapsin promoter: GFP only (Samples beginning with 'GFP124…' or 'GFP125…'), GFP-miR124sp (Samples beginning with 'miR124…'), GFP-miR125sp (Samples beginning with 'miR125…'), GFP-AGO2-miR292sponge (samples ending with '…292'), GFP-AGO2-miR124sponge (samples ending with '…124'), GFP-AGO2-miR125sponge (samples ending with '…125'). All other samples were sham-injected.
Project description:Adult neurogenesis continuously contributes new neurons to hippocampal circuits and the programmed death of a subset of immature cells provides a primary mechanism controlling this contribution. Epileptic seizures induce strong structural changes in the hippocampus, including the induction of adult neurogenesis, changes in gene expression and mitochondrial dysfunction, which may all contribute to epileptogenesis. However, a possible interplay between this factors remains largely unexplored. Here, we investigated gene expression changes in the hippocampal dentate gyrus shortly after prolonged seizures induced by kainic acid, focusing on mitochondrial functions. Using comparative proteomics, we identified networks of proteins differentially expressed shortly after seizure induction, including members of the BCL2 family and other mitochondrial proteins. Within these networks, we report for the first time that the atypical BCL2 protein BCL2L13 controls caspase-3 activity and cytochrome C release in neural stem/progenitor cells. This work has been published in Sci Rep. 2015 Jul 24;5:12448. doi: 10.1038/srep12448.
Project description:We established a neuron-specific Argonaute2:GFP-RNA immunoprecipitation followed by high throughput sequencing (AGO2-RIP-seq) to analyse the regulatory role of miRNAs in mouse hippocampal neurons. Using this technique, we identified more than two thousand miRNA target genes in hippocampal neurons, regulating essential neuronal features such as axon guidance and transcription. Furthermore, we found that stable inhibition of the highly expressed miR-124 in hippocampal neurons led to significant changes in the AGO2 binding of target mRNAs, resulting in subsequent upregulation of numerous miRNA target genes. Our data suggest that target redundancies are common among microRNA families. Together, these findings greatly enhance our understanding of the mechanisms and dynamics through which miRNAs regulate their target genes in neurons.
Project description:miR-137 plays critical roles in the nervous system and tumor development. An increase in its expression is required for neuronal differentiation while its reduction is implicated in gliomagenesis. To evaluate the potential of miR-137 in glioblastoma therapy, we conducted genome-wide target mapping in glioblastoma cells by measuring levels of associations between PABP and mRNAs in cells transfected with miR-137 mimics vs. controls via RIPSeq. Impact on mRNA levels was also measured by RNASeq. By combining the results of both experimental approaches, 1468 genes were determined to be negatively impacted by miR-137; among them, 595 (40%) contain miR-137 predicted sites. The most relevant targets include oncogenic proteins and players in neurogenesis like c-KIT, YBX1, AKT2, CDC42, CDK6 and TGFβ2. Interestingly, we observed that several identified miR-137 targets are also predicted to be regulated by miR-124, miR-128 and miR-7, which are equally implicated in neuronal differentiation and gliomagenesis. We suggest that the concomitant increase of these four miRNAs in neuronal stem cells or their repression in tumor cells could produce a robust regulatory effect with major consequences to neuronal differentiation and tumorigenesis.
Project description:miR-137 plays critical roles in the nervous system and tumor development. An increase in its expression is required for neuronal differentiation while its reduction is implicated in gliomagenesis. To evaluate the potential of miR-137 in glioblastoma therapy, we conducted genome-wide target mapping in glioblastoma cells by measuring levels of associations between PABP and mRNAs in cells transfected with miR-137 mimics vs. controls via RIPSeq. Impact on mRNA levels was also measured by RNASeq. By combining the results of both experimental approaches, 1468 genes were determined to be negatively impacted by miR-137; among them, 595 (40%) contain miR-137 predicted sites. The most relevant targets include oncogenic proteins and players in neurogenesis like c-KIT, YBX1, AKT2, CDC42, CDK6 and TGFβ2. Interestingly, we observed that several identified miR-137 targets are also predicted to be regulated by miR-124, miR-128 and miR-7, which are equally implicated in neuronal differentiation and gliomagenesis. We suggest that the concomitant increase of these four miRNAs in neuronal stem cells or their repression in tumor cells could produce a robust regulatory effect with major consequences to neuronal differentiation and tumorigenesis. Identification of genes affected by miR137 transfection via RIP-Seq and RNA-Seq in U251 and U343 cells
Project description:Recent genetic evidence has revealed microRNA-137 (miR-137) as a risk gene in schizophrenia and autism spectrum disorder (ASD), and the following cellular studies have demonstrated the importance of miR-137 in regulating neurogenesis. We have generated miR-137 knockout mice which display behaviors that resemble some symptoms of these two diseases. To investigate the underlying molecular mechanism, we performed comprehensive analyses of the entire RNA and protein molecules of the miR-137 mouse brains. The dataset uploaded here is the raw data of the mass spectrometry-based whole proteome analysis of the six miR-137 mouse brains: wild-type, heterozygous (miR-137+/–) and homozygous (miR-137–/–) from two different litters. The tandem mass tag (TMT) methodology was employed in this proteomics analysis for the quantitation. The sample channels are: 128C (miR-137+/+, litter 1), 129N (miR-137+/–, litter 1), 129C (miR-137–/–, litter 1), 130N (miR-137+/+, litter 2), 130C (miR-137+/–, litter 2), and 131N (miR-137–/–, litter 2).
Project description:Pheochromocytoma (PCC) and paraganglioma (PGL) are rare neuroendocrine neoplasias of neural crest origin. They can be part of several syndromes, and their mRNA profile is dependent on genetic background, but questions related to clinical behavior or even main location remain unanswered. MicroRNAs are key modulators of target genes through translational repression, mRNA degradation, or both, and therefore they could resolve some of these issues. To determine the role microRNAs play in tumorigenesis and progression of PCC/PGL, as well as to identify microRNA biomarkers specifically related to different PCC/PGL genetic classes known so far, we characterized microRNA profiles in a large series of frozen tumors with germline mutations in SDHD, SDHB, VHL, RET, NF1, and TMEM127 genes through microarray analysis. We identified microRNA signatures specific to, as well as common among, the genetic classes of PCC/PGLs, and the best candidate microRNAs (miR-122, miR-126*, miR-129*, miR-133b, miR-137, miR-183, miR-210, miR-382, miR-488, miR-885-5p, and miR-96) were validated in an independent series of formalin-fixed paraffin-embedded PCC/PGL samples by qRT-PCR. MicroRNA-137, -96/183, and -143/145 expression in PCC/PGLs correlated inversely with the differentiation status of tumor cells. MicroRNA-210, -382, and -380 could modulate pseudohypoxic cellular response in VHL-deficient PCC/PGL. MicroRNA-193b, -365, and -424 were commonly downregulated among all genetic classes, suggesting their involvement in cell cycle control and differentiation. Herein, we demonstrate that PCC/PGLs have different microRNA profiles according to the underlying primary mutation, suggesting they could be used as specific biomarkers and add information on the etiology of these tumors.
Project description:This phase I trial studies how well an imaging agent called I-124 M5A works in detecting CEA-positive colorectal cancer that has spread to the liver. I-124 M5A is a monoclonal antibody, called M5A, linked to a radioactive substance called I-124. M5A binds to CEA-positive cancer cells and may, through imaging scans, be able to detect liver metastases by picking up signals from I-124.