Project description:RNA-seq samples from 3 species across a differentiation from induced pluripotent stem cells to neural progenitor cells were generated to study gene expression evolution. Briefly, previously generated urinary stem cell derived iPSCs of 3 human (Homo sapiens) individuals (3 clones), 1 gorilla (Gorilla gorilla) individual and fibroblast derived cynomolgus macaque (Macaca fascicularis) iPSCs of 2 individuals (4 clones) (Geuder et al. 2021) were differentiated to neural progenitor cells via dual-SMAD inhibition as three-dimensional aggregation culture (Chambers et al. 2009; Ohnuki et al. 2014). Bulk RNA-seq libraries of iPSCs and NPCs were generated using prime-seq protocol (Janjic et al. 2022).
Project description:Transcriptional profiling of human mesenchymal stem cells comparing normoxic MSCs cells with hypoxic MSCs cells. Hypoxia may inhibit senescence of MSCs during expansion. Goal was to determine the effects of hypoxia on global MSCs gene expression.
Project description:We have utilized induced pluripotent stem cells (iPSCs) derived from Huntington’s disease patients (HD iPSCs) as a human model of HD and determined that the disease phenotypes only manifest in the differentiated neural stem cell (NSC) stage, not in iPSCs. To understand the molecular basis for the CAG repeat expansion dependent disease phenotypes in NSCs, we performed transcriptomic analysis of HD iPSCs and HD NSCs compared to isogenic controls using RNA-Seq. Differential gene expression and pathway analysis pointed to TGF-b and netrin-1 as the top dysregulated pathways. Using data driven gene coexpression network analysis, we identified seven distinct coexpression modules, and focused on two that were correlated with changes in gene expression in NSC due to the CAG expansion. Strikingly, our HD NSC model revealed the dysregulation of genes involved in neuronal development and the formation of the dorsal striatum in HD. Further, the striatal specific and neuronal networks disrupted could be modulated to correct HD phenotypes and provide novel therapeutic targets for HD
Project description:We have sequenced miRNA libraries from human embryonic, neural and foetal mesenchymal stem cells. We report that the majority of miRNA genes encode mature isomers that vary in size by one or more bases at the 3’ and/or 5’ end of the miRNA. Northern blotting for individual miRNAs showed that the proportions of isomiRs expressed by a single miRNA gene often differ between cell and tissue types. IsomiRs were readily co-immunoprecipitated with Argonaute proteins in vivo and were active in luciferase assays, indicating that they are functional. Bioinformatics analysis predicts substantial differences in targeting between miRNAs with minor 5’ differences and in support of this we report that a 5’ isomiR-9-1 gained the ability to inhibit the expression of DNMT3B and NCAM2 but lost the ability to inhibit CDH1 in vitro. This result was confirmed by the use of isomiR-specific sponges. Our analysis of the miRGator database indicates that a small percentage of human miRNA genes express isomiRs as the dominant transcript in certain cell types and analysis of miRBase shows that 5’ isomiRs have replaced canonical miRNAs many times during evolution. This strongly indicates that isomiRs are of functional importance and have contributed to the evolution of miRNA genes
