Project description:Here, we present a standardized, “off-the-shelf” proteomics pipeline working in a single 96-well plate to achieve deep coverage of cellular proteomes with high throughput and scalability. This integrated pipeline streamlining a fully automated sample preparation platform, data independent acquisition (DIA) coupled with high field asymmetric waveform ion mobility spectrometer (FAIMS) interface, and an optimized library-free DIA database search strategy. Our systematic evaluation of FAIMS-DIA showed single compensation voltage (CV) at -35V not only yields deepest proteome coverage but also best correlates with DIA without FAIMS. Our in-depth comparison of direct-DIA database search engines showed Spectronaut outperforms others, providing highest quantifiable proteins. Next, we apply three common DIA strategies in characterizing human induced pluripotent stem cell (iPSC)-derived neurons and show single-shot MS using single CV(-35V)-FAIMS-DIA results in >9,000 quantifiable proteins with < 10% missing values, as well as superior reproducibility and accuracy compared to other existing DIA methods.
Project description:Induced pluripotent stem cells (iPSCs) harbor great promise for in vitro generation of disease-relevant cell types, such as mesodiencephalic dopaminergic (mdDA) neurons involved in Parkinson’s disease. Although iPSC-derived midbrain DA neurons have been generated, detailed genetic and epigenetic characterization of such neurons is still lacking. The goal of this study is to examine the authenticity of iPSC-derived DA neurons obtained by established protocols. We FACS-purified mdDA (Pitx3gfp/+) neurons derived from mouse iPSCs and primary mdDA (Pitx3gfp/+) neurons to analyze and compare their genetic and epigenetic features. Although iPSC-derived DA neurons largely adopt characteristics of their in-vivo counterparts, relevant deviations in global gene expression and DNA methylation were found. Hypermethylated genes, mainly involved in neurodevelopment and basic neuronal functions, consequently showed reduced expression levels. Such abnormalities should be addressed as they might affect unambiguous long-term functionality and hamper the potential of iPSC-derived DA neurons for in-vitro disease modeling or cell-based therapy. RRBS methylation maps were generated for iPSCs cells, dopaminergic neurons derived from iPSCs and primary mesodiencephalic dopaminergic neurons
Project description:Biallelic mutations in the gene that encodes the enzyme N-glycanase 1 (NGLY1) cause a rare disease with multi-symptomatic features including developmental delay, intellectual disability, neuropathy and seizures. NGLY1’s activity in human neural cells is currently not well understood. To understand how NGLY1 gene loss leads to the specific phenotypes of NGLY1 deficiency, we employed direct conversion of NGLY1 patient-derived induced pluripotent stem cells (iPSCs) to functional cortical neurons. Transcriptomic, proteomic, and functional studies of iPSC-derived neurons lacking NGLY1 function revealed several major cellular processes that were altered, including protein aggregate-clearing functionality, mitochondrial homeostasis, and synaptic dysfunctions. These phenotypes were rescued by introduction of a functional NGLY1 gene and were observed in iPSC-derived mature neurons, but not astrocytes. Finally, laser capture microscopy followed by mass spectrometry provided detailed characterization of the composition of protein aggregates specific to NGLY1-deficient neurons. Future studies will harness this knowledge for therapeutic development.
