Project description:We isolated an efficient tetracycline degrading strain Sphingobacterium sp. WM1. To investigate gene expression patterns during tetracycline degradation by strain WM1, we conducted a comparative transcriptomic analysis using cultures of strain WM1 with and without tetracycline addition. The RNA-Seq data revealed that 90.44-96.56% of the reads mapped to the genome of Sphingobacterium sp. WM1 across all samples. Differentially expressed genes (DEGs) analysis (|log2FC| >2; p < 0.01) showed that 693 genes were significantly up-regulated and 592 genes were significantly down-regulated.
Project description:MYCN is a master regulator controlling many processes necessary for tumor cell survival. Here, we unravel a microRNA network that causes tumor suppressive effects in MYCN-amplified neuroblastoma cells. In profiling studies, histone deacetylase (HDAC) inhibitor treatment most strongly induced miR-183. Enforced miR-183 expression triggered apoptosis, and inhibited anchorage-independent colony formation in vitro and xenograft growth in mice. Furthermore, the mechanism of miR-183 induction was found to contribute to the cell death phenotype induced by HDAC inhibitors. Experiments to identify the HDAC(s) involved in miR-183 transcriptional regulation showed that HDAC2 depletion induced miR-183. HDAC2 overexpression reduced miR-183 levels and counteracted the induction caused by HDAC2 depletion or HDAC inhibitor treatment. MYCN was found to recruit HDAC2 in the same complexes to the miR-183 promoter, and HDAC2 depletion enhanced promoter-associated histone H4 pan-acetylation, suggesting epigenetic changes preceded transcriptional activation. These data reveal miR-183 tumor suppressive properties in neuroblastoma that are jointly repressed by MYCN and HDAC2, and suggest a novel way to bypass MYCN function.
Project description:MYCN and HDAC2 jointly repress the transcription of tumor suppressive micro RNA miR-183 in neuroblastoma. Enforced miR-183 expression induces neuroblastoma cell death and inhibits anchorage-independent colony formation and subcutaneous xenograft growth in mice. We here aimed to unravel the miR-183 signaling network and elucidated the role of MYCN mediated transcriptional activation of members of the minichromosome maintenance (MCM) family protein family involving miR-183 . The hexamer protein complex formed by MCM proteins is involved in the initiation and elongation of eukaryotic genome replication, thereby contributing to genomic integrity. Analysis of miR-183 versus negative control transfected neuroblastoma cells identified 85 differentially expressed proteins in a label-free mass spectrometric approach. Six members of the MCM family were found to be lower expressed upon enforced miR-183 expression, and subsequent annotation category enrichment analysis revealed a 14-fold enrichment in the protein module category “MCM”. Down-regulation was confirmed by western blot analysis. MicroRNA target prediction software studies revealed that miR-183 was predicted to directly target several MCMs.
Project description:Memory formation is a complex cognitive function regulated by coordinated synaptic and nuclear processes in neurons. In mammals, it is controlled by multiple molecular activators and suppressors, including the key signaling regulator protein phosphatase 1 (PP1). Here, we show that memory control by PP1 involves the miR-183/96/182 cluster, which is selectively regulated during memory formation. Inhibiting nuclear PP1 in mice brain or training in object recognition task similarly increases miR-183/96/182 expression in the hippocampus. Mimicking this increase by overexpressing miR-183/96/182 enhances object memory, while suppressing endogenous level of the cluster reduces it. This effect involves the modulation of many plasticity-related genes, and we identified HDAC9 as one of the functional targets. Further, PP1 controls miR-183/96/182 in a transcription-independent manner influencing processing of their precursors. These findings provide novel evidence for the role of miRNAs in memory formation and suggest the implication of PP1 in miRNAs processing in the adult brain.
Project description:In a field study, trees from two sites in Lower Saxony, Germany, were compared. RNA-seq (performed on an Illumina HiSeq 2000) was conducted on RNA from developing xylem tissue from 4 different harvests throughout the growth season to analyze transcriptional changes related to variations in wood formation and development. A transcriptome contig database was created from the combined raw reads using ABySS. Mapping of reads from distinct samples to the contig database was performed using Bowtie.