Project description:By combining chromatin immunoprecipitation (ChIP) with an exonuclease that digests the ends of protein-bound DNA fragments, ChIP-exo characterizes genome-wide protein-DNA interactions at near base-pair resolution. However, the widespread adoption of ChIP-exo has been hindered by several technical challenges, including lengthy protocols, the need for multiple custom reactions, and incompatibilities with recent Illumina sequencing platforms. To address these barriers, we systematically optimized and adapted the ChIP-exo library construction protocol for the unique requirements of mammalian cells and current sequencing technologies. We introduce a Mammalian-Optimized ChIP-exo (MO-ChIP-exo) protocol that builds upon previous ChIP-exo protocols with systematic optimization of crosslinking, harvesting, and library construction. We validate MO-ChIP-exo by comparing it to previously published ChIP-exo protocols and demonstrate its adaptability to both suspension (K562) and adherent (HepG2, mESC) cell lines. This improved protocol provides a more robust and efficient method for generating high-quality ChIP-exo libraries from mammalian cells.
Project description:The emerging evidences support that exosome cargo miRNAs function as important regulators in cell differentiation. Therefore, in order to figure out the mechanism that Exo-AT mediated adipogenesis, we profiled miRNAs in Exo-AT using high-throughput sequencing (miRNA-seq). After trimming low-quality reads, contaminants, adaptors, and reads smaller than 15 nt, the remaining reads were mapped to merged pre-miRNA data bases. To identify the conserved miRNAs in Exo exosomes, miRNAs were aligned to miRBase v21. 148 and 154 types of known miRNAs in Exo-ADSCs and Exo-AT, respectively, were identified in the two replicates. Among these miRNAs, 103 miRNAs were simultaneously detected in both Exo-ADSCs and Exo-AT. Compared to Exo-ADSCs, 45 conserved miRNAs were enriched (expressed ≥ 2 folds, FDR<0.05) in Exo-AT. KEGG Pathway analysis was performed for the targets of the most 20 enriched miRNAs in Exo-AT (compared with Exo-ADSCs) to determine their potential function. Data showed that pathways that regulate adipogenesis such as Wnt signaling pathway, Insulin signaling pathway, MAPK signaling pathway, TGF-ß signaling pathway were enriched significantly for targets of Exo-AT miRNAs. Furthermore, 14 of 45 enriched miRNAs in Exo-AT (31.11%, such as miR-30a-5p, miR-148a-3p) were reported to participate in regulation of adipogenesis while 8 miRNAs (17.78%, such as miR-93-5p, miR-150-3p) that negatively control osteoblastic differentiation of MSC have been described.
Project description:Loss of contractility and acquisition of an epithelial phenotype of vascular smooth muscle cells (VSMCs) are key events in proliferative vascular pathologies such as atherosclerosis and post-angioplastic restenosis. There is no proper cell culture system allowing VSMC differentiation so that it is difficult to delineate the molecular mechanism responsible for proliferative vasculopathy. We investigated whether a micro-patterned substrate could restore the contractile phenotype of VSMCs in vitro. To induce and maintain the differentiated VSMC phenotype in vitro, we introduced a micro-patterned groove substrate to modulate the morphology and function of VSMCs.
Project description:To explore the possibility of miRNA(s) contributing to the cardioprotection induced by plasma exosomes at the late phase of RIPC, we performed a miRNA profiling assay (763 rat miRNAs) comparing the differences between RIPC-exo and Control-exo using Illumina HiSeq 2500 high-throughput sequencing.
Project description:Chromatin immunoprecipitation followed by deep sequencing (ChIP-seq) and its ultra-high resolution cousin ChIP-exo are methods that identify where proteins bind along any genome in vivo. ChIP-exo achieves near-base pair resolution by creating exonuclease stop sites just 5’ to where formaldehyde-induced protein-DNA cross-links occur. Whereas construction of ChIP genomic libraries is straightforward and widely adopted for ChIP-seq, ChIP-exo is technically more involved which has resulted in limited adoption. Here we describe multiple ChIP-exo protocols, each with use-specific advantages and limitations. The new versions are greatly simplified through removal of multiple enzymatic steps. This is achieved in part through the use of Tn5 tagmentation and/or single-stranded DNA ligation. The result is greater library yields, lower processing time, and lower cost. A similar streamlined approach was developed for ChIP-seq, called ChIP-seq 1-step, where library construction is achieved in one-step.
Project description:Spatial transcriptomics workflows using barcoded capture arrays are commonly used for resolving gene expression in tissues. However, existing techniques are either limited by capture array density or are cost prohibitive for large scale atlasing. We present Nova-ST, a dense nano-patterned spatial transcriptomics technique derived from randomly barcoded Illumina sequencing flow cells. Nova-ST enables customized, low cost, flexible, and high-resolution spatial profiling of large tissue sections. Benchmarking on mouse brain sections demonstrates significantly higher sensitivity compared to existing methods, at reduced cost.
Project description:Spatial transcriptomics workflows using barcoded capture arrays are commonly used for resolving gene expression in tissues. However, existing techniques are either limited by capture array density or are cost prohibitive for large scale atlasing. We present Nova-ST, a dense nano-patterned spatial transcriptomics technique derived from randomly barcoded Illumina sequencing flow cells. Nova-ST enables customized, low cost, flexible, and high-resolution spatial profiling of large tissue sections. Benchmarking on mouse brain sections demonstrates significantly higher sensitivity compared to existing methods, at reduced cost.
Project description:We established a micro-patterned respiratory epithelial cell culture system in vitro. In this culture system, various types of lung epithelial cells were identified.