Project description:Transcription factor binding locations by ChIP followed by high throughput sequencing. To build and validate an automated Chromatin Immunoprecipitation and high throughput Illumina sequencing pipeline
Project description:Induced pluripotent stem cells (iPSCs) hold great promise for in vitro disease modeling and cell replacement therapy for Parkinson’s disease (PD). Both applications crucially require an in-depth profiling of the disease-relevant, iPSC-derived cell type. Midbrain dopaminergic (mDA) neurons derived from pluripotent stem cells are of substantial interest because of their instrumental value for PD therapy. IPSC-derived mDA neuron-like cells have been generated, however, detailed genetic and epigenetic characterization of strictly purified in vitro generated DA neurons has so far lagged behind. We generated mouse Pitx3gfp/+ iPSC-derived DA neurons that, after fluorescent activated cell sorting (FACS) allowed comprehensive comparison to mesodiencephalic dopaminergic (mdDA) neurons from Fac-sorted Pitx3gfp/+ ventral midbrains. We performed detailed analysis of global gene expression and genome-scale DNA methylation of CpG islands (CGIs) by reduced representation bisulfite sequencing. The reprogramming pathway from fibroblasts to iPSCs left parental cell footprints for both gene expression and DNA methylation. However, most gene expression patterns of iPSC-derived DA neurons closely resembled that of primary mdDA neurons with the strongest correlations for mdDA specific genes. Also, for DNA methylation patterns, high similarities were found for the vast majority of CGIs when comparing primary mdDA neurons with iPSC-derived DA neurons. Additionally, we found de novo DNA methylation during in vitro differentiation for hundreds of genes specifically in lineage-committed neural precursors that persisted in iPSC-derived DA neurons. Our study provides novel detailed characteristics of iPSC-derived DA neurons in comparison to the primary cell type. These findings add important information to our knowledge about these biomedically highly valuable, in vitro generated neurons. Microarray expression study comparing 3 samples of facs-sorted, Pitx3-gfp positive cells from each experimental group to a common reference consisting of adult mouse midbrain RNA. Each sample was analysed in normal and opposite dye orientation.
Project description:We have developed DIA-NN, an integrated software suite for fully-automated processing of raw SWATH/DIA data. DIA-NN enables deep and confident proteome coverage with fast chromatographic methods, paving the way for a new generation of high-throughput proteomics. This data set illustrates the capabilities of DIA-NN when analysing microflow SWATH data acquired with 19 - 23 minute gradients as well as the use of DIA-NN to generate spectral libraries directly from SWATH/DIA data.
Project description:Primary objectives: Characterization of the macrophage population subset that is modulated by enteric neurons
Primary endpoints: Characterization of the macrophage population subset that is modulated by enteric neurons via RNA sequencing
Project description:Biallelic mutations in the gene that encodes the enzyme N-glycanase 1 (NGLY1) cause a rare disease with multi-symptomatic features including developmental delay, intellectual disability, neuropathy and seizures. NGLY1’s activity in human neural cells is currently not well understood. To understand how NGLY1 gene loss leads to the specific phenotypes of NGLY1 deficiency, we employed direct conversion of NGLY1 patient-derived induced pluripotent stem cells (iPSCs) to functional cortical neurons. Transcriptomic, proteomic, and functional studies of iPSC-derived neurons lacking NGLY1 function revealed several major cellular processes that were altered, including protein aggregate-clearing functionality, mitochondrial homeostasis, and synaptic dysfunctions. These phenotypes were rescued by introduction of a functional NGLY1 gene and were observed in iPSC-derived mature neurons, but not astrocytes. Finally, laser capture microscopy followed by mass spectrometry provided detailed characterization of the composition of protein aggregates specific to NGLY1-deficient neurons. Future studies will harness this knowledge for therapeutic development.
Project description:Induced pluripotent stem cells (iPSCs) harbor great promise for in vitro generation of disease-relevant cell types, such as mesodiencephalic dopaminergic (mdDA) neurons involved in Parkinson’s disease. Although iPSC-derived midbrain DA neurons have been generated, detailed genetic and epigenetic characterization of such neurons is still lacking. The goal of this study is to examine the authenticity of iPSC-derived DA neurons obtained by established protocols. We FACS-purified mdDA (Pitx3gfp/+) neurons derived from mouse iPSCs and primary mdDA (Pitx3gfp/+) neurons to analyze and compare their genetic and epigenetic features. Although iPSC-derived DA neurons largely adopt characteristics of their in-vivo counterparts, relevant deviations in global gene expression and DNA methylation were found. Hypermethylated genes, mainly involved in neurodevelopment and basic neuronal functions, consequently showed reduced expression levels. Such abnormalities should be addressed as they might affect unambiguous long-term functionality and hamper the potential of iPSC-derived DA neurons for in-vitro disease modeling or cell-based therapy.