Uncovering uncharacterized binding of transcription factors from ATAC-seq footprinting data

Transcription factors (TFs) are crucial epigenetic regulators, which enable cells to dynamically adjust gene expression in response to environmental signals. Computational procedures like digital genomic footprinting on chromatin accessibility assays such as ATACseq can be used to identify bound TFs in a genome-wide scale. This method utilizes short regions of low accessibility signals due to steric hindrance of DNA bound proteins, called footprints (FPs), which are combined with motif databases for TF identification. However, while over 1600 TFs have been described in the human genome, only ~ 700 of these have a known binding motif. Thus, a substantial number of FPs without overlap to a known DNA motif are normally discarded from FP analysis. In addition, the FP method is restricted to organisms with a substantial number of known TF motifs. Here we present DENIS (DE Novo motIf diScovery), a framework to generate and systematically investigate the potential of de novo TF motif discovery from FPs. DENIS includes functionality (1) to isolate FPs without binding motifs, (2) to perform de novo motif generation and (3) to characterize novel motifs. Here, we show that the framework rediscovers artificially removed TF motifs, quantifies de novo motif usage during an early embryonic development example dataset, and is able to analyze and uncover TF activity in organisms lacking canonical motifs. The latter task is exemplified by an investigation of a scATAC-seq dataset in zebrafish which covers different cell types during hematopoiesis.

TF-COMB - discovering grammar of transcription factor binding sites

Cooperativity between transcription factors is important to regulate target gene expression. In particular, the binding grammar of TFs in relation to each other, as well as in the context of other genomic elements, is crucial for TF functionality. However, tools to easily uncover co-occurrence between DNA-binding proteins, and investigate the regulatory modules of TFs, are limited. Here we present TF-COMB (Transcription Factor Co-Occurrence using Market Basket analysis) - a tool to investigate co-occurring TFs and binding grammar within regulatory regions. We found that TF-COMB can accurately identify known co-occurring TFs from ChIP-seq data, as well as uncover preferential localization to other genomic elements. With the use of ATAC-seq footprinting and TF motif locations, we found that TFs exhibit both preferred orientation and distance in relation to each other, and that these are biologically significant. Finally, we extended the analysis to not only investigate individual TF pairs, but also TF pairs in the context of networks, which enabled the investigation of TF complexes and TF hubs. In conclusion, TF-COMB is a flexible tool to investigate various aspects of TF binding grammar.

WIlsON: Web-based Interactive Omics VisualizatioN

Motivation

High throughput (HT) screens in the omics field are typically analyzed by automated pipelines that generate static visualizations and comprehensive spreadsheet data for scientists. However, exploratory and hypothesis driven data analysis are key aspects of the understanding of biological systems, both generating extensive need for customized and dynamic visualization.

Results

Here we describe WIlsON, an interactive workbench for analysis and visualization of multi-omics data. It is primarily intended to empower screening platforms to offer access to pre-calculated HT screen results to the non-computational scientist. Facilitated by an open file format, WIlsON supports all types of omics screens, serves results via a web-based dashboard, and enables end users to perform analyses and generate publication-ready plots.

Availability and implementation

We implemented WIlsON in R with a focus on extensibility using the modular Shiny and Plotly frameworks. A demo of the interactive workbench without limitations may be accessed at http://loosolab.mpi-bn.mpg.de. A standalone Docker container as well as the source code of WIlsON are freely available from our Docker hub https://hub.docker. com/r/loosolab/wilson, CRAN https://cran.r-project.org/web/packages/wilson/, and GitHub repository https://github.molgen.mpg.de/loosolab/wilson-apps, respectively.

Struktur- und Prozessqualität der stationären urologischen Rehabilitation

Inpatient rehabilitation and "Anschlussheilbehandlung" (rehabilitation soon after operation or acute intervention) are effective and economic for long-term improvement of urologic patients. Only therapy guided by urologic specialists during rehabilitation and afterwards guarantees the possibility of excellent results. Especially QOL and functional deficits are improved markedly by urologic rehabilitation. Therefore, inpatient urologic rehabilitation should be initiated more often in the future.

[Clinical significance of bacterial beta-lactamase production in the treatment of urinary tract infections with oral beta-lactam-antibiotics]

In 649 urological patients with urinary tract infections (UTI) a total of 1114 bacterial strains were isolated and their beta-lactamase production was investigated by a qualitative, micro-iodometric method. Approximately 40% of all strains, 33% of E. coli species and 8% of Proteus mirabilis species were enzyme producers. All of the isolates of E. coli and Proteus mirabilis defined as non-producers were sensitive to ampicillin and cephalothin in the agar diffusion test. The beta-lactamase producers of these two species did not show the same pattern: almost all of them were ampicillin-resistant, but most were cephalothin-sensitive. The other species were all found to be either producers or non-producers. Therapeutic comparisons in altogether 138 UTI patients treated with ampicillin or cephalexin, two antibiotics with different beta-lactamase stability, confirmed the positive correlation between enzyme production and therapeutic failure in both groups. Cephalexin, however, tended to be more effective than ampicillin against enzyme-producing species.