Project description:The intermediate filament protein Nestin serves as a biomarker for stem cells and has been used to identify subsets of cancer stem-like cells. However, the mechanistic contributions of Nestin to cancer pathogenesis are not understood. Here we report that Nestin binds the hedgehog pathway transcription factor Gli3 to mediate the development of medulloblastomas of the hedgehog subtype. In a mouse model system, Nestin levels increased progressively during medulloblastoma formation resulting in enhanced tumor growth. Conversely, loss of Nestin dramatically inhibited proliferation and promoted differentiation. Mechanistic investigations revealed that the tumor-promoting effects of Nestin were mediated by binding to Gli3, a zinc finger transcription factor that negatively regulates hedgehog signaling. Nestin binding to Gli3 blocked Gli3 phosphorylation and its subsequent proteolytic processing, thereby abrogating its ability to negatively regulate the hedgehog pathway. Our findings show how Nestin drives hedgehog pathway-driven cancers and uncover in Gli3 a therapeutic target to treat these malignancies. Nestin+ and Nestin- GNPs (granule neuron precursors) were purified from Nestin-CFP/Math1-Cre/Ptch1-loxp cerebella at postnatal day 4 by FACs, and total RNA from these two cell populations were extracted, and then labeled and hybridized to Affymetrix Mouse Genome 430 2.0 arrays.
Project description:This experiment aims to ascertain a profile of secondary metabolites produced by Ilyonectria species capable of causing disappearing root rot in ginseng. Ilyonectria isolates were grown on potato dextrose agar for 20 days, then plugs were taken from the cultures and extracted with ethyl acetate. Extracts were analyzed by LC-HRMS and tandem HRMS. Data were analyzed by Principal component analysis and molecular networking with GNPS.
Project description:Fungal endophytes often live in symbiotic relationships with various plant hosts, conferring positive effects to their host organism. These endophytes frequently produce a wide variety of secondary metabolites with bioactivities that are often responsible for the beneficial effects seen in the host, such as antifungal or anti-insectan activity. A large group of fungal endophytes isolated from Canadian fruit crops including blueberries, raspberries, cranberries, grapes, and pears, was analyzed using molecular networking by GNPS in an effort to simplify the process of examining a large dataset. Molecular networking increased the speed and efficiency of examining this dataset, permitting the dereplication of 60 known compounds and the discovery of seven putative novel compounds, which will be purified, characterized, and tested for bioactivity in future studies.
Project description:Molecular networking has become a key method to visualize and annotate the chemical space in non-targeted mass spectrometry data. We present feature-based molecular networking (FBMN) as an analysis method in the Global Natural Products Social Molecular Networking (GNPS) infrastructure that builds on chromatographic feature detection and alignment tools. FBMN enables quantitative analysis and resolution of isomers, including from ion mobility spectrometry.
Project description:Chemical investigations of Penicillium sp. CMB-STF067 is based on both the antibacterial property of its extract and the Global Natural Product Social (GNPS) molecular networking analysis of 176 soil-associated fungi, guided the isolation of 4-new xanthoquinodins, jugiones A-D.
Project description:Example dataset for Methods in Molecular Biology Chapter - Feature Based Molecular Networking for Metabolite Annotation. This dataset includes the LC-MS/MS raw data (Bruker .d file format and centroided mzXML file format), metadata table used for the ste-by-step instructions, a batch file for MZmine2 data processing, and all resulting files from the MZmine2 and GNPS processing.
Project description:This dataset contains the raw data used for MZmine processing and Feature-based molecular networking of semi-purified fractions obtained from A. timonensis used for bioactive molecular networking to reveal contribution of sulfonolipids to observed biological activity.
Project description:<p>While analytical techniques in natural products research massively shifted to liquid chromatography-mass spectrometry, lichen chemistry remains reliant on limited analytical methods, Thin Layer Chromatography being the gold standard. To meet the modern standards of metabolomics within lichenochemistry, we announce the publication of an open access MS/MS library with 250 metabolites, coined LDB for Lichen DataBase, providing a comprehensive coverage of lichen chemodiversity. These were donated by the Berlin Garden and Botanical Museum from the collection of Siegfried Huneck to be analyzed by LC-MS/MS. Spectra at individual collision energies were submitted to MetaboLights while merged spectra were uploaded to the GNPS platform (CCMSLIB00004751209 to CCMSLIB00004751517). Technical validation was achieved by dereplicating three lichen extracts using a Molecular Networking approach, revealing the detection of eleven unique molecules that would have been missed without LDB implementation to the GNPS. From a chemist's viewpoint, this database should help streamlining the isolation of formerly unreported metabolites. From a taxonomist perspective, the LDB offers a versatile tool for the chemical profiling of newly reported species.</p>